2,2‐Bistrifluoromethyl‐4,5‐difluoro‐1,3‐dioxole‐co‐tetrafluoroethylene copolymers with different compositions: Synthesis, chain and condensed matter structures and optical properties

Abstract

Synthesis of 2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxole-co-tetrafluoroethylene (PDD-TFE) copolymers with precise chemical structures and understanding effects of the structures on properties are essential for their application. Herein, PDD-TFE copolymers with different average compositions and narrow composition distributions (NCDs) were synthesized and applied to study the influences of chemical structures on condensed matter structures and optical properties of copolymers. The average length of (P TFE ) n sequences were decreased from 7.62 to 1.63, and percentage of TFE in long (P TFE ) n sequences (n > 5) decreased from approximately 50% to less than 1%, as PDD molar fraction in the copolymer (F PDD ) increased from 13.24% to 52.22%. Consequently, the copolymer with F PDD = 13.24% was semi-crystalline with a crystallinity degree of 11.57% (determined by WAXD),