超支化聚酯/端羟基聚丁二烯型聚氨酯互穿网络的固化动力学

通过傅立叶红外光谱,在不同温度下测试了端羟基聚丁二烯(HTPB)型聚氨酯和含有20 %(质量分数)第4代超支化聚酯的HTPB型聚氨酯的固化过程,探索了超支化聚酯的加入对异氰酸酯(NCO)与OH之间反应的影响.结果表明:超支化聚酯的加入对NCO与OH之间的反应有很大的促进作用,反应的活化能由28.3 kJ/mol降低到18.3 kJ/mol,反应均为二级动力学反应.

Curing Kinetics of Hyperbranched Polyester(HBPE)/HTPB Polyurethane IPN by FT-IR

Curing processes of pure HTPB polyurethane and HBPE/HTPB polyurethane IPN were determined by FT-IR at different temperature.The results show that the reaction of HTPB polyurethane and HBPE/HTPB polyurethane IPN all follows the second-order kinetic mechanism.But the reaction rate is enhanced when hyperbranched polyester is introduced.Their activation energies are 28.2 kJ/mol and 18.5 kJ/mol respectively.It is due to the HBPE has Amphiphilic structure which can compatibilizing HTPB and IPDI.Groups of NCO and OH enrich in the "core" part of HBPE.This "core" provides reaction place between NCO and OH,then makes the local concentration of NCO and OH increase,so the reaction rate rises.