Mechanical, optical and gas transport properties of poly(perfluoro-2-methylene-4-methyl-1,3-dioxolane) membrane containing perfluoropolyether as a plasticizer

To improve the flexibility of poly(perfluoro-2-methylene-4-methyl-1,3-dioxolane), perfluoropolyether was added as a plasticizer to the dioxolane polymer. The glass transition temperature (T-g) of the polymer/plasticizer blend is in the range of 125-130 degrees C, which is slightly lower compared to that of pure dioxolane polymer due to the addition of perfluoropolyether. The blended polymers have low refractive index (1.328-1.333) and exhibited extraordinary optical transmittance within the visible and near-infrared regions. Stress-strain curves of polymer blend films were obtained, and tensile strength as well as Young's modulus were calculated. Film flexibility and elongation were improved significantly by the addition of the perfluoropolyether. These enhanced mechanical properties could be beneficial for potential applications of the perfluoropolymers such as plastic optical fibers and gas separation membranes. Membranes made from the perfluoropolymer/plasticizer blends show increased permeances for gases (CH4, N-2, H-2, CO2) and slightly reduced gas selectivities as the amount of perfluoropolyether is increased.