Studies on thermal and morphological behavior of Siliconized Epoxy Bismaleimide Matrices

Novel bismaleimide-modified siliconized epoxy intercrosslinked network systems were developed. Siliconized epoxy systems containing 5, 10, and 15% siloxane units were prepared using epoxy resin and hydroxyl-terminated polydimethylsiloxane13; (HTPDMS) with y-aminopropyltriethoxysilane (y-APS) as a compatibilizer and dibutyltindilaurate as a catalyst. The siliconized epoxy systems were further modified with 5, 10, and 15% (wt %) of bismaleimide [(N,N' -bismaleimido-4,4' -dipherlylmethane) (BMD] and cured by diaminodiphenylmethane (DDM). Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and heat-distortion temperature measurement of the matrix samples were carried out to assess their thermal behavior. DSC thermograms of the EMI-modified epoxy systems show unimodel reaction exotherms. The glass thermal transition (Tr) of the cured BMI-modified epoxy and siliconized epoxy systems increases with increasing BMI content. Thermo'gravimetric analysis and heat-distortion temperature measurements indicate that the thermal degradation temperature and heat-distortion temperature of the EMI-modified epoxy and siliconized epoxy systems increase with increasing BMI content. The morphology of the BMI modified siliconized epoxy systems was also studied by scanning electron microscop