High performance bismaleimide/cyanate ester hybrid polymer networks with excellent dielectric properties

A high performance resin system with good dielectric properties for resin transfer molding (RTM), HERTM, was developed. HERTM is a hybrid polymer network based on o,o'-diallyl bisphenol A modified 4,4'-bismaleimidodiphenylmethane, and 1,1'-bis(4-cyanatophenyl)ethane. The processing characteristics, thermal, mechanical and dielectric properties of the system were studied, and the effect of differing stoichiometry of each component on the processing and performance parameters was discussed. Investigations show that the processing properties of the HERTM system was greatly depended on the stoichiometry of each component in formulations, while all the three formulations developed in this paper have good processing characteristics such as low viscosity (220-411 cps) at 90 degrees C, suitable pot life (> 4 h) and good reactivity, and thus meet the needs of RTM technique. The cured HERTM system possesses excellent dielectric properties, much lower dielectric constant and dielectric loss than present commercially available bismaleimide systems. In addition, HERTM system exhibits very good thermal properties (glass transition temperature T-g similar to 300 degrees C) and good mechanical properties, suggesting that HERTM system has great potential to be used as a matrix for advanced structural/functional composites. (c) 2005 Elsevier Ltd. All rights reserved.