Study on Chemical Structures of Tetrafluoroethylene-Perfluoro-Alkyl-Vinylether Copolymer by EB-Irradiation in the Molten State
Perfluorinated polymers such as tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA) with remarkable chemical durability and thermal stability have been applied for industry. However, PFA has been classified to be typical radiation-degradable polymer. In our previous work [1], it has been found that crosslinked PFA has been obtained by irradiation under oxygen-free atmosphere in its molten state. In this study, the change of thermo-physical properties and the chemical structures of crosslinked PFA were studied by DSC and F-NMR. PFA was irradiated by soft electron beam (soft-EB) under nitrogen atmosphere at 583K±3K.
The present invention includes a polyvinyl acetal having a softening temperature Tg of less than 74 ° C., and at least one cyclohexanedicarboxylic acid ester as a plasticizer, a sheet containing a plasticizer. The plasticizer-containing sheets showed slight exudation tendency of plasticizers, combined may be used for the manufacture of glass and the photovoltaic module.