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

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 H-1, F-19 and Si-29 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 (T-g lowered by about 10 to 15 degrees C) than the parent hybrid homopolymer, whereas the parent homopolymer exhibited higher (approximate to 15 degrees C) stability at high temperature.