To understand the properties of the fiber reinforced polyimide composite based on 2, 3, 3′, 4′-biphenyl-
tetracarboxcylic anhydride ( a-BPDA) at high temperature,composite samples were preparel using carbon fiber
and quartz fiber as reinforcement. The T5
d decomposition temperature and Tg of composites were 565℃ and 471℃.
The experimental results show that the retention of flexural strength,moduli and interlaminate strength of composites
are 42%,55%,44% at 450℃,respectively;after treated 50 hours at 400℃ in air the retention of flexural strength and
moduli of carbon fiber reinforced composites are 66% and 95%;and the coefficient transmit heat of quartz fiber reinforced
composites at 300℃,500℃ are 0. 503 and 0. 657W/ (m·K)