Synthesis, characterization, and crystallization of thermoplastic aromatic semi-crystalline poly(ester-imide)s based on bis(trimellitic acid anhydride) phenyl ester

摘要

A high molecular weight aromatic homopoly(ester-imide) (homoPEI) was synthesized from homopoly(ester-amic acids) (homoPEAA), which was obtained from the reaction of bis(trimellitic acid anhydride) phenyl ester (BTAH) with 4-4'-oxydianiline ether (ODA). This homoPEI was melt-processable semi-crystalline polymer and displayed dual endothermic transitions which were attributed to the different levels of crystal perfection and size in the crystal structures. Four high molecular weight aromatic copoly(ester-imide)s (coPEIs) were synthesized via copoly(ester-amic acids)s (coPEAA) from the reaction of 4, 4'-oxydiphthalic anhydride (ODPA) and BTAH with ODA. The molar percentage of BTAH varied from 10 to 40%. When the molar percentages of BTAH were 30 and 40%, the resulting two coPEIs were crystallinable and their melting temperatures were 361℃ and 356/371℃, respectively. Differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD) results indicated that the crystal structures included short segments of BTAH/ODA and ODPA/ODA. The initial crystallization of the two coPEIs took place during imidization process. Thermogravimetric (TA) and mechanical analysis confirmed that both homoPEI and coPEIs showed almost no weight loss until 400℃ in N_2 and good mechanical properties.