Mechanical and optical properties of the copolymers of perfluoro(2-methylene-4-methyl-1,3-dioxolane) and chlorotrifluoroethylene

Aiming at improving the flexibility of polymer films, the copolymers of perfluoro(2-methylene-4-methyl-1,3-dioxolane) (PFMMD) and chlorotrifluoroethylene (CTFE) with different compositions were prepared by radical polymerization using perfluorobenzoyl peroxide (PFBP) as the initiator, and their thermal, mechanical, and optical characteristics were investigated. These copolymers are amorphous, soluble in fluorinated solvents, with glass transition temperatures (To) in the range of 100-135 degrees C, and thermally stable to near 400 degrees C. Stress-strain curves of polymer films were obtained and tensile strength as well as Young's modulus were calculated. Film flexibility and elongation are improved with increasing fraction of UTE in the copolymers. The copolymer films have low refractive indices (1.33-1.40) and exhibit extraordinary optical transmittance within the visible and near-infrared regions. The copolymers are promising materials for applications including plastic optical fibers, waveguides, and anti-reflective coating.