Curing kinetics and mechanical properties of cyanate ester/hyperbranched benzoxazine copolymers

In the current study, three different curing kinetics models were used to analyze the curing kinetics of hyperbranched benzoxazine (HB-PED230) and monofunctional benzoxazine (P-a) modified cyanate ester (CE) resin by non-isothermal differential scanning calorimeter. Moreover, the effects of two benzoxazines on the copolymerization behavior, thermal stability, and mechanical properties of CE resin were studied. Compared with the P-a modified CE resin, HB-PED230 greatly reduces the curing temperature of the copolymer, while improving the bending strength and impact strength. The curing temperature of HB-PED230 modified CE resin was 79 degrees C lower than neat CE resin, while the CE/P-a blended resin only reduce 48 degrees C. As the amount of HB-PED230 increased, the flexural strength and flexural modulus of the copolymers were improved. Surprisingly, when 7 wt% of HB-PED230 was added, the impact strength of the copolymer was increased by 177.6%, implying that the toughness of CE resin had been greatly improved. Moreover, the fracture morphology of the copolymers was observed by scanning electron microscope. In summary, a small amount of HB-PED230 blending can effectively improve the overall performance of CE resin.

Automated summary

The study found that blending a small amount of HB-PED230 can effectively reduce the curing temperature of CE resin, while improving the bending strength and impact strength. Additionally, it was observed that as the amount of HB-PED230 increased, the flexural strength and flexural modulus of the copolymers were improved.