Resin transfer molding and resin infusion fabrication of high-temperature composites

Resin transfer molding (RTM) and resin infusion (RI) are cost-effective processes for the fabrication of composite parts, particularly support structures such as frames and spars, As part of the high-speed research (HSR) program to develop technology for a Mach 2.4 high-speed civil transport with performance requirements for long term at 177 degrees C, phenylethynyl containing imide oligomers were developed for RTM and RI fabrication of composite parts. Two of these new materials, designated PETI-RTM and RFI, exhibited low-melt viscosity (similar to 0.1 - 1.0 Pa.s) at 260-280 degrees C with exceptional melt stability (>4 hours). The cured resins and their composites had high glass transition temperatures (Tgs), acceptable toughness, and good mechanical properties. The chemistry, mechanical, and physical properties of the resins, fabrication, and properties of composites via RTM and RI are discussed.