LOW-MELT VISCOSITY POLYIMIDE RESINS FOR RESIN TRANSFER MOLDING (RTM) II

摘要

A series of polyimide resins with low-melt viscosities in the range of 10-30 poise and high glass transition temperatures (T_(g)'s) of 330-370 deg C were developed for resin transfer molding (RTM) applications. These polyimide resins were formulated from 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA) with 4-phenylethynylphthalic anhydride endcaps along with either 3,4'-oxyaniline (3,4'-ODA), 3,4'-methylenedianiline, (3,4'-MDA) or 3,3'-methylenedianiline (3,3'-MDA). These polyimides had pot lives of 30-60 minutes at 260-280 deg C, enabling the successful fabrication of T650-35 carbon fiber reinforced composites via RTM process. The viscosity profiles of the polyimide resins and the mechanical properties of the polyimide carbon fiber composites will be discussed.