Synthesis and characterization of cyclohexyl-containing poly(ether ketone sulfone)s

A series of poly(ether ketone sulfone)s were synthesized from 1,4-di(fluorobenzoyl)cyclohexane, difluorodiphenylsulfone and bisphenol A. These polymers were characterized by NMR, IR, SEC, DSC, TGA, tensile tests and DMA. The results from NMR, IR, and SEC indicated that essentially no side reactions, such as cross-linking, associated with enolate chemistry take place during the polymerizations although cis/trans stereochemistry inversion was observed. Comparison of the T_gs of the polymers with 1,4-cyclohexyl units to those of the terephthaloyl analogs suggested that the trans-1,4-cyclohexyl imparts slightly higher T_g than the terephthaloyl control. Tensile tests and DMA revealed that polymers with 1,4-cyclohexyl have essentially the same storage moduli as the corresponding aromatic analogs despite the inherent flexibility of the cyclohexyl unit. DMA also showed that the cyclohexyl unit imparts a larger magnitude of sub-T_g motion than terephthaloyl unit while maintaining high modulus.