Synthesis and properties of copolymers of poly(ether ketone ketone) and poly(ether amide ether amide ether ketone ketone)

摘要

Poly(aryl ether ketone)s (PAEKs) are a class of high-performance engineering thermoplastics known for their excellent combination of chemical, physical and mechanical properties, and the synthesis of semicrystalline PAEKs with increased glass transition temperatures (T_g) is of much interest. In the work reported, a series of novel copolymers of poly(ether ketone ketone) (PEKK) and poly(ether amide ether amide ether ketone ketone) were synthesized by electrophilic solution polycondensation of terephthaloyl chloride with a mixture of diphenyl ether and N,N'-bis(4-phenoxybenzoyl)-4,4'-diaminodiphenyl ether (BPBDAE) under mild conditions. The copolymers obtained were characterized using various physicochemical techniques. The copolymers with 10-35 mol% BPBDAE are semicrystalline and have markedly increased T_g over commercially available poly(ether ether ketone) and PEKK due to the incorporation of amide linkages in the main chain. The copolymers with 30-35 mol% BPBDAE not only have high T_g of 178-186 °C, but also moderate melting temperatures of 335-339 °C, having good potential for melt processing. The copolymers with 30-35 mol% BPBDAE have tensile strengths of 102.4-103.8 MPa, Young's moduli of 2.33-2.45 GPa and elongations at break of 11.7-13.2%, and exhibit high thermal stability and good resistance to organic solvents.