Synthesis and Characterization of Bismaleimide (1,3-bismaleimido benzene) – Vinyl Ester Oligomer Modified Unsaturated Polyester Interpenetrating Matrices

Abstract

Bismaleimide - vinyl ester oligomer modified unsaturated polyester interpenetrating network systems were developed. Unsaturated polyester was modified with 10%, 20%, 30% (by wt) of vinyl ester oligomer with benzoyl peroxide as curing agents. The vinyl ester oligomer toughened unsaturated polyester matrix systems were further modified with 5%, 10% and 15% (by wt.) of 1,3-bismaleimido benzene. Thermal behaviour of the matrices were characterised by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and heat deflection temperature analysis. Mechanical properties were studied by ASTM methods. Data obtained from mechanical and thermal studies indicated that the introduction of vinyl ester oligomer into unsaturated polyester improves the fracture toughness with marginal reduction in the values of heat deflection temperature, and glass transition temperature. However, the introduction of BMI into VEO incorporated unsaturated polyester resin enhanced both thermal and mechanical behaviour of unsaturated polyester resin.