{"title":"Structural evolution of low-entangled UHMWPE gel films with reserved shish crystals and different entanglement degrees during stretching","authors":"","doi":"10.1016/j.polymer.2024.127592","DOIUrl":null,"url":null,"abstract":"<div><p>Shish-kebab crystal is a crucial crystalline morphology in polymers, and its formation and evolution are paramount for achieving high-performance materials. In this study, using UHMWPE as an example, we employed precise temperature control in the gel molding process to prepare low-entangled UHMWPE gel films containing reserved shish crystals, Distinguished from other molding systems, gel molding, due to the presence of small-molecule solvents, not only reduces the entanglement degree of the system but also provides a favorable environment for molecular chain disentanglement, and thus is considered as a low-entanglement system that is easily disentangled. We investigated the structural evolution of the films at different stretching temperatures by employing in-situ WAXD, SAXS, USAXS, along with ex-situ SEM and DSC methods. Furthermore, the impact of entanglement degree on the evolution of crystal structures was explored through the change of molecular weight. 2D-USAXS results reveal the longer stripe scattering signals than previous studies, indicating a more pronounced ordered arrangement of shish crystals. Simultaneously, we discovered that only when molecular chains with an appropriate degree of entanglement were induced to disentangle by stretching with the presence of small-molecule solvents can the high orientation of crystals be facilitated, thereby promoting the evolution of crystal structure. Reserved shish crystals can induce crystal orientation during stretching and facilitate structural evolution. Building upon earlier investigations, this study innovatively through the dual-factor (the molecular weight and stretching temperature) control of the suitable entanglement degree and disentanglement conditions, allowing for reasonable control of the growth and evolution of shish-kebab crystals in low-entangled systems.</p></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Polymer","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0032386124009285","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
Shish-kebab crystal is a crucial crystalline morphology in polymers, and its formation and evolution are paramount for achieving high-performance materials. In this study, using UHMWPE as an example, we employed precise temperature control in the gel molding process to prepare low-entangled UHMWPE gel films containing reserved shish crystals, Distinguished from other molding systems, gel molding, due to the presence of small-molecule solvents, not only reduces the entanglement degree of the system but also provides a favorable environment for molecular chain disentanglement, and thus is considered as a low-entanglement system that is easily disentangled. We investigated the structural evolution of the films at different stretching temperatures by employing in-situ WAXD, SAXS, USAXS, along with ex-situ SEM and DSC methods. Furthermore, the impact of entanglement degree on the evolution of crystal structures was explored through the change of molecular weight. 2D-USAXS results reveal the longer stripe scattering signals than previous studies, indicating a more pronounced ordered arrangement of shish crystals. Simultaneously, we discovered that only when molecular chains with an appropriate degree of entanglement were induced to disentangle by stretching with the presence of small-molecule solvents can the high orientation of crystals be facilitated, thereby promoting the evolution of crystal structure. Reserved shish crystals can induce crystal orientation during stretching and facilitate structural evolution. Building upon earlier investigations, this study innovatively through the dual-factor (the molecular weight and stretching temperature) control of the suitable entanglement degree and disentanglement conditions, allowing for reasonable control of the growth and evolution of shish-kebab crystals in low-entangled systems.
期刊介绍:
Polymer is an interdisciplinary journal dedicated to publishing innovative and significant advances in Polymer Physics, Chemistry and Technology. We welcome submissions on polymer hybrids, nanocomposites, characterisation and self-assembly. Polymer also publishes work on the technological application of polymers in energy and optoelectronics.
The main scope is covered but not limited to the following core areas:
Polymer Materials
Nanocomposites and hybrid nanomaterials
Polymer blends, films, fibres, networks and porous materials
Physical Characterization
Characterisation, modelling and simulation* of molecular and materials properties in bulk, solution, and thin films
Polymer Engineering
Advanced multiscale processing methods
Polymer Synthesis, Modification and Self-assembly
Including designer polymer architectures, mechanisms and kinetics, and supramolecular polymerization
Technological Applications
Polymers for energy generation and storage
Polymer membranes for separation technology
Polymers for opto- and microelectronics.