Crosslinking of poly(vinyl chloride) - I. Grafting of vinyltri(alkoxy)silanes using UV irradiation

摘要

In a nitrogen atmosphere the UV irradiation of thin PVC films (ca. 0.1 mm thick) containing vinyltri(isopropoxy)silane results in a grafting reaction. By appropriate choice of conditions, dehydrochlorination can be kept to a minimum while up to 60% gel content is realized. Reaction of the pendent alkoxy groups, either with HCl byproduct or subsequent hydrolysis by exposure to water, results in the formation of Si-O-Si bonds that serve as chemical crosslinks, Although the addition of photosensitizers favors the grafting reactions at short exposure times, the ultimate level of crosslinking is greatly diminished by their presence. (C) 1998 John Wiley & Sons, Inc. [References: 23]