1
|
Zhang Z, Cui S, Ma R, Ye Q, Sun J, Wang Y, Liu C, Wang Z. Melt stretching and quenching produce low-crystalline biodegradable poly(lactic acid) filled with β-form shish for highly improved mechanical toughness. Int J Biol Macromol 2023; 251:126220. [PMID: 37572805 DOI: 10.1016/j.ijbiomac.2023.126220] [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: 05/08/2023] [Revised: 06/27/2023] [Accepted: 08/05/2023] [Indexed: 08/14/2023]
Abstract
High-toughness biodegradable poly(lactic acid) (PLA) has always been intensively pursued on the way of replacing traditional petroleum-based plastics. Regulating microstructures to achieve self-toughening holds great promise due to avoidance of incorporating other heterogeneous components. Herein, we propose a straightforward and effective way to tailor microstructures and properties of PLA through melt-stretching and quenching of slightly crosslinked samples. The melt stretching drives chains orientation and crystallization at high temperature, while the quenching followed can freeze the crystallization process to any stage. For the first time, we prepare a type of transparent and low-crystalline PLA filled with rod-like β-form shish, which displays an outstanding tensile toughness, almost 17 times that of the conventional technique-processed one. This mechanical superiority is enabled by an integration of high ductility due to oriented chain network, and high tensile stress endowed by nanofibrous filler's role of β-form shish. Furthermore, the mechanically toughened PLA is demonstrated to generate the richest micro-cracks and shear bands under loading, which can effectively dissipate the deformational energy and underlie the high toughness. This work opens a new prospect for the bottom-up design of high-performance bio-based PLA materials that are tough, ductile and transparent by precise microstructural regulation through scalable melt processing route.
Collapse
Affiliation(s)
- Zhen Zhang
- National Engineering Research Center for Advanced Polymer Processing Technology, Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, Zhengzhou University, Zhengzhou 450002, China
| | - Shanlin Cui
- National Engineering Research Center for Advanced Polymer Processing Technology, Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, Zhengzhou University, Zhengzhou 450002, China
| | - Ruixue Ma
- National Engineering Research Center for Advanced Polymer Processing Technology, Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, Zhengzhou University, Zhengzhou 450002, China
| | - Qiuyang Ye
- National Engineering Research Center for Advanced Polymer Processing Technology, Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, Zhengzhou University, Zhengzhou 450002, China
| | - Jiahui Sun
- National Engineering Research Center for Advanced Polymer Processing Technology, Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, Zhengzhou University, Zhengzhou 450002, China
| | - Yaming Wang
- National Engineering Research Center for Advanced Polymer Processing Technology, Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, Zhengzhou University, Zhengzhou 450002, China.
| | - Chuntai Liu
- National Engineering Research Center for Advanced Polymer Processing Technology, Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, Zhengzhou University, Zhengzhou 450002, China
| | - Zhen Wang
- National Engineering Research Center for Advanced Polymer Processing Technology, Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, Zhengzhou University, Zhengzhou 450002, China.
| |
Collapse
|
2
|
Anstey A, Tuccitto AV, Lee PC, Park CB. Generation of Tough, Stiff Polylactide Nanocomposites through the In Situ Nanofibrillation of Thermoplastic Elastomer. ACS APPLIED MATERIALS & INTERFACES 2022; 14:14422-14434. [PMID: 35302743 DOI: 10.1021/acsami.1c13836] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Polylactide (PLA) resins are among the most desirable biopolymers due to their biobased and compostable nature, excellent stiffness, and tensile strength. However, the widespread application of PLA has long been hindered by its inherent brittleness. While multiple routes have been successfully developed for the toughening of PLA, this toughening has always come at the cost of compromising the stiffness and strength of the matrix. In this work, we report a robust and scalable method for the development of PLA nanocomposites with an unprecedented combination of stiffness and toughness. Using the in situ nanofibrillation technique, we generated PLA composites containing nanofibrils of thermoplastic polyester elastomer (TPEE). Due to the high aspect ratio of these nanofibrils, they form physically percolated networks at low weight fractions (∼2.8 wt %) which dramatically change the mechanical behavior of the material. We found that, upon network formation, the material transitions from brittle to ductile behavior, dramatically increasing its toughness with only a marginal decrease in Young's modulus. We investigate the peculiar rheological behavior and crystallization kinetics of these blends, and propose an extension of the critical ligament thickness mechanism, wherein intrinsic toughening arises at the fiber-matrix interface in the presence of entangled elastomer networks.
Collapse
Affiliation(s)
- Andrew Anstey
- Microcellular Plastics Manufacturing Laboratory (MPML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto M5S 3G8, Canada
- Multifunctional Composites Manufacturing Laboratory (MCML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto M5S 3G8, Canada
| | - Anthony V Tuccitto
- Multifunctional Composites Manufacturing Laboratory (MCML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto M5S 3G8, Canada
| | - Patrick C Lee
- Microcellular Plastics Manufacturing Laboratory (MPML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto M5S 3G8, Canada
- Multifunctional Composites Manufacturing Laboratory (MCML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto M5S 3G8, Canada
| | - Chul B Park
- Microcellular Plastics Manufacturing Laboratory (MPML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto M5S 3G8, Canada
| |
Collapse
|
3
|
Bonferoni MC, Caramella C, Catenacci L, Conti B, Dorati R, Ferrari F, Genta I, Modena T, Perteghella S, Rossi S, Sandri G, Sorrenti M, Torre ML, Tripodo G. Biomaterials for Soft Tissue Repair and Regeneration: A Focus on Italian Research in the Field. Pharmaceutics 2021; 13:pharmaceutics13091341. [PMID: 34575417 PMCID: PMC8471088 DOI: 10.3390/pharmaceutics13091341] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 12/22/2022] Open
Abstract
Tissue repair and regeneration is an interdisciplinary field focusing on developing bioactive substitutes aimed at restoring pristine functions of damaged, diseased tissues. Biomaterials, intended as those materials compatible with living tissues after in vivo administration, play a pivotal role in this area and they have been successfully studied and developed for several years. Namely, the researches focus on improving bio-inert biomaterials that well integrate in living tissues with no or minimal tissue response, or bioactive materials that influence biological response, stimulating new tissue re-growth. This review aims to gather and introduce, in the context of Italian scientific community, cutting-edge advancements in biomaterial science applied to tissue repair and regeneration. After introducing tissue repair and regeneration, the review focuses on biodegradable and biocompatible biomaterials such as collagen, polysaccharides, silk proteins, polyesters and their derivatives, characterized by the most promising outputs in biomedical science. Attention is pointed out also to those biomaterials exerting peculiar activities, e.g., antibacterial. The regulatory frame applied to pre-clinical and early clinical studies is also outlined by distinguishing between Advanced Therapy Medicinal Products and Medical Devices.
Collapse
Affiliation(s)
| | | | | | - Bice Conti
- Correspondence: (M.C.B.); (B.C.); (F.F.)
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Sun M, Huang S, Yu M, Han K. Toughening Modification of Polylactic Acid by Thermoplastic Silicone Polyurethane Elastomer. Polymers (Basel) 2021; 13:1953. [PMID: 34208303 PMCID: PMC8231260 DOI: 10.3390/polym13121953] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/09/2021] [Accepted: 06/09/2021] [Indexed: 12/21/2022] Open
Abstract
The melt blending of polylactic acid (PLA) and thermoplastic silicone polyurethane (TPSiU) elastomer was performed to toughen PLA. The molecular structure, crystallization, thermal properties, compatibility, mechanical properties and rheological properties of the PLA/TPSiU blends of different mass ratios (100/0, 95/5, 90/10, 85/15 and 80/20) were investigated. The results showed that TPSiU was effectively blended into PLA, but no chemical reaction occurred. The addition of TPSiU had no obvious effect on the glass transition temperature and melting temperature of PLA, but slightly reduced the crystallinity of PLA. The morphology and dynamic mechanical analysis results demonstrated the poor thermodynamic compatibility between PLA and TPSiU. Rheological behavior studies showed that PLA/TPSiU melt was typically pseudoplastic fluid. As the content of TPSiU increased, the apparent viscosity of PLA/TPSiU blends showed a trend of rising first and then falling. The addition of TPSiU had a significant effect on the mechanical properties of PLA/TPSiU blends. When the content of TPSiU was 15 wt%, the elongation at break of the PLA/TPSiU blend reached 22.3% (5.0 times that of pure PLA), and the impact strength reached 19.3 kJ/m2 (4.9 times that of pure PLA), suggesting the favorable toughening effect.
Collapse
Affiliation(s)
| | | | | | - Keqing Han
- College of Materials Science and Engineering, Donghua University, Shanghai 201620, China; (M.S.); (S.H.); (M.Y.)
| |
Collapse
|
5
|
Jia S, Chen Y, Bian J, Pan H, Wang X, Zhao L, Han L, Zhang H, Dong L, Zhang H. Preparation and properties of poly(L-lactic acid) blends with excellent low-temperature toughness by blending acrylic ester based impact resistance agent. Int J Biol Macromol 2021; 183:1871-1880. [PMID: 34087292 DOI: 10.1016/j.ijbiomac.2021.05.177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/10/2021] [Accepted: 05/26/2021] [Indexed: 10/21/2022]
Abstract
Poly(L-lactic acid) (PLLA) blends with excellent low-temperature toughness and strength were prepared by melt compounding with acrylic ester based impact resistance agent (AEIR). The morphology, thermal properties, mechanical properties and biodegradability of the blends were investigated. Morphology observations revealed the blend was immiscible but had good compatibility with the dispersed phase size of about 200-300 nm. With the addition of AEIR, dramatic improvement in toughness of PLLA was achieved in a wide temperature range, especially at low temperatures the tensile strength was effectively remained. For the blend with 20 wt% AEIR, the tensile strength, elongation at break and impact strength were 51.6 MPa, 72% and 77.1 KJ/m2 at -20 °C, respectively, much greater than that reported. The calculated Tg of AEIR was lower than the test temperatures, and the brittle-tough transition occurred. The PLLA matrix demonstrated obvious shear yielding which induced energy dissipation and therefore lead to excellent toughness of the blends. Moreover, the biodegradation of PLLA was enhanced after blends preparation.
Collapse
Affiliation(s)
- Shiling Jia
- School of Materials Science and Engineering, Changchun University of Technology, Changchun 130012, China; Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Yunjing Chen
- Sinopec-SK (Wuhan) Petrochemical Company Limited, Wuhan 430000, China
| | - Junjia Bian
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Hongwei Pan
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Xiangyu Wang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Ling Zhao
- School of Materials Science and Engineering, Changchun University of Technology, Changchun 130012, China
| | - Lijing Han
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
| | - Huiliang Zhang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
| | - Lisong Dong
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Huixuan Zhang
- School of Materials Science and Engineering, Changchun University of Technology, Changchun 130012, China
| |
Collapse
|
6
|
Fenni SE, Bertella F, Monticelli O, Müller AJ, Hadadoui N, Cavallo D. Renewable and Tough Poly(l-lactic acid)/Polyurethane Blends Prepared by Dynamic Vulcanization. ACS OMEGA 2020; 5:26421-26430. [PMID: 33110970 PMCID: PMC7581077 DOI: 10.1021/acsomega.0c02765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
Melt blending of homopolymers is an effective way to achieve an attractive combination of polymer properties. Dynamic vulcanization of fatty-acid-based polyester polyol with glycerol and poly(l-lactic acid) (PLLA) in the presence of hexamethylene diisocyanate (HDI) was performed with the aim of toughening PLLA. The dynamic vulcanization in an internal mixer led to the formation of a PLLA/PU biobased blend. Melt torque, Fourier transform infrared (FTIR), and gel fraction analysis demonstrated the successful formation of cross-linked polyurethane (PU) inside the PLLA matrix. Scanning electron microscopy (SEM) analysis showed that the PLLA/PU blends exhibit a sea-island morphology. Gel fraction analysis revealed that a rubbery phase was formed inside the PLLA matrix, which was insoluble in chloroform. FTIR analysis of the insoluble part shows the appearance of an absorption band centered at 1758 cm-1, related to the crystalline carbonyl vibration of the PLLA component, thus suggesting the partial involvement of PLLA chains in the cross-linking reaction. The overall content of the PU phase in the blends significantly affected the mechanical properties, thermal stability, and crystallization behavior of the materials. The overall crystallization rate of PLLA was noticeably decreased by the incorporation of PU. At the same time, polarized light optical microscopy (PLOM) analysis revealed that the presence of the PU rubbery phase inside the PLLA matrix promoted PLLA nucleation. With the formation of the PU network, the impact strength showed a remarkable increase while Young's modulus correspondingly decreased. The blends showed slightly reduced thermal stability compared to the neat PLLA.
Collapse
Affiliation(s)
- Seif Eddine Fenni
- Department
of Chemistry and Industrial Chemistry, University
of Genova, via Dodecaneso, 31, 16146 Genova, Italy
- Laboratory
of Physical-Chemistry of High Polymers (LPCHP), Faculty of Technology, University of Ferhat ABBAS Sétif-1, 19000 Sétif, Algeria
| | - Francesca Bertella
- Department
of Chemistry and Industrial Chemistry, University
of Genova, via Dodecaneso, 31, 16146 Genova, Italy
| | - Orietta Monticelli
- Department
of Chemistry and Industrial Chemistry, University
of Genova, via Dodecaneso, 31, 16146 Genova, Italy
| | - Alejandro J. Müller
- POLYMAT
and Polymer Science and Technology Department, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizábal,
3, 20018 Donostia-San
Sebastiá, Spain
- IKERBASQUE,
Basque Foundation for Science, 48013 Bilbao, Spain
| | - Nacerddine Hadadoui
- Laboratory
of Physical-Chemistry of High Polymers (LPCHP), Faculty of Technology, University of Ferhat ABBAS Sétif-1, 19000 Sétif, Algeria
| | - Dario Cavallo
- Department
of Chemistry and Industrial Chemistry, University
of Genova, via Dodecaneso, 31, 16146 Genova, Italy
| |
Collapse
|
7
|
Wang Z, Zhang C, Zhang Z, Chen X, Wang X, Wen M, Chen B, Cao W, Liu C. Polyethylene oxide enhances the ductility and toughness of polylactic acid: the role of mesophase. SOFT MATTER 2020; 16:7018-7032. [PMID: 32648874 DOI: 10.1039/d0sm00671h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A lack of understanding of the structure-property relationship of the polylactic acid (PLA)-based polymer composite system makes it a challenge to manufacture products with optimized mechanical performance by precisely regulating the microscopic structure and morphology. Herein, we chose the PLA/polyethylene oxide (PEO) blend as a model to investigate the structural reason for the enhanced ductility and toughness of this kind of material. We have demonstrated that a considerable amount of the PLA mesophases exist in the melt quenched films that display high ductility and toughness, in contrast to the PLA crystals in their counterparts of slowly cooled films that are dominated by brittle fracture. The mesophase formed by melt quenching is attributed to a moderate acceleration of PLA chain mobility due to the plasticizing effect of the flexible PEO. In situ experiments have revealed the further formation of oriented mesophases induced by tensile deformation, which presents a high consistency between the content increase and the tensile stress intensification. We illustrate that the mesophases directly develop into a microfibrillar morphology to transmit the external stress and prevent crack propagation under deformation. This work emphasizes the essential role of the PLA mesophase in acquiring the enhanced ductility and toughness of the PLA/PEO composite films, which may be generalized to other similar PLA-based polymer composite materials.
Collapse
Affiliation(s)
- Zhen Wang
- National Engineering Research Center for Advanced Polymer Processing Technology, Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, Zhengzhou University, Zhengzhou, 450002, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Li Z, Shi S, Yang F, Cao D, Zhang K, Wang B, Ma Z, Pan L, Li Y. Supertough and Transparent Poly(lactic acid) Nanostructure Blends with Minimal Stiffness Loss. ACS OMEGA 2020; 5:13148-13157. [PMID: 32548501 PMCID: PMC7288571 DOI: 10.1021/acsomega.0c01165] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 05/12/2020] [Indexed: 05/04/2023]
Abstract
This contribution is an attempt to explore the effectiveness of a series of newly obtained thermoplastic elastomers (TPEs) as a toughening agent for modifying poly(lactic acid) (PLA). The TPEs, including ionically modified isotactic polypropylene-graft-PLA (iPP-g-PLA) copolymers with explicit graft length, graft density, and ionic group content, and an iPP-g-PLA copolymer with a very high molecular weight and explicit graft density, were elaborately designed and synthesized. The semicrystal or rubbery copolymer backbone originated from iPP was designed to improve the toughness and maintain a relatively high strength, while the grafted PLA side chain was to ensure a high level of compatibility with the PLA matrix. To obtain further enhancement in interfacial reinforcement, the imidazolium-based ionic group was also added during graft onto reaction. All of these graft copolymers were identified with randomly distributed PLA branches, bearing a very high molecular weight ((33-398) × 104) and very high PLA content (57.3-89.3 wt %). Unprecedentedly, with a very small amount of newly designed TPE, the modified PLA blends exhibited a significantly increased elongation at break (up to about 190%) and simultaneously retained the very high stiffness and excellent transparency. The nanometer-scale phase-separated particles with good compatibility and refractive index matching to the PLA matrix were demonstrated to play a crucial role in the excellent performance. The findings suggested that the newly designed iPP-g-PLA copolymers are very economic, promising, and effective modifying agents for developing highly transparent and tough PLA-based sustainable materials.
Collapse
Affiliation(s)
- Zhaoxin Li
- Tianjin
Key Lab of Composite & Functional Materials, School of Materials
Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Shuwen Shi
- Tianjin
Key Lab of Composite & Functional Materials, School of Materials
Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Fei Yang
- Tianjin
Key Lab of Composite & Functional Materials, School of Materials
Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Dafu Cao
- Tianjin
Key Lab of Composite & Functional Materials, School of Materials
Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Kunyu Zhang
- School
of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
| | - Bin Wang
- Tianjin
Key Lab of Composite & Functional Materials, School of Materials
Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Zhe Ma
- Tianjin
Key Lab of Composite & Functional Materials, School of Materials
Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Li Pan
- Tianjin
Key Lab of Composite & Functional Materials, School of Materials
Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yuesheng Li
- Tianjin
Key Lab of Composite & Functional Materials, School of Materials
Science and Engineering, Tianjin University, Tianjin 300072, China
- Collaborative
Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| |
Collapse
|
9
|
Study on miscibility, thermal properties, degradation behaviors, and toughening mechanism of poly(lactic acid)/poly (ethylene-butylacrylate-glycidyl methacrylate) blends. Int J Biol Macromol 2020; 143:443-452. [DOI: 10.1016/j.ijbiomac.2019.11.226] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 11/08/2019] [Accepted: 11/28/2019] [Indexed: 11/19/2022]
|
10
|
Zhao X, Hu H, Wang X, Yu X, Zhou W, Peng S. Super tough poly(lactic acid) blends: a comprehensive review. RSC Adv 2020; 10:13316-13368. [PMID: 35492128 PMCID: PMC9051451 DOI: 10.1039/d0ra01801e] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 03/21/2020] [Indexed: 12/18/2022] Open
Abstract
Poly(lactic acid) or poly(lactide) (PLA) is a renewable, bio-based, and biodegradable aliphatic thermoplastic polyester that is considered a promising alternative to petrochemical-derived polymers in a wide range of commodity and engineering applications. However, PLA is inherently brittle, with less than 10% elongation at break and a relatively poor impact strength, which limit its use in some specific areas. Therefore, enhancing the toughness of PLA has been widely explored in academic and industrial fields over the last two decades. This work aims to summarize and organize the current development in super tough PLA fabricated via polymer blending. The miscibility and compatibility of PLA-based blends, and the methods and approaches for compatibilized PLA blends are briefly discussed. Recent advances in PLA modified with various polymers for improving the toughness of PLA are also summarized and elucidated systematically in this review. Various polymers used in toughening PLA are discussed and organized: elastomers, such as petroleum-based traditional polyurethanes (PUs), bio-based elastomers, and biodegradable polyester elastomers; glycidyl ester compatibilizers and their copolymers/elastomers, such as poly(ethylene-co-glycidyl methacrylate) (EGMA), poly(ethylene-n-butylene-acrylate-co-glycidyl methacrylate) (EBA-GMA); rubber; petroleum-based traditional plastics, such as PE and PP; and various biodegradable polymers, such as poly(butylene adipate-co-terephthalate) (PBAT), polycaprolactone (PCL), poly(butylene succinate) (PBS), and natural macromolecules, especially starch. The high tensile toughness and high impact strength of PLA-based blends are briefly outlined, while the super tough PLA-based blends with impact strength exceeding 50 kJ m−2 are elucidated in detail. The toughening strategies and approaches of PLA based super tough blends are summarized and analyzed. The relationship of the properties of PLA-based blends and their morphological parameters, including particle size, interparticle distance, and phase morphologies, are presented. PLA is a renewable, bio-based, and biodegradable aliphatic thermoplastic polyester that is considered a promising alternative to petrochemical-derived polymers in a wide range of commodity and engineering applications.![]()
Collapse
Affiliation(s)
- Xipo Zhao
- Hubei Provincial Key Laboratory of Green Materials for Light Industry
- Collaborative Innovation Center of Green Light-weight Materials and Processing
- Hubei University of Technology
- Wuhan 430068
- China
| | - Huan Hu
- Hubei Provincial Key Laboratory of Green Materials for Light Industry
- Collaborative Innovation Center of Green Light-weight Materials and Processing
- Hubei University of Technology
- Wuhan 430068
- China
| | - Xin Wang
- Hubei Provincial Key Laboratory of Green Materials for Light Industry
- Collaborative Innovation Center of Green Light-weight Materials and Processing
- Hubei University of Technology
- Wuhan 430068
- China
| | - Xiaolei Yu
- Hubei Provincial Key Laboratory of Green Materials for Light Industry
- Collaborative Innovation Center of Green Light-weight Materials and Processing
- Hubei University of Technology
- Wuhan 430068
- China
| | - Weiyi Zhou
- Hubei Provincial Key Laboratory of Green Materials for Light Industry
- Collaborative Innovation Center of Green Light-weight Materials and Processing
- Hubei University of Technology
- Wuhan 430068
- China
| | - Shaoxian Peng
- Hubei Provincial Key Laboratory of Green Materials for Light Industry
- Collaborative Innovation Center of Green Light-weight Materials and Processing
- Hubei University of Technology
- Wuhan 430068
- China
| |
Collapse
|
11
|
Samthong C, Kunanusont N, Deetuam C, Wongkhan T, Supannasud T, Somwangthanaroj A. Effect of acrylonitrile content of acrylonitrile butadiene rubber on mechanical and thermal properties of dynamically vulcanized poly(lactic acid) blends. POLYM INT 2019. [DOI: 10.1002/pi.5912] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Chavakorn Samthong
- Department of Chemical Engineering, Faculty of EngineeringChulalongkorn University Bangkok Thailand
| | - Nappaphan Kunanusont
- Department of Chemical Engineering, Faculty of EngineeringChulalongkorn University Bangkok Thailand
| | - Chutimar Deetuam
- Department of Chemical Engineering, Faculty of EngineeringChulalongkorn University Bangkok Thailand
| | - Tanchanok Wongkhan
- Department of Chemical Engineering, Faculty of EngineeringChulalongkorn University Bangkok Thailand
| | - Thanapat Supannasud
- Department of Chemical Engineering, Faculty of EngineeringChulalongkorn University Bangkok Thailand
| | - Anongnat Somwangthanaroj
- Department of Chemical Engineering, Faculty of EngineeringChulalongkorn University Bangkok Thailand
- Special Task Force of Activating Research (STAR) in Novel Technology for Food Packaging and Control of Shelf LifeChulalongkorn University Bangkok Thailand
| |
Collapse
|
12
|
Mechanical, rheological and anaerobic biodegradation behavior of a Poly(lactic acid) blend containing a Poly(lactic acid)-co-poly(glycolic acid) copolymer. Polym Degrad Stab 2019. [DOI: 10.1016/j.polymdegradstab.2019.109018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
13
|
Haugan IN, Lee B, Maher MJ, Zografos A, Schibur HJ, Jones SD, Hillmyer MA, Bates FS. Physical Aging of Polylactide-Based Graft Block Polymers. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01434] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
| | | | | | | | | | - Seamus D. Jones
- Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | | | | |
Collapse
|
14
|
Zuo X, Xue Y, Wang L, Zhou Y, Yin Y, Chuang YC, Chang CC, Yin R, Rafailovich MH, Guo Y. Engineering Styrenic Blends with Poly(lactic acid). Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01349] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xianghao Zuo
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
| | - Yuan Xue
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
- ThINC Facility, Advanced Energy Center, Stony Brook, New York 11794, United States
| | - Likun Wang
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
| | - Yuchen Zhou
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
| | - Yifan Yin
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
| | - Ya-Chen Chuang
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
- ThINC Facility, Advanced Energy Center, Stony Brook, New York 11794, United States
| | - Chung-Chueh Chang
- ThINC Facility, Advanced Energy Center, Stony Brook, New York 11794, United States
| | - Ruilin Yin
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
| | - Miriam H. Rafailovich
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
| | - Yichen Guo
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
| |
Collapse
|
15
|
Jia S, Chen Y, Yu Y, Han L, Zhang H, Dong L. Effect of Ethylene/butyl methacrylate/Glycidyl Methacrylate Terpolymer on toughness and biodegradation of poly (l-lactic acid). Int J Biol Macromol 2019; 127:415-424. [DOI: 10.1016/j.ijbiomac.2019.01.068] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/09/2019] [Accepted: 01/15/2019] [Indexed: 10/27/2022]
|
16
|
Poly (lactic acid) blends: Processing, properties and applications. Int J Biol Macromol 2018; 125:307-360. [PMID: 30528997 DOI: 10.1016/j.ijbiomac.2018.12.002] [Citation(s) in RCA: 282] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/29/2018] [Accepted: 12/01/2018] [Indexed: 11/21/2022]
Abstract
Poly (lactic acid) or polylactide (PLA) is a commercial biobased, biodegradable, biocompatible, compostable and non-toxic polymer that has competitive material and processing costs and desirable mechanical properties. Thereby, it can be considered favorably for biomedical applications and as the most promising substitute for petroleum-based polymers in a wide range of commodity and engineering applications. However, PLA has some significant shortcomings such as low melt strength, slow crystallization rate, poor processability, high brittleness, low toughness, and low service temperature, which limit its applications. To overcome these limitations, blending PLA with other polymers is an inexpensive approach that could also tailor the final properties of PLA-based products. During the last two decades, researchers investigated the synthesis, processing, properties, and development of various PLA-based blend systems including miscible blends of poly l-lactide (PLLA) and poly d-lactide (PDLA), which generate stereocomplex crystals, binary immiscible/miscible blends of PLA with other thermoplastics, multifunctional ternary blends using a third polymer or fillers such as nanoparticles, as well as PLA-based blend foam systems. This article reviews all these investigations and compares the syntheses/processing-morphology-properties interrelationships in PLA-based blends developed so far for various applications.
Collapse
|
17
|
Nematollahi M, Jalali-Arani A, Modarress H. High-performance bio-based poly(lactic acid)/natural rubber/epoxidized natural rubber blends: effect of epoxidized natural rubber on microstructure, toughness and static and dynamic mechanical properties. POLYM INT 2018. [DOI: 10.1002/pi.5727] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Mahsa Nematollahi
- Department of Polymer Engineering and Color Technology; Amirkabir University of Technology; Tehran Iran
| | - Azam Jalali-Arani
- Department of Polymer Engineering and Color Technology; Amirkabir University of Technology; Tehran Iran
| | - Hamid Modarress
- Department of Chemical Engineering; Amirkabir University of Technology; Tehran Iran
| |
Collapse
|
18
|
Konwar DB, Satapathy BK, Jacob J. Influence of aliphatic polycarbonate middle block on mechanical and microstructural behaviour of triblock copolymers based on poly(l
-lactide) and polycarbonate. POLYM INT 2018. [DOI: 10.1002/pi.5723] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Debanga B Konwar
- Department of Materials Science and Engineering; Indian Institute of Technology Delhi; New Delhi India
| | - Bhabani K Satapathy
- Department of Materials Science and Engineering; Indian Institute of Technology Delhi; New Delhi India
| | - Josemon Jacob
- Department of Materials Science and Engineering; Indian Institute of Technology Delhi; New Delhi India
| |
Collapse
|
19
|
Yang DD, Liu W, Zhu HM, Wu G, Chen SC, Wang XL, Wang YZ. Toward Super-Tough Poly(l-lactide) via Constructing Pseudo-Cross-link Network in Toughening Phase Anchored by Stereocomplex Crystallites at the Interface. ACS APPLIED MATERIALS & INTERFACES 2018; 10:26594-26603. [PMID: 30019579 DOI: 10.1021/acsami.8b06343] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrated a novel strategy to toughen poly(l-lactide) (PLLA) by constructing pseudo-cross-link networks based on chain entanglements of long-chain branched structure in the toughening phase, which were anchored by stereocomplex (SC) crystallites at the interface. The formation of pseudo-cross-link network was achieved by simple blending of the copolymer of long-chain branched polycaprolactone and poly(d-lactide) (LB-PCL- b-DLA) with PLLA without introducing any chemical cross-linking structure or nonbiodegradable component. The microscopic morphology analysis suggests that the interface-formed SC crystallites not only enhanced the interfacial interaction between LB-PCL and PLLA but also obviously increased the matrix crystallization rate. Different from those blends without SC crystallites or long-chain branched structures, nano-microgels were observed in chloroform solution of the PLLA/LB-PCL- b-DLA blend, suggesting the formation of pseudo-cross-link network. The pseudo-cross-link network in LB-PCL toughening phase endows PLLA a significantly improved impact toughness (49.5 kJ/m2), which is almost 13 times than that of neat PLLA. Moreover, matrix crystallinity and spherulite size of the PLLA matrix also play significant roles in toughening. Only sufficiently crystallized PLLA with proper spherulite size can effectively trigger the matrix shear yielding, meanwhile, facilitate the energy dissipating.
Collapse
Affiliation(s)
- Dan-Dan Yang
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, College of Chemistry , Sichuan University , Chengdu 610064 , China
| | - Wen Liu
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, College of Chemistry , Sichuan University , Chengdu 610064 , China
| | - Hong-Mei Zhu
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, College of Chemistry , Sichuan University , Chengdu 610064 , China
| | - Gang Wu
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, College of Chemistry , Sichuan University , Chengdu 610064 , China
| | - Si-Chong Chen
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, College of Chemistry , Sichuan University , Chengdu 610064 , China
| | - Xiu-Li Wang
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, College of Chemistry , Sichuan University , Chengdu 610064 , China
| | - Yu-Zhong Wang
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, College of Chemistry , Sichuan University , Chengdu 610064 , China
| |
Collapse
|
20
|
Wang B, Ren R, Chen Z. Synthesis of cross-linked polylactide–poly(tetramethylene oxide) copolymers with enhanced toughness. Polym Bull (Berl) 2018. [DOI: 10.1007/s00289-018-2452-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
21
|
|
22
|
Konwar DB, Sethy S, Satapathy BK, Jacob J. Effect of poly(l-lactide) chain length on microstructural and thermo-mechanical properties of poly(l-lactide)-b-poly(butylene carbonate)-b-poly(l-lactide) triblock copolymers. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.07.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
23
|
Ru JF, Yang SG, Lei J, Li ZM. Thicker Lamellae and Higher Crystallinity of Poly(lactic acid) via Applying Shear Flow and Pressure and Adding Poly(ethylene Glycol). J Phys Chem B 2017; 121:5842-5852. [DOI: 10.1021/acs.jpcb.7b02241] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jia-Feng Ru
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Shu-Gui Yang
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Jun Lei
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Zhong-Ming Li
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| |
Collapse
|
24
|
Leroux F, Montembault V, Piogé S, Pascual S, Fontaine L. Poly(1,4-butadiene)-graft-poly(L-lactide) via the grafting-from strategy. Polym Bull (Berl) 2017. [DOI: 10.1007/s00289-017-1961-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
25
|
Huang T, Yamaguchi M. Effect of cooling conditions on the mechanical properties of crystalline poly(lactic acid). J Appl Polym Sci 2017. [DOI: 10.1002/app.44960] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Tong Huang
- School of Materials Science; Japan Advanced Institute of Science and Technology; 1-1 Asahidai Nomi Ishikawa 923-1292 Japan
| | - Masayuki Yamaguchi
- School of Materials Science; Japan Advanced Institute of Science and Technology; 1-1 Asahidai Nomi Ishikawa 923-1292 Japan
| |
Collapse
|
26
|
Greatly enhanced hydrolytic degradation ability of poly(L-lactide) achieved by adding poly(ethylene glycol). CHINESE JOURNAL OF POLYMER SCIENCE 2017. [DOI: 10.1007/s10118-017-1904-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
27
|
Peng N, Lv R, Jin T, Na B, Liu H, Zhou H. Thermal and strain-induced phase separation in an ionic liquid plasticized polylactide. POLYMER 2017. [DOI: 10.1016/j.polymer.2016.12.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
28
|
Wang Y, Xia M, Kong X, Severtson SJ, Wang WJ. Tailoring chain structures of l-lactide and ε-caprolactone copolyester macromonomers using rac-binaphthyl-diyl hydrogen phosphate-catalyzed ring-opening copolymerization with monomer addition strategy. RSC Adv 2017. [DOI: 10.1039/c7ra05531e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
rac-BNPH catalyzed ring-opening copolymerization of l-lactide and ε-caprolactone with monomer addition strategy effectively tailoring chain structures of macromonomers.
Collapse
Affiliation(s)
- Yanjiao Wang
- State Key Laboratory of Chemical Engineering
- College of Chemical and Biological Engineering
- Zhejiang University
- Hangzhou
- China 310027
| | - Ming Xia
- Department of Chemistry
- Zhejiang University
- Hangzhou 310027
- China 310027
| | - Xueqiang Kong
- Department of Chemistry
- Zhejiang University
- Hangzhou 310027
- China 310027
| | - Steven John Severtson
- Department of Bioproducts and Biosystems Engineering
- University of Minnesota
- Saint Paul
- USA 55108
| | - Wen-Jun Wang
- State Key Laboratory of Chemical Engineering
- College of Chemical and Biological Engineering
- Zhejiang University
- Hangzhou
- China 310027
| |
Collapse
|
29
|
Jing J, Zhang Y, Tang X, Zhou Y, Li X, Kandola BK, Fang Z. Layer by layer deposition of polyethylenimine and bio-based polyphosphate on ammonium polyphosphate: A novel hybrid for simultaneously improving the flame retardancy and toughness of polylactic acid. POLYMER 2017. [DOI: 10.1016/j.polymer.2016.12.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
30
|
Chile LE, Ebrahimi T, Wong A, Aluthge DC, Hatzikiriakos SG, Mehrkhodavandi P. Impact of aryloxy initiators on the living and immortal polymerization of lactide. Dalton Trans 2017; 46:6723-6733. [DOI: 10.1039/c7dt00990a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This report describes two different methodologies for the synthesis of aryl end-functionalized poly(lactide)s (PLAs) catalyzed by indium complexes.
Collapse
Affiliation(s)
- L.-E. Chile
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
- Department of Chemical and Biological Engineering
| | - T. Ebrahimi
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
- Department of Chemical and Biological Engineering
| | - A. Wong
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | - D. C. Aluthge
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | - S. G. Hatzikiriakos
- Department of Chemical and Biological Engineering
- University of British Columbia
- Vancouver
- Canada
| | - P. Mehrkhodavandi
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| |
Collapse
|
31
|
Vanbiervliet E, Fouquay S, Michaud G, Simon F, Carpentier JF, Guillaume SM. From Epoxide to Cyclodithiocarbonate Telechelic Polycyclooctene through Chain-Transfer Ring-Opening Metathesis Polymerization (ROMP): Precursors to Non-Isocyanate Polyurethanes (NIPUs). Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b02137] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Elise Vanbiervliet
- Institut
des Sciences Chimiques de Rennes (ISCR), UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 263 Avenue du
Général Leclerc, F-35042 Rennes, Cedex, France
| | - Stéphane Fouquay
- BOSTIK S.A., 253, Avenue du Président Wilson, F-93211 La Plaine Saint-Denis, France
| | - Guillaume Michaud
- BOSTIK, ZAC du Bois
de Plaisance, 101, Rue du Champ Cailloux, F-60280 Venette, France
| | - Frédéric Simon
- BOSTIK, ZAC du Bois
de Plaisance, 101, Rue du Champ Cailloux, F-60280 Venette, France
| | - Jean-François Carpentier
- Institut
des Sciences Chimiques de Rennes (ISCR), UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 263 Avenue du
Général Leclerc, F-35042 Rennes, Cedex, France
| | - Sophie M. Guillaume
- Institut
des Sciences Chimiques de Rennes (ISCR), UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 263 Avenue du
Général Leclerc, F-35042 Rennes, Cedex, France
| |
Collapse
|
32
|
|
33
|
Ru JF, Yang SG, Zhou D, Yin HM, Lei J, Li ZM. Dominant β-Form of Poly(l-lactic acid) Obtained Directly from Melt under Shear and Pressure Fields. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00595] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Jia-Feng Ru
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Shu-Gui Yang
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Dong Zhou
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Hua-Mo Yin
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Jun Lei
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Zhong-Ming Li
- College of Polymer Science
and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| |
Collapse
|
34
|
Li T, Zhang J, Schneiderman DK, Francis LF, Bates FS. Toughening Glassy Poly(lactide) with Block Copolymer Micelles. ACS Macro Lett 2016; 5:359-364. [PMID: 35614704 DOI: 10.1021/acsmacrolett.6b00063] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Poly(lactide) (PLA), a compostable bioderived polyester, can be produced at a cost and scale that makes it an attractive replacement for nondegradable petroleum-derived thermoplastics. However, pristine PLA is brittle and unsuitable for use in applications where high impact strength and ductility are required. In this work we demonstrate that poly(l-lactide) (PLLA) in the glassy state can be toughened significantly via addition of an amphiphilic diblock polymer. Notably, a PLLA blend containing only 5 wt% poly(ethylene oxide)-b-poly(butylene oxide) (PEO-PBO) exhibited tensile toughness and notched Izod impact strength over an order of magnitude higher than neat amorphous PLLA without a significant reduction in transparency or elastic modulus. For a series of PLLA blends containing PEO-PBO of fixed composition (∼70% volume fraction PBO), the toughness was inversely related to the molar mass of the added modifier with the highest toughness observed for the blend containing the smallest diblock (∼7 kg/mol). Interestingly, at fixed composition and molar mass poly(l-lactide)-b-poly(butylene oxide) (PLLA-PBO) exhibited a substantial but reduced toughening efficiency compared to PEO-PBO. We attribute this difference to a change in the solubility parameter of the amphiphilc block. Using TEM, we show that the greatest toughening is observed when the diblock modifier forms small cylindrical micelles that are well dispersed in the PLLA matrix. This morphology is facilitated by a negative Flory-Huggins interaction parameter (χ) between PEO and PLLA. These insights suggest a new and versatile strategy for the facile and efficient toughening of brittle thermoplastics.
Collapse
Affiliation(s)
- Tuoqi Li
- Department of Chemical Engineering
and Materials Sciences and ‡Department of
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Jiuyang Zhang
- Department of Chemical Engineering
and Materials Sciences and ‡Department of
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Deborah K. Schneiderman
- Department of Chemical Engineering
and Materials Sciences and ‡Department of
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Lorraine F. Francis
- Department of Chemical Engineering
and Materials Sciences and ‡Department of
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Frank S. Bates
- Department of Chemical Engineering
and Materials Sciences and ‡Department of
Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
35
|
Rheology, mechanical properties and crystallization behavior of glycidyl methacrylate grafted poly(ethylene octene) toughened poly(lactic acid) blends. KOREAN J CHEM ENG 2016. [DOI: 10.1007/s11814-015-0202-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
36
|
Yang J, Nie S, Zhu J. A comparative study on different rubbery modifiers: Effect on morphologies, mechanical, and thermal properties of PLA blends. J Appl Polym Sci 2016. [DOI: 10.1002/app.43340] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Jinian Yang
- School of Materials Science and Engineering; Anhui University of Science and Technology; Huainan 232001 People's Republic of China
| | - Shibin Nie
- School of Mining and Safety Engineering; Anhui University of Science and Technology; Huainan 232001 People's Republic of China
| | - Jinbo Zhu
- School of Materials Science and Engineering; Anhui University of Science and Technology; Huainan 232001 People's Republic of China
| |
Collapse
|
37
|
Leng X, Wei Z, Bian Y, Ren Y, Wang Y, Wang Q, Li Y. Rheological properties and crystallization behavior of comb-like graft poly(l-lactide): influences of graft length and graft density. RSC Adv 2016. [DOI: 10.1039/c6ra02697d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Radius growth rate of spherulites (G) versus crystallization temperature (Tc) for graft PLLA with different graft density and graft length.
Collapse
Affiliation(s)
- Xuefei Leng
- State Key Laboratory of Fine Chemicals
- Department of Polymer Materials
- School of Chemical Engineering
- Dalian University of Technology
- Dalian 116024
| | - Zhiyong Wei
- State Key Laboratory of Fine Chemicals
- Department of Polymer Materials
- School of Chemical Engineering
- Dalian University of Technology
- Dalian 116024
| | - Yufei Bian
- State Key Laboratory of Fine Chemicals
- Department of Polymer Materials
- School of Chemical Engineering
- Dalian University of Technology
- Dalian 116024
| | - Yingying Ren
- State Key Laboratory of Fine Chemicals
- Department of Polymer Materials
- School of Chemical Engineering
- Dalian University of Technology
- Dalian 116024
| | - Yurong Wang
- State Key Laboratory of Fine Chemicals
- Department of Polymer Materials
- School of Chemical Engineering
- Dalian University of Technology
- Dalian 116024
| | - Qinyi Wang
- State Key Laboratory of Fine Chemicals
- Department of Polymer Materials
- School of Chemical Engineering
- Dalian University of Technology
- Dalian 116024
| | - Yang Li
- State Key Laboratory of Fine Chemicals
- Department of Polymer Materials
- School of Chemical Engineering
- Dalian University of Technology
- Dalian 116024
| |
Collapse
|
38
|
Deokar MD, Idage SB, Idage BB, Sivaram S. Synthesis and characterization of well-defined random and block copolymers of ε-caprolactone withl-lactide as an additive for toughening polylactide: Influence of the molecular architecture. J Appl Polym Sci 2015. [DOI: 10.1002/app.43267] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Megha D. Deokar
- Polymer Science and Engineering Division; Council of Scientific and Industrial Research-National Chemical Laboratory; Pune 411 008 India
| | - Susheela B. Idage
- Polymer Science and Engineering Division; Council of Scientific and Industrial Research-National Chemical Laboratory; Pune 411 008 India
| | - Bhaskar B. Idage
- Polymer Science and Engineering Division; Council of Scientific and Industrial Research-National Chemical Laboratory; Pune 411 008 India
| | - Swaminathan Sivaram
- Polymer Science and Engineering Division; Council of Scientific and Industrial Research-National Chemical Laboratory; Pune 411 008 India
| |
Collapse
|
39
|
Qi F, Tang M, Chen X, Chen M, Guo G, Zhang Z. Morphological structure, thermal and mechanical properties of tough poly(lactic acid) upon stereocomplexes. Eur Polym J 2015. [DOI: 10.1016/j.eurpolymj.2015.08.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
40
|
Tanjung FA, Hassan A, Hasan M. Use of epoxidized natural rubber as a toughening agent in plastics. J Appl Polym Sci 2015. [DOI: 10.1002/app.42270] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Faisal Amri Tanjung
- Enhanced Polymer Research Group; Department of Polymer Engineering; Faculty of Chemical Engineering, Universiti Teknologi Malaysia; 81310 Skudai Johor Malaysia
| | - Azman Hassan
- Enhanced Polymer Research Group; Department of Polymer Engineering; Faculty of Chemical Engineering, Universiti Teknologi Malaysia; 81310 Skudai Johor Malaysia
| | - Mahbub Hasan
- Department of Materials and Metallurgical Engineering; Bangladesh University of Engineering and Technology; Dhaka 1000 Bangladesh
| |
Collapse
|
41
|
Yin Q, Yin L, Wang H, Cheng J. Synthesis and biomedical applications of functional poly(α-hydroxy acids) via ring-opening polymerization of O-carboxyanhydrides. Acc Chem Res 2015; 48:1777-87. [PMID: 26065588 DOI: 10.1021/ar500455z] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Poly(α-hydroxy acids) (PAHAs) are a class of biodegradable and biocompatible polymers that are widely used in numerous applications. One drawback of these conventional polymers, however, is their lack of side-chain functionalities, which makes it difficult to conjugate active moieties to PAHA or to fine-tune the physical and chemical properties of PAHA-derived materials through side-chain modifications. Thus, extensive efforts have been devoted to the development of methodology that allows facile preparation of PAHAs with controlled molecular weights and a variety of functionalities for widespread utilities. However, it is highly challenging to introduce functional groups into conventional PAHAs derived from ring-opening polymerization (ROP) of lactides and glycolides to yield functional PAHAs with favorable properties, such as tunable hydrophilicity/hydrophobicity, facile postpolymerization modification, and well-defined physicochemical properties. Amino acids are excellent resources for functional polymers because of their low cost, availability, and structural as well as stereochemical diversity. Nevertheless, the synthesis of functional PAHAs using amino acids as building blocks has been rarely reported because of the difficulty of preparing large-scale monomers and poor yields during the synthesis. The synthesis of functionalized PAHAs from O-carboxyanhydrides (OCAs), a class of five-membered cyclic anhydrides derived from amino acids, has proven to be one of the most promising strategies and has thus attracted tremendous interest recently. In this Account, we highlight the recent progress in our group on the synthesis of functional PAHAs via ROP of OCAs and their self-assembly and biomedical applications. New synthetic methodologies that allow the facile preparation of PAHAs with controlled molecular weights and various functionalities through ROP of OCAs are reviewed and evaluated. The in vivo stability, side-chain functionalities, and/or trigger responsiveness of several functional PAHAs are evaluated. Their biomedical applications in drug and gene delivery are also discussed. The ready availability of starting materials from renewable resources and the facile postmodification strategies such as azide-alkyne cycloaddition and the thiol-yne "click" reaction have enabled the production of a multitude of PAHAs with controlled molecular weights, narrow polydispersity, high terminal group fidelities, and structural diversities that are amenable for self-assembly and bioapplications. We anticipate that this new generation of PAHAs and their self-assembled nanosystems as biomaterials will open up exciting new opportunities and have widespread utilities for biological applications.
Collapse
Affiliation(s)
- Qian Yin
- Department
of Materials Science and Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Lichen Yin
- Institute
of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory
for Carbon-Based Functional Materials and Devices and Collaborative
Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, P. R. China
| | - Hua Wang
- Department
of Materials Science and Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Jianjun Cheng
- Department
of Materials Science and Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
42
|
Chao D, Wang S, Tuten BT, Cole JP, Berda EB. Densely Functionalized Pendant Oligoaniline Bearing Poly(oxanorbornenes): Synthesis and Electronic Properties. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b01446] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Danming Chao
- Department of Chemistry and Materials Science Program, University of New Hampshire, Durham, New Hampshire 03824, United States
- Alan G. MacDiarmid Institute, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Shutao Wang
- Alan G. MacDiarmid Institute, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Bryan T. Tuten
- Department of Chemistry and Materials Science Program, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Justin P. Cole
- Department of Chemistry and Materials Science Program, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Erik B. Berda
- Department of Chemistry and Materials Science Program, University of New Hampshire, Durham, New Hampshire 03824, United States
| |
Collapse
|
43
|
Xu Y, Loi J, Delgado P, Topolkaraev V, McEneany RJ, Macosko CW, Hillmyer MA. Reactive Compatibilization of Polylactide/Polypropylene Blends. Ind Eng Chem Res 2015. [DOI: 10.1021/acs.iecr.5b00882] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | - Vasily Topolkaraev
- Kimberly-Clark
Corporation,
Corporate Research and Engineering, Neenah, Wisconsin 54956, United States
| | - Ryan J. McEneany
- Kimberly-Clark
Corporation,
Corporate Research and Engineering, Neenah, Wisconsin 54956, United States
| | | | | |
Collapse
|
44
|
Wang W, Wang W, Li H, Lu X, Chen J, Kang NG, Zhang Q, Mays J. Synthesis and Characterization of Graft Copolymers Poly(isoprene-g-styrene) of High Molecular Weight by a Combination of Anionic Polymerization and Emulsion Polymerization. Ind Eng Chem Res 2015. [DOI: 10.1021/ie504457e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Wenwen Wang
- Key Laboratory
of Applied Physics and Chemistry in Space of Ministry of Education, School of Science, Northwestern Polytechnical University, Xi’an 710072, China
| | - Weiyu Wang
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Hui Li
- Key Laboratory
of Applied Physics and Chemistry in Space of Ministry of Education, School of Science, Northwestern Polytechnical University, Xi’an 710072, China
| | - Xinyi Lu
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Jihua Chen
- Center for
Nanophase
Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Nam-Goo Kang
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Qiuyu Zhang
- Key Laboratory
of Applied Physics and Chemistry in Space of Ministry of Education, School of Science, Northwestern Polytechnical University, Xi’an 710072, China
| | - Jimmy Mays
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| |
Collapse
|
45
|
Gramlich WM. Toughening Polylactide with Phase-Separating Complex Copolymer Architectures. MACROMOL CHEM PHYS 2014. [DOI: 10.1002/macp.201400350] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
46
|
Fang H, Jiang F, Wu Q, Ding Y, Wang Z. Supertough polylactide materials prepared through in situ reactive blending with PEG-based diacrylate monomer. ACS APPLIED MATERIALS & INTERFACES 2014; 6:13552-63. [PMID: 25105468 DOI: 10.1021/am502735q] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Supertough biocompatible and biodegradable polylactide materials were fabricated by applying a novel and facile method involving reactive blending of polylactide (PLA) and poly(ethylene glycol) diacylate (PEGDA) monomer with no addition of exogenous radical initiators. Torque analysis and FT-IR spectra confirm that cross-linking reaction of acylate groups occurs in the melt blending process according to the free radical polymerization mechanism. The results from differential scanning calorimetry, phase contrast optical microscopy and transmission electron microscopy indicate that the in situ polymerization of PEGDA leads to a phase separated morphology with cross-linked PEGDA (CPEGDA) as the dispersed particle phase domains and PLA matrix as the continuous phase, which leads to increasing viscosity and elasticity with increasing CPEGDA content and a rheological percolation CPEGDA content of 15 wt %. Mechanical properties of the PLA materials are improved significantly, for example, exhibiting improvements by a factor of 20 in tensile toughness and a factor of 26 in notched Izod impact strength at the optimum CPEGDA content. The improvement of toughness in PLA/CPEGDA blends is ascribed to the jointly contributions of crazing and shear yielding during deformation. The toughening strategy in fabricating supertoughened PLA materials in this work is accomplished using biocompatible PEG-based polymer as the toughening modifier with no toxic radical initiators involved in the processing, which has a potential for biomedical applications.
Collapse
Affiliation(s)
- Huagao Fang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China , Hefei, Anhui Province 230026, P. R. China
| | | | | | | | | |
Collapse
|
47
|
Xiang S, Zhang Q, Zhang G, Jiang W, Wang Y, Zhou H, Li Q, Tang J. Facile Synthesis of Block Copolymers by Tandem ROMP and eROP from Esters Precursors. Biomacromolecules 2014; 15:3112-8. [DOI: 10.1021/bm500723k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Shidong Xiang
- Department of Polymer Science,
College of Chemistry and ‡Key Laboratory for Molecular Enzymology
and Engineering of Ministry of Education, Jilin University, Changchun 130012, China
| | - Qiuping Zhang
- Department of Polymer Science,
College of Chemistry and ‡Key Laboratory for Molecular Enzymology
and Engineering of Ministry of Education, Jilin University, Changchun 130012, China
| | - Gang Zhang
- Department of Polymer Science,
College of Chemistry and ‡Key Laboratory for Molecular Enzymology
and Engineering of Ministry of Education, Jilin University, Changchun 130012, China
| | - Wei Jiang
- Department of Polymer Science,
College of Chemistry and ‡Key Laboratory for Molecular Enzymology
and Engineering of Ministry of Education, Jilin University, Changchun 130012, China
| | - Yan Wang
- Department of Polymer Science,
College of Chemistry and ‡Key Laboratory for Molecular Enzymology
and Engineering of Ministry of Education, Jilin University, Changchun 130012, China
| | - Hang Zhou
- Department of Polymer Science,
College of Chemistry and ‡Key Laboratory for Molecular Enzymology
and Engineering of Ministry of Education, Jilin University, Changchun 130012, China
| | - Quanshun Li
- Department of Polymer Science,
College of Chemistry and ‡Key Laboratory for Molecular Enzymology
and Engineering of Ministry of Education, Jilin University, Changchun 130012, China
| | - Jun Tang
- Department of Polymer Science,
College of Chemistry and ‡Key Laboratory for Molecular Enzymology
and Engineering of Ministry of Education, Jilin University, Changchun 130012, China
| |
Collapse
|
48
|
Towards high-performance polypropylene and its random copolymer: Insight into toughening mechanism of supercritical carbon dioxide assisted annealing. J Supercrit Fluids 2014. [DOI: 10.1016/j.supflu.2014.01.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
49
|
Delgado PA, Hillmyer MA. Combining block copolymers and hydrogen bonding for poly(lactide) toughening. RSC Adv 2014. [DOI: 10.1039/c4ra00150h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
50
|
Leroux F, Montembault V, Pascual S, Guerin W, Guillaume SM, Fontaine L. Synthesis and polymerization of cyclobutenyl-functionalized polylactide and polycaprolactone: a consecutive ROP/ROMP route towards poly(1,4-butadiene)-g-polyesters. Polym Chem 2014. [DOI: 10.1039/c3py01611k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|