Mechanical and thermal properties of perfluoroalkyl ethyl methacrylate–methyl methacrylate statistical copolymers synthesized in supercritical carbon dioxide

Abstract

Abstract Poly(methyl methacrylate-ran-perfluoroalkyl ethyl methacrylate) copolymers having varying perfluoroalkyl ethyl methacrylate ester (Zonyl-TM) contents were synthesized in supercritical CO 2 . Complete amorphous structures of the copolymers were verified by XRD. Young's modulus ( Y mod ) of the copolymers was decreased linearly from 1.57 to 1.08 GPa and T g values from 102 to 77 °C with the increase of Zonyl-TM content. A linear relationship between the Y mod and the T g values of the copolymer was also found. The increase of the large branched pendant groups resulted in the increase of the free volume and a corresponding decrease in Y mod and T g of the copolymers. A good fit was found when the Schneider equation was used. Negative deviation from the Gordon–Taylor equation was observed when Zonyl-TM content was lower than 14% due to rapid increase in free volume and then a positive deviation was found due to the dipole–dipole interactions between the methyl ester and fluoroalkyl ester groups.