Thermal degradation study of interpenetrating polymer network based on modified bismaleimide resin and cyanate ester

Interpenetrating polymer networks (IPNs) based on different ratios of a modified bismaleimide resin (BMI/DBA) and cyanate ester (W) have been synthesized via prepolymerization followed by thermal curing. A systematic thermal degradation study of these new BMI/DBA-CE IPN resin systems was conducted by thermogravimetric analysis at different heating rates both in N-2 (thermal stability) and in air (thermal-oxidative stability). The cured BMI/DBA-CE IPN resin systems show excellent thermal stability, which could be demonstrated by 5% weight loss temperature (T-5%) ranging between 409 and 423degreesC, maximum decomposition rate temperature (T-max) ranging between 423 and 451degreesC, and the char yields at 800degreesC ranging from 37% to 41% in nitrogen at a heating rate of 10degreesC min(-1). The apparent activation energy associated with the main degradation stage of the cured BMI/DBA-CE IPN resin systems was determined using the Kissinger method. The obtained results provide useful information in drawing correlation between thermal properties and structure. (C) 2003 Society of Chemical Industry.