Hybrid fluorinated silicones, 2. Synthesis and thermal properties of homopolymers and copolymers

Abstract

The syntheses of various random and alternating copolymers of a fluorosiloxane and a hybrid fluorocarbon-fluorosiloxane are described, and their thermal properties are compared. The parent hybrid homopolymer and the random copolymers were prepared by silanol-chlorosilane condensation, while the alternating copolymers were prepared by silanol/N-bis(acetamidosilane) condensation. The polymers were analysed by 1H, 19F and 29Si NMR spectroscopies and SEC chromatography. The influence of the backbone architecture on their thermal properties was evaluated by DSC and TGA: the copolymers (random or alternating) showed little variation among themselves but slightly better thermal characteristics at low temperature (Tg lowered by about 10 to 15°C) than the parent hybrid homopolymer, whereas the parent homopolymer exhibited higher (≈15°C) stability at high temperature.