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Gonçalves LFFF, Reis RL, Fernandes EM. Forefront Research of Foaming Strategies on Biodegradable Polymers and Their Composites by Thermal or Melt-Based Processing Technologies: Advances and Perspectives. Polymers (Basel) 2024; 16:1286. [PMID: 38732755 PMCID: PMC11085284 DOI: 10.3390/polym16091286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/13/2024] [Accepted: 04/26/2024] [Indexed: 05/13/2024] Open
Abstract
The last few decades have witnessed significant advances in the development of polymeric-based foam materials. These materials find several practical applications in our daily lives due to their characteristic properties such as low density, thermal insulation, and porosity, which are important in packaging, in building construction, and in biomedical applications, respectively. The first foams with practical applications used polymeric materials of petrochemical origin. However, due to growing environmental concerns, considerable efforts have been made to replace some of these materials with biodegradable polymers. Foam processing has evolved greatly in recent years due to improvements in existing techniques, such as the use of supercritical fluids in extrusion foaming and foam injection moulding, as well as the advent or adaptation of existing techniques to produce foams, as in the case of the combination between additive manufacturing and foam technology. The use of supercritical CO2 is especially advantageous in the production of porous structures for biomedical applications, as CO2 is chemically inert and non-toxic; in addition, it allows for an easy tailoring of the pore structure through processing conditions. Biodegradable polymeric materials, despite their enormous advantages over petroleum-based materials, present some difficulties regarding their potential use in foaming, such as poor melt strength, slow crystallization rate, poor processability, low service temperature, low toughness, and high brittleness, which limits their field of application. Several strategies were developed to improve the melt strength, including the change in monomer composition and the use of chemical modifiers and chain extenders to extend the chain length or create a branched molecular structure, to increase the molecular weight and the viscosity of the polymer. The use of additives or fillers is also commonly used, as fillers can improve crystallization kinetics by acting as crystal-nucleating agents. Alternatively, biodegradable polymers can be blended with other biodegradable polymers to combine certain properties and to counteract certain limitations. This work therefore aims to provide the latest advances regarding the foaming of biodegradable polymers. It covers the main foaming techniques and their advances and reviews the uses of biodegradable polymers in foaming, focusing on the chemical changes of polymers that improve their foaming ability. Finally, the challenges as well as the main opportunities presented reinforce the market potential of the biodegradable polymer foam materials.
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Affiliation(s)
- Luis F. F. F. Gonçalves
- 3B’s Research Group, I3Bs–Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, Barco, 4805-017 Guimarães, Portugal;
- ICVS/3B’s—PT Government Associate Laboratory, Barco, 4805-017 Guimarães, Portugal
| | - Rui L. Reis
- 3B’s Research Group, I3Bs–Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, Barco, 4805-017 Guimarães, Portugal;
- ICVS/3B’s—PT Government Associate Laboratory, Barco, 4805-017 Guimarães, Portugal
| | - Emanuel M. Fernandes
- 3B’s Research Group, I3Bs–Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, Barco, 4805-017 Guimarães, Portugal;
- ICVS/3B’s—PT Government Associate Laboratory, Barco, 4805-017 Guimarães, Portugal
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2
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Wu M, Ren Q, Zhu X, Li W, Luo H, Wu F, Wang L, Zheng W, Cui P, Yi X. Super toughened blends of poly(lactic acid) and poly(butylene adipate-co-terephthalate) injection-molded foams via enhancing interfacial compatibility and cellular structure. Int J Biol Macromol 2023:125490. [PMID: 37348589 DOI: 10.1016/j.ijbiomac.2023.125490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/08/2023] [Accepted: 06/18/2023] [Indexed: 06/24/2023]
Abstract
Biodegradable poly(lactic acid) (PLA) foams have drawn increasing attention due to environmental challenges and petroleum crisis. However, it still remains a challenge to prepare PLA foams with fine cellular structures and high impact property, which significantly hinders its widespread application. Herein, phase interface-enhanced PLA/ poly(butylene adipate-co-terephthalate) (PBAT) blend foam, modified by a reactive compatibilizer through a simple reactive extrusion, was produced via a core-back foam injection molding technique. The obtained PLA blend foams displayed an impact strength as high as 49.1 kJ/m2, which was 9.3 and 6.4 times that of the unmodified PLA/PBAT blend and its corresponding foam, respectively. It proved that the interfacial adhesion and cell size both strongly affected the impact strength of injection-molded PLA/PBAT foams, and two major conclusions were proposed. First, enhancing interfacial adhesion could cause a brittle-tough transition of PLA/PBAT foams. Additionally, for foams with high interfacial adhesion, small cell size (<12 μm) was more favorable for the stretching of cells and extension of the whitened region in comparison with big cell size (cell size >60 μm), leading to the drastic toughening of PLA blends. This study provides a feasible, industrially scalable and practical strategy to prepare super toughened and fully biodegradable PLA materials.
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Affiliation(s)
- Minghui Wu
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province 315201, PR China; Faculty of Science and Engineering, University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo 315000, PR China
| | - Qian Ren
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province 315201, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xiuyu Zhu
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province 315201, PR China
| | - Wanwan Li
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province 315201, PR China
| | - Haibin Luo
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province 315201, PR China
| | - Fei Wu
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province 315201, PR China
| | - Long Wang
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province 315201, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Wenge Zheng
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province 315201, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Ping Cui
- Faculty of Science and Engineering, University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo 315000, PR China
| | - Xiaosu Yi
- Faculty of Science and Engineering, University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo 315000, PR China
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A facile strategy for preparation of strong tough poly(lactic acid) foam with a unique microfibrillated bimodal micro/nano cellular structure. Int J Biol Macromol 2022; 199:264-274. [PMID: 34999040 DOI: 10.1016/j.ijbiomac.2021.12.187] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/12/2021] [Accepted: 12/29/2021] [Indexed: 12/13/2022]
Abstract
This work reports the design and fabrication of strong tough poly(lactic acid) (PLA) foam by combining pressure-induced-flow (PIF) processing with supercritical CO2 foaming. PIF processing widened the foaming window of PLA to 40-120 °C, while supercritical CO2 foaming released the undesired internal stress of PLA samples with PIF processing (P-PLA). The prepared PLA foams displayed a unique microfibrillated bimodal micro/nano cellular structure which is strongly affected by saturation temperature (Ts). Both micron and nano cells showed decreasing cells size and increasing cell density as Ts elevated. The orientation factor as well as internal stress of PLA foams decreased with increased Ts. Compared with P-PLA samples, PLA foam prepared at Ts of 40 °C showed negligible reduction of orientation from 0.45 to 0.41 and release of internal stress characterized by the rightward shift of Raman peak (stretching vibration of CO bond from 1763 to 1766 cm-1). Furthermore, PLA foam prepared at Ts of 40 °C presented excellent impact strength (32.3 kJ/m2), tensile strength (42.0 MPa), and ductility (14.2%). The combination of PIF processing and supercritical CO2 foaming provides a facile and effective method to prepare strong tough PLA foam that has immense potential in biomedical, aerospace, automotive, and other structural applications.
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Venkatesan KB, Karkhanis SS, Matuana LM. Microcellular foaming of poly(lactic acid) branched with food‐grade chain extenders. J Appl Polym Sci 2021. [DOI: 10.1002/app.50686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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5
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Kastner C, Steinbichler G, Kahlen S, Jerabek M, Lummerstorfer T. Nonlinear influences of process parameters on mechanical properties of physically foamed, fiber‐reinforced polypropylene parts. J Appl Polym Sci 2020. [DOI: 10.1002/app.49569] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Clemens Kastner
- Institute of Polymer Injection Molding and Process Automation Johannes Kepler University Linz Linz Austria
- Competence Center CHASE GmbH Linz Austria
| | - Georg Steinbichler
- Institute of Polymer Injection Molding and Process Automation Johannes Kepler University Linz Linz Austria
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Chen J, Yang L, Chen D, Mai Q, Wang M, Wu L, Kong P. Cell structure and mechanical properties of microcellular PLA foams prepared via autoclave constrained foaming. CELLULAR POLYMERS 2020. [DOI: 10.1177/0262489320930328] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Microcellular polylactic acid (PLA) foams with various cell size and cell morphologies were prepared using supercritical carbon dioxide (sc-CO2) solid-state foaming to investigate the relationship between the cell structure and mechanical properties. Constrained foaming was used and a wide range of cell structures with a constant porosity of ∼75% by tuning saturation pressure (8–24 MPa) was developed. Experiments varying the saturation pressure while holding other variables’ constant show that the mean cell size and the mean cell wall thickness decreased, while the cell density and the open porosity increased with increase of pressure. Tensile modulus of PLA foams decreased with increasing the saturation pressure, but the specific tensile modulus of PLA foams was still 15–80% higher than that of solid PLA. Tensile strength and elongation at break first increased with increasing saturation pressure up to 16 MPa and then decreased with further increasing saturation pressure (20 MPa and 24 MPa) at which opened-cell structure produced. Compressive modulus, compressive strength, and compressive yield stress also followed the same variation trend. The results indicated that not only cell size plays an important role in properties of PLA foams but also cell morphology can influence these properties significantly.
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Affiliation(s)
- Jinwei Chen
- Department of Polymer Processing, Advanced Research Center for Polymer Processing Engineering of Guangdong Province, Guangzhou, People’s Republic of China
- School of Light Chemical Technology, Guangdong Industry Technical College, Guangzhou, People’s Republic of China
| | - Ling Yang
- School of Light Chemical Technology, Guangdong Industry Technical College, Guangzhou, People’s Republic of China
| | - Dahua Chen
- Department of Polymer Processing, Advanced Research Center for Polymer Processing Engineering of Guangdong Province, Guangzhou, People’s Republic of China
- School of Light Chemical Technology, Guangdong Industry Technical College, Guangzhou, People’s Republic of China
| | - Qunshan Mai
- School of Light Chemical Technology, Guangdong Industry Technical College, Guangzhou, People’s Republic of China
| | - Meigui Wang
- School of Light Chemical Technology, Guangdong Industry Technical College, Guangzhou, People’s Republic of China
| | - Lixuan Wu
- School of Light Chemical Technology, Guangdong Industry Technical College, Guangzhou, People’s Republic of China
| | - Ping Kong
- School of Light Chemical Technology, Guangdong Industry Technical College, Guangzhou, People’s Republic of China
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7
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Guo A, Li H, Xu J, Li J, Li F. Effect of microstructure on the properties of polystyrene microporous foaming material. E-POLYMERS 2020. [DOI: 10.1515/epoly-2020-0012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The performance of Polystyrene microporous foaming (PS-MCF) materials is influenced by their microstructures. Therefore, it is essential for industrializing them to investigate the relationship between their microstructure and material properties. In this study, the relationship between the microstructure, compressive property, and thermal conductivity of the PS-MCF materials was studied systematically. The results show that the ideal foaming pressure of PS-MCF materials, obtaining compression performance, is around 20 MPa. In addition, the increase of temperature causes the decrease of sample density. It effects that the compression modulus and strength increase with the decrease of foaming temperature. Because the expansion rate and cell diameter of the PS-MCF materials reduce the thickness of cell wall, they are also negatively correlated with their mechanical properties. Moreover, there is a negative linear correlation between the thermal conductivity and cell rate, whereas the cell diameter is positively correlated with the thermal conductivity.
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Affiliation(s)
- Anfu Guo
- School of Mechanical and Automobile Engineering , Liaocheng University , Liaocheng 252059 , China
| | - Hui Li
- School of Mechanical and Automobile Engineering , Liaocheng University , Liaocheng 252059 , China
| | - Jie Xu
- School of Mechanical Engineering , Shandong University , Jinan 250061 , China
| | - Jianfeng Li
- School of Mechanical Engineering , Shandong University , Jinan 250061 , China
| | - Fangyi Li
- School of Mechanical Engineering , Shandong University , Jinan 250061 , China
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8
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Jeong EJ, Park CK, Kim SH. Fabrication of microcellular polylactide/modified silica nanocomposite foams. J Appl Polym Sci 2019. [DOI: 10.1002/app.48616] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Eun Jin Jeong
- Department of Organic and Nano Engineering, College of EngineeringHanyang University, 222 Wangsimni‐ro, Seongdong‐gu Seoul 04763 Korea
| | - Chang Kyu Park
- Department of Organic and Nano Engineering, College of EngineeringHanyang University, 222 Wangsimni‐ro, Seongdong‐gu Seoul 04763 Korea
| | - Seong Hun Kim
- Department of Organic and Nano Engineering, College of EngineeringHanyang University, 222 Wangsimni‐ro, Seongdong‐gu Seoul 04763 Korea
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9
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Amini Moghaddam M, Stloukal P, Kucharczyk P, Tow‐Swiatek A, Garbacz T, Pummerova M, Klepka T, Sedlařík V. Microcellular antibacterial polylactide‐based systems prepared by additive extrusion with ALUM. POLYM ADVAN TECHNOL 2019. [DOI: 10.1002/pat.4643] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Maliheh Amini Moghaddam
- Centre of Polymer Systems, University InstituteTomas Bata University in Zlin tr. Tomase Bati 5678 Zlin 760 01 Czech Republic
| | - Petr Stloukal
- Centre of Polymer Systems, University InstituteTomas Bata University in Zlin tr. Tomase Bati 5678 Zlin 760 01 Czech Republic
| | - Pavel Kucharczyk
- Centre of Polymer Systems, University InstituteTomas Bata University in Zlin tr. Tomase Bati 5678 Zlin 760 01 Czech Republic
| | - Aneta Tow‐Swiatek
- Faculty of Mechanical Engineering, Department of Technology and Polymer ProcessingLublin University of Technology ul. Nadbystrzycka 36D Lublin 20‐618 Poland
| | - Tomasz Garbacz
- Faculty of Mechanical Engineering, Department of Technology and Polymer ProcessingLublin University of Technology ul. Nadbystrzycka 36D Lublin 20‐618 Poland
| | - Martina Pummerova
- Centre of Polymer Systems, University InstituteTomas Bata University in Zlin tr. Tomase Bati 5678 Zlin 760 01 Czech Republic
| | - Tomasz Klepka
- Faculty of Mechanical Engineering, Department of Technology and Polymer ProcessingLublin University of Technology ul. Nadbystrzycka 36D Lublin 20‐618 Poland
| | - Vladimír Sedlařík
- Centre of Polymer Systems, University InstituteTomas Bata University in Zlin tr. Tomase Bati 5678 Zlin 760 01 Czech Republic
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Ge C, Wang S, Zhai W. Influence of cell type and skin-core structure on the tensile elasticity of the microcellular thermoplastic polyurethane foam. J CELL PLAST 2019. [DOI: 10.1177/0021955x19864381] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In this work, the foaming process was employed to achieve lightweight thermoplastic polyurethane materials, and then the hysteresis and residual strain of corresponding materials in the tensile process were quantitatively calculated. In order to study the deformed mechanism, the influences of cell type and skin-core structure on the tensile elasticity of thermoplastic polyurethane foam were investigated. The open-cell thermoplastic polyurethane foam exhibited much lower hysteresis and residual strain compared to thermoplastic polyurethane film without cell structure, which demonstrated that the open-cell structure benefited to the tensile elasticity. In the case of closed-cell thermoplastic polyurethane foam, it had lower hysteresis and residual strain than thermoplastic polyurethane film; however, higher value than the thermoplastic polyurethane film can be observed beyond 100% strain, resulting from the stress concentration in the skin-core structure. Consequently, the hysteresis phenomenon can be improved by adjusting the ratio of skin-core structure. Moreover, the influence of density on the elasticity of the open-cell thermoplastic polyurethane foam was also discussed in this study.
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Affiliation(s)
- Chengbiao Ge
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shiping Wang
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province, China
| | - Wentao Zhai
- School of Materials Science and Engineering, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
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Xu LQ, Huang HX. Tuning cell structure and expansion ratio of thick-walled biodegradable poly(lactic acid) foams prepared using supercritical CO2. J CELL PLAST 2019. [DOI: 10.1177/0021955x19864389] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Thick-walled poly(lactic acid) samples are foamed using supercritical carbon dioxide as physical foaming agent over a wide saturation time range using a constant-temperature mode and a wide foaming pressure range using the constant-temperature mode and a varying-temperature mode. Using the constant-temperature mode, three regions with no-celled core and two regions with cells of different diameters appear on the fractured surfaces of the foamed samples prepared at 5 and 10 min saturation times, respectively, whereas a relatively uniform cellular structure is obtained at 20–180 min saturation times. Raising the foaming pressure can improve the cellular structure uniformity. Moreover, prolonging saturation time or raising foaming pressure results in rupture of more cell walls and so formation of open-celled structure to a certain extent. Using the varying-temperature mode, a bimodal cellular structure with stamen-like cells and a trimodal cellular structure with an extraordinarily high expansion ratio (76.2) are successively achieved during raising the foaming pressure (18–22 MPa). The formation mechanisms for the bimodal and trimodal cellular structures are analyzed based on the result of the foaming pressure effect on the cellular structure in the foamed poly(lactic acid) samples prepared using the constant-temperature mode.
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Affiliation(s)
- Lin-Qiong Xu
- Lab for Micro Molding and Polymer Rheology, Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou, China
| | - Han-Xiong Huang
- Lab for Micro Molding and Polymer Rheology, Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou, China
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12
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Iesavand H, Rahmati M, Afzali D, Modiri S. Investigation on absorption and release of mercaptopurine anticancer drug from modified polylactic acid as polymer carrier by molecular dynamic simulation. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 105:110010. [PMID: 31546426 DOI: 10.1016/j.msec.2019.110010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 06/10/2019] [Accepted: 07/22/2019] [Indexed: 11/17/2022]
Abstract
The absorption and release of 6-mercaptopurine anticancer drug was investigated in biodegradable and biocompatible polymer of polylactic acid (PLA) using molecular dynamics simulation. For this purpose, the amount of mixing energy, radius of gyration, mean squared displacement and radial distribution function were computed and compared in concentrations of 5-36 wt% of 6-mercaptopurine drug. The simulation results show that increasing the concentration of the drug reduces mixing energy and PLA polymer carrier is able to carry 35.8 wt% of 6-mercaptopurine anticancer drug. Based on these results, the amount of 6-mercaptopurine release from PLA carrier 35.8 wt% of it in water environment is zero due to hydrophobic property of PLA and 6-mercaptopurine. Finally, polyethylene glycol (PEG) polymer with different percentages (10-30 wt%) was used to modify PLA carrier. The simulation results show that the rate of drug release increases by increasing the concentration of PEG polymer in the modified PLA carrier and also with increasing the percentage of drug loaded in the carrier and also the optimum weight percentage of PEG in modified PLA carrier for 35.8 wt% of drug concentration is 11 wt% and the rate of drug release is slower and equal to 4.4 molecules/ns.
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Affiliation(s)
- Homa Iesavand
- Department of Chemical Engineering, Graduate University of Advanced Technology, Kerman, Iran
| | - Mahmoud Rahmati
- Department of Chemical Engineering, Graduate University of Advanced Technology, Kerman, Iran.
| | - Dariush Afzali
- Department of Environment, Institute of Science and High Technology and Environmental Sciences, Kerman, Iran
| | - Sina Modiri
- Department of Chemical Engineering, Graduate University of Advanced Technology, Kerman, Iran
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Standau T, Zhao C, Murillo Castellón S, Bonten C, Altstädt V. Chemical Modification and Foam Processing of Polylactide (PLA). Polymers (Basel) 2019; 11:E306. [PMID: 30960290 PMCID: PMC6419231 DOI: 10.3390/polym11020306] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/06/2019] [Accepted: 02/07/2019] [Indexed: 11/16/2022] Open
Abstract
Polylactide (PLA) is known as one of the most promising biopolymers as it is derived from renewable feedstock and can be biodegraded. During the last two decades, it moved more and more into the focus of scientific research and industrial use. It is even considered as a suitable replacement for standard petroleum-based polymers, such as polystyrene (PS), which can be found in a wide range of applications-amongst others in foams for packaging and insulation applications-but cause strong environmental issues. PLA has comparable mechanical properties to PS. However, the lack of melt strength is often referred to as a drawback for most foaming processes. One way to overcome this issue is the incorporation of chemical modifiers which can induce chain extension, branching, or cross-linking. As such, a wide variety of substances were studied in the literature. This work should give an overview of the most commonly used chemical modifiers and their effects on rheological, thermal, and foaming behavior. Therefore, this review article summarizes the research conducted on neat and chemically modified PLA foamed with the conventional foaming methods (i.e., batch foaming, foam extrusion, foam injection molding, and bead foaming).
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Affiliation(s)
- Tobias Standau
- Depatment of Polymer Engineering, University Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
| | - Chunjing Zhao
- Depatment of Polymer Engineering, University Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
| | - Svenja Murillo Castellón
- Institut für Kunststofftechnik, University of Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart, Germany.
| | - Christian Bonten
- Institut für Kunststofftechnik, University of Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart, Germany.
| | - Volker Altstädt
- Depatment of Polymer Engineering, University Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
- Bavarian Polymer Institute and Bayreuth Institute of Macromolecular Research, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
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14
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Kwon DE, Park BK, Lee YW. Solid-State Foaming of Acrylonitrile-Butadiene-Styrene/Recycled Polyethylene Terephthalate Using Carbon Dioxide as a Blowing Agent. Polymers (Basel) 2019; 11:E291. [PMID: 30960276 PMCID: PMC6419198 DOI: 10.3390/polym11020291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 01/31/2019] [Accepted: 02/01/2019] [Indexed: 12/04/2022] Open
Abstract
In this study, a single paragraph of acrylonitrile-butadiene-styrene (ABS)/recycled polyethylene terephthalate (R-PET) polymeric foams is prepared using CO₂ as a blowing agent. First, the sorption kinetics of subcritical and supercritical CO₂ are first studied at saturation temperatures from -20 to 40 °C and a pressure of 10 MPa, in order to estimate the diffusion coefficient and the sorption amount. As the sorption temperature increases, the diffusion coefficient of CO₂ increases while the sorption amount decreases. Then, a series of two-step solid-state foaming experiments are conducted. In this process, a specimen is saturated with liquid CO₂ and foamed by dipping the sample in a high-temperature medium at 60 to 120 °C. The effects of foaming temperature and depressurization rate on the morphology and structure of ABS/R-PET microcellular foams are examined. The mean cell size and the variation of the cell size distribution increases as the foaming temperature and the depressurization rate increases.
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Affiliation(s)
- Dong Eui Kwon
- School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, 1 Gwananak-ro, Gwanak-gu, Seoul 151-744, Korea.
| | - Byung Kyu Park
- Research Institute of Advanced Materials, Seoul National University, 1 Gwananak-ro, Gwanak-gu, Seoul 151-744, Korea.
| | - Youn-Woo Lee
- School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, 1 Gwananak-ro, Gwanak-gu, Seoul 151-744, Korea.
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15
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Liu Y, Matuana LM. Surface texture and barrier performance of poly(lactic acid)-cellulose nanocrystal extruded-cast films. J Appl Polym Sci 2019. [DOI: 10.1002/app.47594] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Yuzhu Liu
- School of Packaging; Michigan State University; East Lansing Michigan 48824
| | - Laurent M. Matuana
- School of Packaging; Michigan State University; East Lansing Michigan 48824
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16
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Ludwiczak J, Frąckowiak S, Łużny R. Effect of Recycling on the Cellular Structure of Polylactide in a Batch Process. CELLULAR POLYMERS 2018. [DOI: 10.1177/026248931803700202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of the work is to demonstrate the possibility of using recycled biodegradable material as a cellular material with a reduced weight. An experimental study on the influence of recycling on the properties and foam ability of polylactide (PLA) was carried out. The influence of recycling on the polymer crystallinity, thermal and viscoelastic properties was investigated. During the batch process the cellular structure in PLA and recycled PLA were created. A higher degree of crystallinity, a lower viscosity value and a lower melt strength for recycled PLA, as compared to original material, were observed. For the recycled PLA, a fine cellular structure and low density (0.60 g/cm3) were obtained.
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Affiliation(s)
- Joanna Ludwiczak
- Faculty of Environmental Engineering, Wrocław University of Science and Technology, 27 Wybrzeże Wyspiańskiego st., 50-370 Wrocław, Poland
| | - Stanisław Frąckowiak
- Faculty of Environmental Engineering, Wrocław University of Science and Technology, 27 Wybrzeże Wyspiańskiego st., 50-370 Wrocław, Poland
| | - Rafał Łużny
- Department of Chemistry, Wrocław University of Science and Technology, 7/9 Gdańska st., 50-344 Wrocław, Poland
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17
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Experimental measurement of CO2 diffusion in PMMA and its effect on microcellular foaming. J Supercrit Fluids 2018. [DOI: 10.1016/j.supflu.2018.01.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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18
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Mahdavi M, Yousefzade O, Garmabi H. A simple method for preparation of microcellular PLA/calcium carbonate nanocomposite using super critical nitrogen as a blowing agent: Control of microstructure. ADVANCES IN POLYMER TECHNOLOGY 2018. [DOI: 10.1002/adv.21972] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Mina Mahdavi
- Department of Chemical Engineering; The University of Mississippi; Mississippi
| | - Omid Yousefzade
- Department of Polymer Engineering and Color Technology; Amirkabir University of Technology; Tehran Iran
| | - Hamid Garmabi
- Department of Polymer Engineering and Color Technology; Amirkabir University of Technology; Tehran Iran
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19
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Xu LQ, Zhao YQ. Preparation, Foaming and Characterization of Poly(l-lactic acid))/Poly(d-lactic acid)-Grafted Graphite Oxide Blends. INT POLYM PROC 2018. [DOI: 10.3139/217.3492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Commercial poly(l-lactic acid) (PLLA) was blended with different contents of graphene oxide-graft-poly(d-lactic acid) (GO-g-PDLA), which was synthesized via ring-opening polymerization using modified GO as initiator. PLLA and PLLA/GO-g-PDLA blend foams were prepared in a batch process via varying-temperature mode using supercritical carbon dioxide as physical foaming agent. The results showed that the addition of GO-g-PDLA in PLLA leads to the formation of stereocomplex (sc)-crystallites. Increase in the GO-g-PDLA content enhances the IR absorption, diffraction peak and melting peak corresponding to the sc-crystallites. The addition of GO-g-PDLA to PLLA leads to the decrease of the cell diameter, increase of the cell density and to a little change in expansion ratio, which is attributed to the fact that the enhancement of PLLA crystallization restricts cell growth and GO-g-PDLA acts as nucleation point.
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Affiliation(s)
- L. Q. Xu
- The Key Laboratory of Polymer Processing Engineering of Ministry of Education , South China University of Technology, Guangzhou, Guangdong , PRC
- School of Materials Science and Chemical Engineering , Ningbo University, Ningbo, Zhejiang , PRC
| | - Y. Q. Zhao
- The Key Laboratory of Polymer Processing Engineering of Ministry of Education , South China University of Technology, Guangzhou, Guangdong , PRC
- Ningbo Key Lab of Polymer Materials , Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang , PRC
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20
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Microcellular foaming of arabinoxylan and PEGylated arabinoxylan with supercritical CO2. Carbohydr Polym 2018; 181:442-449. [DOI: 10.1016/j.carbpol.2017.09.068] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/21/2017] [Accepted: 09/22/2017] [Indexed: 11/18/2022]
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21
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Zhang X, Ding W, Zhao N, Chen J, Park CB. Effects of Compressed CO2 and Cotton Fibers on the Crystallization and Foaming Behaviors of Polylactide. Ind Eng Chem Res 2018. [DOI: 10.1021/acs.iecr.7b04139] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiaoli Zhang
- School
of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
- Microcellular
Plastics Manufacturing Laboratory, Department of Mechanical and Industrial
Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Weidan Ding
- Microcellular
Plastics Manufacturing Laboratory, Department of Mechanical and Industrial
Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Na Zhao
- School
of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
- Microcellular
Plastics Manufacturing Laboratory, Department of Mechanical and Industrial
Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Jingbo Chen
- School
of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Chul B. Park
- Microcellular
Plastics Manufacturing Laboratory, Department of Mechanical and Industrial
Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
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22
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Role of high-density polyethylene in the crystallization behaviors, rheological property, and supercritical CO2 foaming of poly (lactic acid). Polym Degrad Stab 2017. [DOI: 10.1016/j.polymdegradstab.2017.11.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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23
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Jamalpour S, Ghaffarian SR, Goldansaz H. Using supramolecular associations to create stable cellular structures in amorphous soft polymers. POLYM ADVAN TECHNOL 2017. [DOI: 10.1002/pat.4210] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Seifollah Jamalpour
- Department of Polymer Engineering; Amirkabir University of Technology; Tehran Iran
| | | | - Hadi Goldansaz
- Department of Polymer Engineering; Amirkabir University of Technology; Tehran Iran
- Bio and Soft Matter Division (BSMA), Institut de la Matière Condensée et des Nanosciences (IMCN), Université catholique de Louvain; Louvain-la-Neuve Belgium
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24
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Wang Y, Song Y, Du J, Xi Z, Wang Q. Preparation of Desirable Porous Cell Structure Polylactide/Wood Flour Composite Foams Assisted by Chain Extender. MATERIALS 2017; 10:ma10090999. [PMID: 28846604 PMCID: PMC5615654 DOI: 10.3390/ma10090999] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 08/23/2017] [Accepted: 08/23/2017] [Indexed: 11/16/2022]
Abstract
Polylactide (PLA)/wood flour composite foam were prepared through a batch foaming process. The effect of the chain extender on the crystallization behavior and dynamic rheological properties of the PLA/wood flour composites were investigated as well as the crystal structure and cell morphology of the composite foams. The incorporation of the chain extender enhanced the complex viscosity and storage modulus of PLA/wood flour composites, indicating the improved melt elasticity. The chain extender also led to a decreased crystallization rate and final crystallinity of PLA/wood flour composites. With an increasing chain extender content, a finer and more uniform cell structure was formed, and the expansion ratio of PLA/wood flour composite foams was much higher than without the chain extender. Compared to the unfoamed composites, the crystallinity of the foamed PLA/wood flour composites was improved and the crystal was loosely packed. However, the new crystalline form was not evident.
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Affiliation(s)
- Youyong Wang
- Key Laboratory of Bio-Based Material Science and Technology (Ministry of Education), Northeast Forestry University, Harbin 150040, China.
| | - Yongming Song
- Key Laboratory of Bio-Based Material Science and Technology (Ministry of Education), Northeast Forestry University, Harbin 150040, China.
| | - Jun Du
- Key Laboratory of Bio-Based Material Science and Technology (Ministry of Education), Northeast Forestry University, Harbin 150040, China.
| | - Zhenhao Xi
- State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Qingwen Wang
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
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25
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Karkhanis SS, Stark NM, Sabo RC, Matuana LM. Blown film extrusion of poly(lactic acid) without melt strength enhancers. J Appl Polym Sci 2017. [DOI: 10.1002/app.45212] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Sonal S. Karkhanis
- School of Packaging; Michigan State University; East Lansing Michigan 48824
| | - Nicole M. Stark
- U.S. Department of Agriculture, Forest Service; Forest Products Laboratory; One Gifford Pinchot Drive Madison Wisconsin 53726
| | - Ronald C. Sabo
- U.S. Department of Agriculture, Forest Service; Forest Products Laboratory; One Gifford Pinchot Drive Madison Wisconsin 53726
| | - Laurent M. Matuana
- School of Packaging; Michigan State University; East Lansing Michigan 48824
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26
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Punet X, Levato R, Bataille I, Letourneur D, Engel E, Mateos-Timoneda MA. Polylactic acid organogel as versatile scaffolding technique. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.02.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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27
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Farah S, Anderson DG, Langer R. Physical and mechanical properties of PLA, and their functions in widespread applications - A comprehensive review. Adv Drug Deliv Rev 2016; 107:367-392. [PMID: 27356150 DOI: 10.1016/j.addr.2016.06.012] [Citation(s) in RCA: 1036] [Impact Index Per Article: 129.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 06/16/2016] [Accepted: 06/17/2016] [Indexed: 12/28/2022]
Abstract
Poly(lactic acid) (PLA), so far, is the most extensively researched and utilized biodegradable aliphatic polyester in human history. Due to its merits, PLA is a leading biomaterial for numerous applications in medicine as well as in industry replacing conventional petrochemical-based polymers. The main purpose of this review is to elaborate the mechanical and physical properties that affect its stability, processability, degradation, PLA-other polymers immiscibility, aging and recyclability, and therefore its potential suitability to fulfill specific application requirements. This review also summarizes variations in these properties during PLA processing (i.e. thermal degradation and recyclability), biodegradation, packaging and sterilization, and aging (i.e. weathering and hygrothermal). In addition, we discuss up-to-date strategies for PLA properties improvements including components and plasticizer blending, nucleation agent addition, and PLA modifications and nanoformulations. Incorporating better understanding of the role of these properties with available improvement strategies is the key for successful utilization of PLA and its copolymers/composites/blends to maximize their fit with worldwide application needs.
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28
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Forghani E, Azizi H, Karabi M, Ghasemi I. Compatibility, morphology and mechanical properties of polylactic acid/polyolefin elastomer foams. J CELL PLAST 2016. [DOI: 10.1177/0021955x16681450] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this study, different blends based on polylactic acid (PLA)/polyolefin elastomer (POE) and compatibilized PLA/POE was prepared by melt mixing. The compatibilizer glycidyl methacrylate-grafted-polyolefin elastomer (POE-g-GMA) was synthesized in a separate process. The Fourier transform infrared spectrum confirmed the reaction of POE and glycidyl methacrylate. Meanwhile, the morphology of dispersed phase was observed by scanning electron microscope. The results indicated that the compatibilizer has improved the compatibility and interfacial adhesion between PLA and POE phase. The rheological test results revealed that the introduction of compatibilizer could enhance the storage modulus and melt complex viscosity of PLA/POE blends. The foamability was studied in the presence of azodicarbonamide as a chemical blowing agent in the batch foaming process. Morphology of foams such as porous cell size, porous cell population density, and foam density were studied. It was found that the presence of POE in PLA foams has a great influence on their mechanical properties and the toughness. Addition of POE-g-GMA in samples increased elastic modulus of foams and decreased their strain at break.
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Affiliation(s)
- E Forghani
- Department of Plastic Processing, Iran Polymer and Petrochemical Institute, Tehran, Iran
| | - H Azizi
- Department of Plastic Processing, Iran Polymer and Petrochemical Institute, Tehran, Iran
| | - M Karabi
- Department of Elastomer Processing, Iran Polymer and Petrochemical Institute, Tehran, Iran
| | - I Ghasemi
- Department of Plastic Processing, Iran Polymer and Petrochemical Institute, Tehran, Iran
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29
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Ren Q, Wang J, Zhai W, Lee RE. Fundamental Influences of Induced Crystallization and Phase Separation on the Foaming Behavior of Poly(lactic acid)/Polyethylene Glycol Blends Blown with Compressed CO2. Ind Eng Chem Res 2016. [DOI: 10.1021/acs.iecr.6b03266] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Qian Ren
- Ningbo
Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China
| | - Jing Wang
- Ningbo
Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China
| | - Wentao Zhai
- Ningbo
Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China
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30
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Li R, Li L, Zeng D, Liu Q, Fang T. Numerical Selection of the Parameters in Producing Microcellular Polymethyl Methacrylate with Supercritical CO2. CELLULAR POLYMERS 2016. [DOI: 10.1177/026248931603500602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A systematized calculation of foaming parameters in producing microcellular polymethyl methacrylate (PMMA) with supercritical carbon dioxide (SCCO2) was proposed. The calculated optimal results were saturation temperature = 313 K, pressure = 25 MPa and time = 15 h, which were achieved by the Chow model, classical nucleation theory and Fick diffusion law, respectively. Additionally, the Center-Composite Design (CCD) statistical approach in Response Surface Method (RSM) was employed to evaluate the validity of the calculated parameters. The error between the optimal parameters predicted by CCD statistical approach and the calculated ones was acceptable, demonstrating the accuracy of the calculated parameters.
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Affiliation(s)
- Ruosong Li
- Department of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Lu Li
- Department of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Dan Zeng
- Department of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Qinli Liu
- Department of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Tao Fang
- Department of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, China
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31
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Huang A, Kharbas H, Ellingham T, Mi H, Turng LS, Peng X. Mechanical properties, crystallization characteristics, and foaming behavior of polytetrafluoroethylene-reinforced poly(lactic acid) composites. POLYM ENG SCI 2016. [DOI: 10.1002/pen.24454] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- An Huang
- National Engineering Research Center of Novel Equipment for Polymer Processing; South China University of Technology; Guangzhou 510640 China
- Polymer Engineering Center; University of Wisconsin-Madison; Madison Wisconsin 53706
| | - Hrishikesh Kharbas
- Polymer Engineering Center; University of Wisconsin-Madison; Madison Wisconsin 53706
| | - Thomas Ellingham
- Polymer Engineering Center; University of Wisconsin-Madison; Madison Wisconsin 53706
| | - Haoyang Mi
- National Engineering Research Center of Novel Equipment for Polymer Processing; South China University of Technology; Guangzhou 510640 China
- Polymer Engineering Center; University of Wisconsin-Madison; Madison Wisconsin 53706
| | - Lih-Sheng Turng
- Polymer Engineering Center; University of Wisconsin-Madison; Madison Wisconsin 53706
| | - Xiangfang Peng
- National Engineering Research Center of Novel Equipment for Polymer Processing; South China University of Technology; Guangzhou 510640 China
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32
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Xu Y, Delgado P, Todd AD, Loi J, Saba SA, McEneany RJ, Tower T, Topolkaraev V, Macosko CW, Hillmyer MA. Lightweight micro-cellular plastics from polylactide/polyolefin hybrids. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.08.102] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Zhang Y, Jiang T, Sheng B, Long Y, Gao C, Ma C, Xu P. Coexistence of two d-lactate-utilizing systems in Pseudomonas putida KT2440. ENVIRONMENTAL MICROBIOLOGY REPORTS 2016; 8:699-707. [PMID: 27264531 DOI: 10.1111/1758-2229.12429] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 05/13/2016] [Accepted: 05/24/2016] [Indexed: 06/05/2023]
Abstract
It is advantageous for rhizosphere-dwelling microorganisms to utilize organic acids such as lactate. Pseudomonas putida KT2440 is one of the most widely studied rhizosphere-dwelling model organisms. The P. putida KT2440 genome contains an NAD-dependent d-lactate dehydrogenase encoding gene, but mutation of this gene does not play a role in d-lactate utilization. Instead, it was found that d-lactate utilization in P. putida KT2440 proceeds via a multidomain NAD-independent d-lactate dehydrogenase with a C-terminal domain containing several Fe-S cluster-binding motifs (Fe-S d-iLDH) and glycolate oxidase, which is widely distributed in various microorganisms. Both Fe-S d-iLDH and glycolate oxidase were identified to be membrane-bound proteins. Neither Fe-S d-iLDH nor glycolate oxidase is constitutively expressed but both of them can be induced by either enantiomer of lactate in P. putida KT2440. This study shows a case in which an environmental microbe contains two types of enzymes specific for d-lactate utilization.
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Affiliation(s)
- Yingxin Zhang
- State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Tianyi Jiang
- State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101, People's Republic of China
| | - Binbin Sheng
- State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Yangdanyu Long
- State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Chao Gao
- State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Cuiqing Ma
- State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
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34
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Xue S, Jia P, Ren Q, Liu X, Lee RE, Zhai W. Improved expansion ratio and heat resistance of microcellular poly(L-lactide) foam via in-situ formation of stereocomplex crystallites. J CELL PLAST 2016. [DOI: 10.1177/0021955x16670587] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
It is critical to broaden the applications of poly(L-lactic acid) foams by improving heat resistance properties. The stereocomplex crystallites that are formed by melt blending of poly(L-lactic acid)/polylactide possess high melting point of about 220℃ and thus exhibit high heat resistance; therefore, the introduction of stereocomplex crystallites tends to improve the thermal stability of poly(lactic acid) foam. Unfortunately, using the solid-state foaming method, it was found that the expansion ratio of the obtained poly(lactic acid) foams was compromised with the value of 1.7 times once the stereocomplex crystallites were formed during the sample saturation stage. In this study, by applying a high compression molding temperature of 230℃, the as-prepared poly(L-lactic acid) and poly(L-lactic acid)/polylactide blends were amorphous. After being CO2 saturated at a mild condition, the specimens were foamed at 90–160℃. The wide-angle X-ray diffraction profiles presented that the stereocomplex crystallites and PLA homocrystals were in-situ generated during the foaming process. It is observed that the in-situ formed stereocomplex crystallites could act as the physical cross-linking agent to stabilize the nucleated bubbles and suppress cell coalescence, resulting in the increased expansion ratio (with value of about 23.6–25.6 times) and cell density, especially at high foaming temperatures and extended foaming time. Furthermore, the in-situ formed stereocomplex crystallites during the foaming increased the heat resistance performance of poly(L-lactic acid) foams. This novel crystallization control method helps us to find a balance point in preparing poly(L-lactic acid) foam with high expansion ratio, well-defined cell structure and high heat resistance performance.
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Affiliation(s)
- Shuaiwei Xue
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, China
- Faculty of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
| | - Pin Jia
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, China
| | - Qian Ren
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, China
| | - Xincai Liu
- Faculty of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
| | - Richard E Lee
- Macro Engineering and Technology Inc., Ontario, Canada
| | - Wentao Zhai
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, China
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35
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Wang K, Wang J, Zhao D, Zhai W. Preparation of microcellular poly(lactic acid) composites foams with improved flame retardancy. J CELL PLAST 2016. [DOI: 10.1177/0021955x16633644] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this study, flame-retardant poly(lactic acid) foams with satisfactory cell structures were prepared by microcellular foaming technology using phosphorus-containing flame retardant and graphene as the charring agent. The introduction of 5–30 wt% flame retardant increased the limited oxygen index value of poly(lactic acid) from 19.0 to 26.5–37.8% and simultaneously increased the foam expansion of poly(lactic acid) foams from 4.4 to 5.8–17.5. In addition, all the prepared poly(lactic acid)/flame-retardant composites passed the UL-94 V-0 rating. The addition of 0.5 wt% graphene increased the limited oxygen index value of poly(lactic acid)/flame-retardant composite with flame-retardant content of 15 wt% from 27.9 to 29.2%, and more graphene additions improved the antidripping behavior of poly(lactic acid) composites. The possible mechanisms of the effects of the resultant cellular structure on the flame-retardant properties of poly(lactic acid) composites were also discussed.
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Affiliation(s)
- Kun Wang
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province, China
| | - Jingjing Wang
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province, China
- Faculty of Material Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang Province, China
| | - Dan Zhao
- School of Chemical Engineering, Ningbo University of Technology, Ningbo, Zhejiang Province, China
| | - Wentao Zhai
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province, China
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36
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Mantaranon N, Chirachanchai S. Polyoxymethylene foam: From an investigation of key factors related to porous morphologies and microstructure to the optimization of foam properties. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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37
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Diethylene glycol monobutyl ether adipate as a novel plasticizer for biodegradable polylactide. Polym Bull (Berl) 2016. [DOI: 10.1007/s00289-016-1646-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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38
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Yuan Y, Hu Z, Fu X, Jiang L, Xiao Y, Hu K, Yan P, Lei J. Poly(lactic acid) plasticized by biodegradable glyceryl lactate. J Appl Polym Sci 2016. [DOI: 10.1002/app.43460] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ye Yuan
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
| | - Zeyu Hu
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
| | - Xiaowei Fu
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
| | - Liang Jiang
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
| | - Yao Xiao
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
| | - Kai Hu
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
| | - Peiyao Yan
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
| | - Jinxin Lei
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
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39
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Xing C, Matuana LM. Epoxidized soybean oil-plasticized poly(lactic acid) films performance as impacted by storage. J Appl Polym Sci 2015. [DOI: 10.1002/app.43201] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Cheng Xing
- School of Packaging; Michigan State University; East Lansing Michigan 48824
| | - Laurent M. Matuana
- School of Packaging; Michigan State University; East Lansing Michigan 48824
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40
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Yang Q, Zhang G, Ma Z, Li J, Fan X. Effects of processing parameters and thermal history on microcellular foaming behaviors of PEEK using supercritical CO2. J Appl Polym Sci 2015. [DOI: 10.1002/app.42576] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Quan Yang
- Department of Applied Chemistry; School of Science; Northwestern Polytechnical University; Xi'an 710072 China
| | - Guangcheng Zhang
- Department of Applied Chemistry; School of Science; Northwestern Polytechnical University; Xi'an 710072 China
| | - Zhonglei Ma
- Department of Applied Chemistry; School of Science; Northwestern Polytechnical University; Xi'an 710072 China
| | - Jiantong Li
- Department of Applied Chemistry; School of Science; Northwestern Polytechnical University; Xi'an 710072 China
| | - Xiaolong Fan
- Department of Applied Chemistry; School of Science; Northwestern Polytechnical University; Xi'an 710072 China
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41
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Julien J, Quantin JC, Bénézet JC, Bergeret A, Lacrampe M, Krawczak P. Chemical foaming extrusion of poly(lactic acid) with chain-extenders: Physical and morphological characterizations. Eur Polym J 2015. [DOI: 10.1016/j.eurpolymj.2015.03.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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42
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Notario B, Pinto J, Rodríguez-Pérez M. Towards a new generation of polymeric foams: PMMA nanocellular foams with enhanced physical properties. POLYMER 2015. [DOI: 10.1016/j.polymer.2015.03.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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43
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Chen BY, Jing X, Mi HY, Zhao H, Zhang WH, Peng XF, Turng LS. Fabrication of polylactic acid/polyethylene glycol (PLA/PEG) porous scaffold by supercritical CO2
foaming and particle leaching. POLYM ENG SCI 2015. [DOI: 10.1002/pen.24073] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Bin-Yi Chen
- The Key Laboratory of Polymer Processing Engineering of Ministry of Education; National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology; Guangzhou 510640 China
| | - Xin Jing
- The Key Laboratory of Polymer Processing Engineering of Ministry of Education; National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology; Guangzhou 510640 China
- Department of Mechanical Engineering; University of Wisconsin-Madison; Madison Wisconsin 53706
| | - Hao-Yang Mi
- The Key Laboratory of Polymer Processing Engineering of Ministry of Education; National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology; Guangzhou 510640 China
| | - Haibin Zhao
- The Key Laboratory of Polymer Processing Engineering of Ministry of Education; National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology; Guangzhou 510640 China
- School of Materials Science and Engineering, Shandong University; Jinan Shandong 250061 China
| | - Wen-Hao Zhang
- The Key Laboratory of Polymer Processing Engineering of Ministry of Education; National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology; Guangzhou 510640 China
| | - Xiang-Fang Peng
- The Key Laboratory of Polymer Processing Engineering of Ministry of Education; National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology; Guangzhou 510640 China
| | - Lih-Sheng Turng
- Department of Mechanical Engineering; University of Wisconsin-Madison; Madison Wisconsin 53706
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44
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Jia P, Hu J, Zhai W, Duan Y, Zhang J, Han C. Cell Morphology and Improved Heat Resistance of Microcellular Poly(l-lactide) Foam via Introducing Stereocomplex Crystallites of PLA. Ind Eng Chem Res 2015. [DOI: 10.1021/ie504345y] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Pin Jia
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao 266042, Shandong, China
- Ningbo
Key Lab of Polymer Materials, Ningbo Institute of Material Technology
and Engineering, Chinese Academy of Sciences, Ningbo 315201, Zhejiang Province, China
| | - Jie Hu
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao 266042, Shandong, China
| | - Wentao Zhai
- Ningbo
Key Lab of Polymer Materials, Ningbo Institute of Material Technology
and Engineering, Chinese Academy of Sciences, Ningbo 315201, Zhejiang Province, China
| | - Yongxin Duan
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao 266042, Shandong, China
| | - Jianming Zhang
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao 266042, Shandong, China
| | - Changyu Han
- Key
Laboratory of Polymer Ecomaterials, Changchun Institute of Applied
Chemistry, Chinese Academy of Sciences, Changchun 130022, China
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45
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Li R, Zeng D, Pan Q, Fang T. Response surface optimization for producing microcellular polymethyl methacrylate foam using supercritical CO2. J CELL PLAST 2015. [DOI: 10.1177/0021955x14566206] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A regression model constructed by response surface methodology was employed to optimize the relationships between the cell density of microcellular polymethyl methacrylate foam and three independent variables: foaming pressure, temperature, and time. A Box–Behnken Design statistical approach was employed to fit the available response data to a second-order polynomial response surface model. The analysis of variance of the model indicated that the interactions between the foaming pressure and temperature, and that between the foaming temperature and the saturation time, both positively affect the cell density. Experimental verification of the predicted optimum conditions of foaming pressure = 21 MPa, foaming temperature = 313 K, and saturation time = 6.9 h gave an actual maximum cell density of 20.86 × 109 cells/cm3, which is close to the data predicted by the regression model.
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Affiliation(s)
- Ruosong Li
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an, China
| | - Dan Zeng
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an, China
| | - Qi Pan
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an, China
| | - Tao Fang
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an, China
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46
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Gao D, Wang JP, Wang Y, Zhang P. Effect of melt viscosity on the cell morphology and properties of poly(lactic acid) foams. J CELL PLAST 2014. [DOI: 10.1177/0021955x14566210] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A compression molding foaming technique was used to prepare polylactic acid foams with a chemical foaming agent. The effect of melt viscosity of the polylactic acid on its cell morphology, apparent density, void fraction, cell population density, cell diameter, mechanical properties, and thermal property were studied. The apparent density of the foamed polylactic acid first decreased with decreasing melt viscosity and then increased, whereas the void fraction showed an opposite trend. A lower melt viscosity resulted in smaller cells, a more uniform cell size distribution, and a higher cell population density until the viscosity could not support further cell expansion which subsequently could cause gas escape and cell collapse. The tensile strength of the foams first increased with decreasing melt viscosity and then decreased. Their impact strength and flexural strength were improved by decreasing the melt viscosity. The use of glycidyl methacrylate only showed a small influence on the thermal stability of foamed polylactic acid.
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Affiliation(s)
- De Gao
- Department of Biosystems Engineering, Zhejiang University, Hangzhou, China
- Ningbo Institute of technology, Zhejiang University, Ningbo, China
| | - Jian-ping Wang
- Department of Biosystems Engineering, Zhejiang University, Hangzhou, China
| | - Yu Wang
- Department of Biosystems Engineering, Zhejiang University, Hangzhou, China
| | - Ping Zhang
- Ningbo Institute of technology, Zhejiang University, Ningbo, China
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47
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48
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Wang Y, Lv M, Zhang Y, Xiao X, Jiang T, Zhang W, Hu C, Gao C, Ma C, Xu P. Reconstruction of lactate utilization system in Pseudomonas putida KT2440: a novel biocatalyst for l-2-hydroxy-carboxylate production. Sci Rep 2014; 4:6939. [PMID: 25373400 PMCID: PMC4221787 DOI: 10.1038/srep06939] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 10/20/2014] [Indexed: 11/09/2022] Open
Abstract
As an important method for building blocks synthesis, whole cell biocatalysis is hindered by some shortcomings such as unpredictability of reactions, utilization of opportunistic pathogen, and side reactions. Due to its biological and extensively studied genetic background, Pseudomonas putida KT2440 is viewed as a promising host for construction of efficient biocatalysts. After analysis and reconstruction of the lactate utilization system in the P. putida strain, a novel biocatalyst that only exhibited NAD-independent D-lactate dehydrogenase activity was prepared and used in L-2-hydroxy-carboxylates production. Since the side reaction catalyzed by the NAD-independent L-lactate dehydrogenase was eliminated in whole cells of recombinant P. putida KT2440, two important L-2-hydroxy-carboxylates (L-lactate and L-2-hydroxybutyrate) were produced in high yield and high optical purity by kinetic resolution of racemic 2-hydroxy carboxylic acids. The results highlight the promise in biocatalysis by the biotechnologically important organism P. putida KT2440 through genomic analysis and recombination.
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Affiliation(s)
- Yujiao Wang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Min Lv
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Yingxin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Xieyue Xiao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Tianyi Jiang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Wen Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Chunhui Hu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Chao Gao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Cuiqing Ma
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Ping Xu
- 1] State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China [2] State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
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49
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Mechanical and dielectric properties of microcellular polycarbonate foams with unimodal or bimodal cell-size distributions. J CELL PLAST 2014. [DOI: 10.1177/0021955x14542989] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This article reports on the compressive, dynamic mechanical and dielectric properties of microcellular polycarbonate foams with unimodal or bimodal cell-size distributions fabricated using the environment-friendly supercritical carbon dioxide. The effects of cell morphologies such as relative density, cell-size distribution and porosity on the compressive strength, Young’s modulus, storage modulus, loss modulus, dielectric constant and loss tangent of the microcellular polycarbonate foams are investigated quantitatively. Experimental values of the compressive strength and Young’s modulus fit very well with the theoretical values calculated from the Gibson–Ashby model at low relative densities. The higher relative density leads to higher storage modulus and loss modulus. The bimodal foams significantly improve the compressive and dynamic mechanical properties compared to the unimodal foams with the same relative density. The dielectric properties of microcellular foams depend only on the total porosity, but not on the cell-size distribution or microstructure of the foams. With increasing porosity, the dielectric constant of the microcellular foams gradually decreases, and agrees very well with the curve calculated from the Maxwell-Garnett-spheres model.
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50
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Investigation of thermodynamic properties of the binary system polyethylene glycol/CO2 using new methods. J Supercrit Fluids 2014. [DOI: 10.1016/j.supflu.2013.12.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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