Fabrication of high-performance copolyimide fibers from 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine and 2-(4-aminophenyl)-6-amino-4(3H)-quinazolinone

Abstract

High-performance copolyimide (co-PI) fibers synthesized by 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), p-Phenylenediamine (p-PDA) and 2-(4-aminophenyl)-6-amino-4(3H)-quinazolinone (AAQ) were prepared via a two-step spinning technology. The influences of the thermal treatment temperatures on the structure, and mechanical and thermal properties of the co-PI fibers were studied. The co-PI fibers with excellent mechanical and thermal properties were obtained by heating the co-PAA fibers under a drawing ratio of 1.05 at 240°C and subsequently at 390°C. The tensile strength and modulus reach 2.6GPa and 112.3GPa, respectively. The 5%-weight-loss temperatures of the co-PI fibers under nitrogen and air achieve 611°C and 565°C, respectively, and the glass transition temperature is over 400°C.