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Production and Application of Polymer Foams Employing Supercritical Carbon Dioxide. ADVANCES IN POLYMER TECHNOLOGY 2022. [DOI: 10.1155/2022/8905115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Polymeric foams have characteristics that make them attractive for different applications. However, some foaming methods rely on chemicals that are not environmentally friendly. One of the possibilities to tackle the environmental issue is to utilize supercritical carbon dioxide ScCO2 since it is a “green” solvent, thus facilitating a sustainable method of producing foams. ScCO2 is nontoxic, chemically inert, and soluble in molten plastic. It can act as a plasticizer, decreasing the viscosity of polymers according to temperature and pressure. Most foam processes can benefit from ScCO2 since the methods rely on nucleation, growth, and expansion mechanisms. Process considerations such as pretreatment, temperature, pressure, pressure drop, and diffusion time are relevant parameters for foaming. Other variables such as additives, fillers, and chain extenders also play a role in the foaming process. This review highlights the morphology, performance, and features of the foam produced with ScCO2, considering relevant aspects of replacing or introducing a novel foam. Recent findings related to foaming assisted by ScCO2 and how processing parameters influence the foam product are addressed. In addition, we discuss possible applications where foams have significant benefits. This review shows the recent progress and possibilities of ScCO2 in processing polymer foams.
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Recent advances on reactive Extrusion of Poly(lactic acid). Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Dippold M, Ruckdäschel H. Influence of pressure-induced temperature drop on the foaming behavior of amorphous polylactide (PLA) during autoclave foaming with supercritical CO2. J Supercrit Fluids 2022. [DOI: 10.1016/j.supflu.2022.105734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Wang K, Huang YQ, Cheng XH, Yeh JT. Micro foaming performance of scCO 2-aid glutaraldehyde/hexametaphosphate/thermoplastic starch foams modified by alkali treatment and montmorillonite nano-platelets. CELLULAR POLYMERS 2022. [DOI: 10.1177/02624893211073539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The micro foaming performance, moisture resistance and dynamic viscosity of scCO2-aid glutaraldehyde/hexametaphosphate/thermoplastic tapioca starch (GA/SHMP/TOS) foams were considerably improved by proper NaOH treatment. The expansion ratio, resilience rate, dynamic viscosity values of these NaOH modified foams improved to a maximum, as the time for NaOH treatment approached a proper value. The dynamic viscosity, expansion ratio and resilience rate of the scCO2-aid GA/SHMP/TOS foams modified using 110 atm scCO2-pressure, the proper alkali treatment time, SHMP loading and varying montmorillonite (MMT) loadings improved further, as their MMT loadings approached a proper value of 2.5 part per hundred parts of tapioca starch (PHTOS). Relatively large dynamic viscosity (7.1x104 Pa·s), extremely large expansion ratio (∼75), cell density (1.1x109 cells/cm3) and/or resilience rate (∼80%) were acquired for the scCO2-aid GA/SHMP/TOS/MMT foam modified using the proper alkali treatment time and MMT loading. Thermal analyses results showed that crystallization onset temperatures and crystallization rates of scCO2-aid GA/SHMP/TOS/MMT foams modified using the proper alkali treatment time and varying MMT loadings improved to a highest value by adding 2.5 PHTOS of MMT nano-platelets. Possible reasons accounting for the considerably improved micro foaming performance of scCO2-aid GA/SHMP/TOS/MMT foams modified using the proper alkali treatment time and MMT loading are proposed in this study.
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Affiliation(s)
- Ke Wang
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education, Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Faculty of Materials Science and Engineering, Hubei University, Wuhan, China
| | - Ya-qiong Huang
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education, Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Faculty of Materials Science and Engineering, Hubei University, Wuhan, China
| | - Xiao-han Cheng
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education, Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Faculty of Materials Science and Engineering, Hubei University, Wuhan, China
| | - Jen-taut Yeh
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education, Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Faculty of Materials Science and Engineering, Hubei University, Wuhan, China
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Pawłowska A, Stepczyńska M. Natural Biocidal Compounds of Plant Origin as Biodegradable Materials Modifiers. JOURNAL OF POLYMERS AND THE ENVIRONMENT 2022; 30:1683-1708. [PMID: 34720776 PMCID: PMC8541817 DOI: 10.1007/s10924-021-02315-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/15/2021] [Indexed: 05/07/2023]
Abstract
The article presents a literature review of the plant origin natural compounds with biocidal properties. These compounds could be used as modifiers of biodegradable materials. Modification of polymer material is one of the basic steps in its manufacturing process. Biodegradable materials play a key role in the current development of materials engineering. Natural modifiers are non-toxic, environmentally friendly, and renewable. The substances contained in natural modifiers exhibit biocidal properties against bacteria and/or fungi. The article discusses polyphenols, selected phenols, naphthoquinones, triterpenoids, and phytoncides that are natural antibiotics. Due to the increasing demand for biodegradable materials and the protection of the natural environment against the negative effects of toxic substances, it is crucial to replace synthetic modifiers with plant ones. This work mentions industries where materials containing natural modifying additives could find potential applications. Moreover, the probable examples of the final products are presented. Additionally, the article points out the current world's pandemic state and the use of materials with biocidal properties considering the epidemiological conditions.
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Affiliation(s)
- Alona Pawłowska
- Department of Materials Engineering, Kazimierz Wielki University, J.K. Chodkiewicza 30 street, 85-064 Bydgoszcz, Poland
| | - Magdalena Stepczyńska
- Department of Materials Engineering, Kazimierz Wielki University, J.K. Chodkiewicza 30 street, 85-064 Bydgoszcz, Poland
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Standau T, Nofar M, Dörr D, Ruckdäschel H, Altstädt V. A Review on Multifunctional Epoxy-Based Joncryl® ADR Chain Extended Thermoplastics. POLYM REV 2021. [DOI: 10.1080/15583724.2021.1918710] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Tobias Standau
- Department of Polymer Engineering, University of Bayreuth, Bayreuth, Germany
| | - Mohammadreza Nofar
- Metallurgical and Materials Engineering, Department Faculty of Chemical and Metallurgical Engineering, Istanbul Technical University, Maslak, Istanbul, Turkey
- Polymer Science and Technology Program, Institute of Science and Technology, Istanbul Technical University, Maslak, Istanbul, Turkey
| | - Dominik Dörr
- Department of Polymer Engineering, University of Bayreuth, Bayreuth, Germany
| | - Holger Ruckdäschel
- Department of Polymer Engineering, University of Bayreuth, Bayreuth, Germany
| | - Volker Altstädt
- Department of Polymer Engineering, University of Bayreuth, Bayreuth, Germany
- Bavarian Polymer Institute and Bayreuth Institute of Macromolecular Research, University of Bayreuth, Bayreuth, Germany
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Zimnyakov D, Alonova M, Ushakova E. Depressurization-Induced Nucleation in the "Polylactide-Carbon Dioxide" System: Self-Similarity of the Bubble Embryos Expansion. Polymers (Basel) 2021; 13:polym13071115. [PMID: 33915873 PMCID: PMC8036606 DOI: 10.3390/polym13071115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/25/2021] [Accepted: 03/29/2021] [Indexed: 01/28/2023] Open
Abstract
Self-similar expansion of bubble embryos in a plasticized polymer under quasi-isothermal depressurization is examined using the experimental data on expansion rates of embryos in the CO2-plasticized d,l-polylactide and modeling the results. The CO2 initial pressure varied from 5 to 14 MPa, and the depressurization rate was 5 × 10−3 MPa/s. The constant temperature in experiments was in a range from 310 to 338 K. The initial rate of embryos expansion varied from ≈0.1 to ≈10 µm/s, with a decrease in the current external pressure. While modeling, a non-linear behavior of CO2 isotherms near the critical point was taken into account. The modeled data agree satisfactorily with the experimental results. The effect of a remarkable increase in the expansion rate at a decreasing external pressure is interpreted in terms of competing effects, including a decrease in the internal pressure, an increase in the polymer viscosity, and an increase in the embryo radius at the time of embryo formation. The vanishing probability of finding the steadily expanding embryos for external pressures around the CO2 critical pressure is interpreted in terms of a joint influence of the quasi-adiabatic cooling and high compressibility of CO2 in the embryos.
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Affiliation(s)
- Dmitry Zimnyakov
- Physics Department, Yury Gagarin State Technical University of Saratov, 410054 Saratov, Russia; (M.A.); (E.U.)
- Precision Mechanics and Control Institute of Russian Academy of Sciences, 24 Rabochaya st., 410024 Saratov, Russia
- Correspondence: ; Tel.: +7-845-299-8624
| | - Marina Alonova
- Physics Department, Yury Gagarin State Technical University of Saratov, 410054 Saratov, Russia; (M.A.); (E.U.)
| | - Ekaterina Ushakova
- Physics Department, Yury Gagarin State Technical University of Saratov, 410054 Saratov, Russia; (M.A.); (E.U.)
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Rheological, Mechanical and Morphological Characterization of Fillers in the Nautical Field: The Role of Dispersing Agents on Composite Materials. Polymers (Basel) 2020; 12:polym12061339. [PMID: 32545645 PMCID: PMC7361945 DOI: 10.3390/polym12061339] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/09/2020] [Accepted: 06/09/2020] [Indexed: 11/16/2022] Open
Abstract
Coatings have a fundamental role in covering the external surface of yachts by acting both as protective and aesthetic layers. In particular, fillers represent the essential layer from the point of view of mechanical properties and consist of a polymeric matrix, different extenders and additives, and dispersing agents, with the latter having the role to provide good extender-matrix compatibility. In the present work, the effects of dispersing agents with an ionic or steric action on the interactions between hollow glass microspheres and an epoxy-polyamide resin are evaluated. Un-crosslinked filler materials are studied via rheological tests, whereas the mechanical and morphological properties of the crosslinked samples are assessed. The results clearly indicate that steric dispersing agents provide a much greater compatibility effect compared to ionic ones, owing to their steric hindrance capability, thus leading to better-performing filler materials with a less-marked Payne effect, which is here proved to be an efficient tool to provide information concerning the extent of component interactions in nautical fillers. To the best of our knowledge, this work represents the first attempt to deeply understand the role of dispersing agents, which are until now empirically used in the preparation of fillers.
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