Polyvinyl trifluoroacetate

Abstract

Abstract Vinyl trifluoroacetate and its homopolymer have been investigated. In copolymerization, the monomer behaves normally, having a Q similar to that of vinyl acetate and a positive e value resulting from fluorine substitution. Unlike the vinyl acetate system, polyvinyl trifluoroacetate is insoluble in its monomer and polymerization leads to no increase in DP with conversion. It is suspected that substitution of CH 3 by CF 3 has greatly reduced chain transfer and branching. Infrared spectra of vinyl trifluoroacetate and its polymer are presented and solubilities of the latter reported. Polyvinyl trifluoroacetate is very unstable to the hydrolytic loss of the perfluoro acid. The fluoropolymer is much harder than polyvinyl acetate and higher values are obtained for its softening point and apparent second‐order transition temperature. Although no difference can be found by infrared measurements between authentic polyvinyl alcohol and that obtained by hydrolysis of the fluoropolymer, a large difference in their water solubilities exists. Polyvinyl trifluoroacetate is readily oriented by stretching and some polarized infrared absorption data are presented. X‐ray diffraction photographs of stretched specimens indicate moderate order and considerable orientation. These results are surprising when considered in the light of the general concepts regarding polymer structure and crystallinity. Extremely highly ordered and highly birefringent polyvinyl alcohol can be obtained readily from stretched polyvinyl trifluoroacetate by conversion of the latter with gaseous ammonia.