Influence of Allyl Groups on the Reaction of Maleimide with Benzoxazine and the Cured Properties

Abstract

The glass transition temperature (T_g) and coefficient of thermal expansion (CTE) of cured resin obtained by thereaction of cresol novolac type maleimide resin and bisbenzoxazine with allyl groups were measured. Cured resin obtained under curing conditions of 2 h at 220 ℃ showed a T_g above 350 ℃ and a CTE of 49–52 ppm/K. These values were higher thermal resistance and lower thermal expansion compared to a cured resin using benzoxazine without an allyl group.Reaction analysis using monofunctional model compounds suggested that the cycloaddition products were obtained by the reaction of a benzoxazine degradate with maleimide. The peroxide-catalyzed reaction consumed more allyl groups than the imidazole-catalyzed one, which suggests the peroxide-catalyzed resin has higher cross-linking density.