DIFFUSION AND PERMEATION OF HYDROBROMIC AND HYDROCHLORIC ACIDS IN PVDF AND ECTFE AT DIFFERENT TEMPERATURES AND CONCENTRATIONS

摘要

Diffusion and permeation can be a major problem when using fluoroplastics in corrosive environments. Sorption and desorption measurements and a new fast indicator technique have been used to obtain more data about the diffusion rates of HCl and HBr in ECTFE, PVDF and PVDF-Flex (PVDF modified with hexafluoropropylene). Data on the influence of the temperature and concentration of the penetrating acid and on the degree of crystallinity of the polymer are presented.