Novel thermosetting resin with a very high glass-transition temperature based on bismaleimide and allylated novolac

Thermosetting resin systems with very high glass-transition temperatures were formulated on the basis of bismaleimide and allylated novolac (BMAN). When the allylation degree of the novolac resin was high enough, the bismaleimide (BMI) proportion was not critical to the heat resistance of the cured resin. The BMAN15 resin with a high allylation degree and a low BMI proportion was appropriate for resin-transfer molding. Composites of BMAN15, with quartz woven cloth as reinforcement showed good strength and modulus retention rates at 350 degrees C. The curing of the BMAN15 resin was illustrated by Fourier transform infrared and differential scanning calorietry studies. It turned out that allyl groups participated via ene reaction and the Diels-Alder reaction, as the maleimide groups did, forming a densely crosslinked structure in the cured resin. (c) 2005 Wiley Periodicals,