Synthesis and Characterization of Poly(ethylene terephthalamide/hexamethylene terephthalamide)

Semiaromatic poly(ethylene terephthalamide/hexamethylene terephthalamide) copolymer (PA2T/6T) was synthesized through the reaction of terephthaloyl chloride, 1,6-hexane diamine and 1,2-ethylene diamine by the method of interfacial polycondensation. The inherent viscosities of the resultant copolymers prepared with optimum synthesis conditions were 0.40–0.80 dL/g. The chemical structures of the copolymers were characterized by FT-IR and 1H-NMR. These copolymers had excellent thermal properties with melting temperatures (Tm) of 340–380°C and initial degradation temperatures (Td) of 390–440°C. The copolymers had wider processing temperature range than poly(hexamethylene terephthalamide) (PA6T), especially the copolymer which contained 60% 2T unit (2T mol% = 60%). At the same time, the ethylene diamine and hexane diamine is cheap which can decrease the costs of the materials. It suggests PA2T/6T is a promising heat resistant and processable engineering plastic.