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

Resin transfer molding (RTM) and resin infusion (RI) are cost-effective pro cesses for the fabrication of composite parts, particularly support structu res such as frames and spars, As part of the high-speed research (HSR) prog ram to develop technology for a Mach 2.4 high-speed civil transport with pe rformance requirements for long term at 177 degrees C, phenylethynyl contai ning 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 ex ceptional melt stability (>4 hours). The cured resins and their composites had high glass transition temperatures (Tgs), acceptable toughness, and goo d mechanical properties. The chemistry, mechanical, and physical properties of the resins, fabrication, and properties of composites via RTM and RI ar e discussed.