Initial Crystallization Effects in Coarse-Grained Polyethylene Systems After Uni- and Biaxial Stretching in Blow-Molding Cooling Scenarios
- This study investigates the initial stage of the thermo-mechanical crystallization behavior for uni- and biaxially stretched polyethylene. The models are based on a mesoscale molecular dynamics approach. We take constraints that occur in real-life polymer processing into account, especially with respect to the blowing stage of the extrusion blow-molding process. For this purpose, we deform our systems using a wide range of stretching levels before they are quenched. We discuss the effects of the stretching procedures on the micro-mechanical state of the systems, characterized by entanglement behavior and nematic ordering of chain segments. For the cooling stage, we use two different approaches which allow for free or hindered shrinkage, respectively. During cooling, crystallization kinetics are monitored: We precisely evaluate how the interplay of chain length, temperature, local entanglements and orientation of chain segments influence crystallization behavior. Our models reveal that the main stretching direction dominates microscopic states of the different systems. We are able to show that crystallization mainly depends on the (dis-)entanglement behavior. Nematic ordering plays a secondary role.
Document Type: | Article |
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Language: | English |
Author: | Dirk Grommes, Martin R. Schenk, Olaf Bruch, Dirk Reith |
Parent Title (English): | Polymers |
Volume: | 14 |
Issue: | 23 |
Article Number: | 5144 |
Number of pages: | 14 |
ISSN: | 2073-4360 |
URN: | urn:nbn:de:hbz:1044-opus-65219 |
DOI: | https://doi.org/10.3390/polym14235144 |
PMID: | https://pubmed.ncbi.nlm.nih.gov/36501539 |
Publisher: | MDPI |
Publishing Institution: | Hochschule Bonn-Rhein-Sieg |
Date of first publication: | 2022/11/26 |
Copyright: | © 2022 by the authors. 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. |
Funding: | Financial support given by the German Federal Ministry of Education and Research within the project “Ressource Optimized Forming” (ROForm, code: 13FH514KX9) is greatly acknowledged. |
Keyword: | biaxial stretching; crystallization; local chain orientation; mesoscale coarse-graining; polyethylene; relaxation |
Departments, institutes and facilities: | Fachbereich Ingenieurwissenschaften und Kommunikation |
Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE) | |
Projects: | FH-Kooperativ 2-2019: Resource Optimized Forming (ROForm) (DE/BMBF/13FH514KX9) |
Dewey Decimal Classification (DDC): | 6 Technik, Medizin, angewandte Wissenschaften / 67 Industrielle Fertigung / 670 Industrielle Fertigung |
Open access funding: | Hochschule Bonn-Rhein-Sieg / Graduierteninstitut |
Hochschule Bonn-Rhein-Sieg / Publikationsfonds / Förderung durch den Publikationsfonds der H-BRS | |
Fields of research: | Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE) / Arbeitsgruppe Computational Chemistry |
Entry in this database: | 2022/11/29 |
Licence (German): | Creative Commons - CC BY - Namensnennung 4.0 International |