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Material Characterization of Polypropylene and Polystyrene Regarding Molecular Degradation Behavior

During the processing of thermoplastics, polymers are subjected to high stress. As a result of this stress, the polymer chains break, leading to a lower molar mass. This further leads to a lower viscosity of the plastic melt and, eventually, to poorer mechanical properties of the manufactured plasti...

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Autores principales: Schall, Christoph, Schöppner, Volker
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10488556/
https://www.ncbi.nlm.nih.gov/pubmed/37687584
http://dx.doi.org/10.3390/ma16175891
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author Schall, Christoph
Schöppner, Volker
author_facet Schall, Christoph
Schöppner, Volker
author_sort Schall, Christoph
collection PubMed
description During the processing of thermoplastics, polymers are subjected to high stress. As a result of this stress, the polymer chains break, leading to a lower molar mass. This further leads to a lower viscosity of the plastic melt and, eventually, to poorer mechanical properties of the manufactured plastic product. Especially in the context of recycling plastics, this poses a challenge to process technology and product properties. This work aims is to provide a prediction of the material degradation under known stress, so that, for example, a process design that is gentle on the material can be carried out. In order to be able to predict material degradation under a load, a test stand for defined material degradation was designed. The test stand allows for material damaging under a defined temperature, shear rate and residence time. At the same time, the test stand can be used to measure the viscosity, which is used to describe the degradation behavior, since the viscosity correlates with the molar mass. The measured decrease in viscosity under stress can be used to predict material damage under the influencing variables of temperature, shear rate and residence time by means of a test plan and a suitable mathematical description of the measured data. The mathematical description can thus be integrated into simulation environments for plastics processing, so that a simulation of the material degradation can be carried out, if necessary also taking the viscosity reduction into account.
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spelling pubmed-104885562023-09-09 Material Characterization of Polypropylene and Polystyrene Regarding Molecular Degradation Behavior Schall, Christoph Schöppner, Volker Materials (Basel) Article During the processing of thermoplastics, polymers are subjected to high stress. As a result of this stress, the polymer chains break, leading to a lower molar mass. This further leads to a lower viscosity of the plastic melt and, eventually, to poorer mechanical properties of the manufactured plastic product. Especially in the context of recycling plastics, this poses a challenge to process technology and product properties. This work aims is to provide a prediction of the material degradation under known stress, so that, for example, a process design that is gentle on the material can be carried out. In order to be able to predict material degradation under a load, a test stand for defined material degradation was designed. The test stand allows for material damaging under a defined temperature, shear rate and residence time. At the same time, the test stand can be used to measure the viscosity, which is used to describe the degradation behavior, since the viscosity correlates with the molar mass. The measured decrease in viscosity under stress can be used to predict material damage under the influencing variables of temperature, shear rate and residence time by means of a test plan and a suitable mathematical description of the measured data. The mathematical description can thus be integrated into simulation environments for plastics processing, so that a simulation of the material degradation can be carried out, if necessary also taking the viscosity reduction into account. MDPI 2023-08-28 /pmc/articles/PMC10488556/ /pubmed/37687584 http://dx.doi.org/10.3390/ma16175891 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Schall, Christoph
Schöppner, Volker
Material Characterization of Polypropylene and Polystyrene Regarding Molecular Degradation Behavior
title Material Characterization of Polypropylene and Polystyrene Regarding Molecular Degradation Behavior
title_full Material Characterization of Polypropylene and Polystyrene Regarding Molecular Degradation Behavior
title_fullStr Material Characterization of Polypropylene and Polystyrene Regarding Molecular Degradation Behavior
title_full_unstemmed Material Characterization of Polypropylene and Polystyrene Regarding Molecular Degradation Behavior
title_short Material Characterization of Polypropylene and Polystyrene Regarding Molecular Degradation Behavior
title_sort material characterization of polypropylene and polystyrene regarding molecular degradation behavior
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10488556/
https://www.ncbi.nlm.nih.gov/pubmed/37687584
http://dx.doi.org/10.3390/ma16175891
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