Optimization of Liquid Molding Cycle for a Phenylethynyl Terminated Polyimide Composite

ABSTRACT: This article presents a robust resin transfer molding (RTM) process window of a phenylethynyl terminated imide (PETI) oligomer with melt viscosity lower than 1 Pa s over 15min and 10 Pa s for 2 h at 280C. Curing occurs rapidly only above 350C. Curing should be over 30min at 370C. Molding optimization reduces the melt viscosity. The oligomer is heated rapidly from 265 to 280C for the minimum viscosity being lower. The melt is further heated for easier flow in injection and early permeation. The mechanical properties of the prepared composite remain almost constant up to 280C, facilitating the fabrication of large, complex, high-quality aerospace parts. KEY WORDS: imide oligomer, polymer-matrix composites, curing, resin transfer molding