The morphological changes and improvement of membrane properties caused by heat treatment were investigated for polytetrafluoroethylene (PTFE) porous membranes prepared from a fine powder by extrusion, rolling and stretching. The properties of the membrane were significantly changed by heat treatment at temperatures higher than 320°C. Shrinkage diminished and the mechanical strength increased due to the partial melting of PTFE. The increase in mechanical strength was caused by suppression of new fibril formation as a result of the loss of folded ribbon‐like crystalline structures that facilitated fibril structures to be pulled out of the original PTFE particle. The decrease in shrinkage was caused by the transformation of fibrils, formed as a collection of ribbon‐like structures, into a massive fibrous structure, which inhibited the reformation of particles. The most important change of the porous structure caused by the heat treatment was the union of nodes in the direction of stretching resulting in a PTFE porous membrane with larger spatial periodicity. A heat treatment above melting temperature of PTFE was the most effective. However, it was necessary to control the temperature and time in order to restrict the coarseness of the porous structure of the membrane.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.