Synthesis of epoxide functionalized hyperbranched polyurethane and its blending with benzoxazine: cure kinetics and thermal properties

摘要

Novel epoxide-terminated hyperbranched polyurethanes (EHPU) with different epoxy values were prepared through functionalization of hyperbranched polyurethane with glycidol. Fourier transformed infrared (FTIR) and nuclear magnetic resonance analyses were conducted and confirmed the successfully synthesis of EHPU. Differential scanning calorimetry measurements were carried out for thermal and kinetic studies of EHPU and benzoxazine (BZ) hybrid. Specifically, through kinetic study using advanced isoconversional method, it was found that EHPU can catalyze the polymerization of BZ oligomers when degree of curing is below 0.7 with the apparent activation energy dropped 8.3 kJ/mol. Whereas, the epoxide groups of EHPU can join the curing reaction of BZ at 180 A degrees C, which was further confirmed by FTIR analysis.