Synthesis and properties of poly(aryl ether ketone) copolymers with trifluoromethyl-substituted benzene in the side chain

摘要

The new monomer (4-(4'-trifluoromethyl)phenoxyphenyl)hydroquinone (TFPOPH) was synthesized in a three-step synthesis. A series of poly(aryl ether ketone) copolymers were prepared by the reaction of (4-(4'-Trifluoromethyl)phenoxyphenyl)hydroquinone and hydroquinone (HQ) with 4,4'-difluorobenzophenone (DFB) in the presence of potassium carbonate in tretramethylene sulfone (TMS). Thermal analyses of the fluorinated copolymers showed that the glass transition temperature and 5.0% weight loss temperature are similar with that of PEEK, and the crystallinity decreased with increasing of TFPOPH. For the copolymer synthesized with the molar fraction of TFPOPH in the diphenol monomers (TFPOPH, HQ) being over 0.2, no cold crystallization temperature and melting temperature were detected, indicating that these copolymers are almost amorphous. The crystal structure of the copolymers with the molar fraction of TFPOPH being not higher than 0.2 is rhombic. The solubility in polar aprotic solvents of poly(aryl ether ketone)s copolymers increases and dielectric constant decreases step by step.