Novel bismaleimide/diallylbisphenol A resin modified with multifunctional thiol containing isocyanuric ring and long-chain aliphatic unit

Abstract

4,4′-Diphenylmethane bismaleimide (BMI)/2,2′-diallylbisphenol A (DABPA) resin was modified with a multifunctional thiol containing isocyanuric ring and long-chain aliphatic unit (tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate (TEMPIC)). To investigate the relationship of the curing reaction and properties of cured BMI/DABPA resin modified with TEMPIC, the temporal change in the functional groups during the curing reaction process was analyzed using Fourier transform infrared analysis. Despite the decreased cross-link density with increasing TEMPIC concentration, the glass transition temperature of BMI/DABPA resin was not decreased by modification with TEMPIC. The storage modulus of BMI/DABPA/TEMPIC resin maintained a value on the order of 109 Pa in the rubber region, which is similar to that of the unmodified resin. The fracture toughness and flexural strength were also improved by modification with TEMPIC. Moreover, the observation of the fracture surface of BMI/DABPA/TEMPIC resin using scanning electron microscopy showed a uniform structure with no phase separation. These results were consistent with the single α-relaxation peak in the loss tangent curve of the dynamic viscoelastic behavior.