【摘要】 用DSC研究了端羟基聚丁二烯聚氨酯的热氧化反应动力学。结果表明:端羟基聚丁二烯聚氨酯的热氧化反应发生在软段不饱和双键。热氧化反应的温度约470K附近,氧化反应级数接近于2,热氧化反应表观活化能范围约为200～350KJ./mol,氧化反应热在80～200J./g范围内,其中异氰酸酯的种类及扩链剂对其氧化反应有较为明显的影响,具有刚性苯环结构的异氰酸酯和二醇扩链剂可以明显地提高其抗氧化性能。软段分子量对其氧化反应影响不大,且无明显的规律性。更多还原

【Abstract】 This paper studied the kinetics on oxidation of the hydroxyt-terminated poly- butadiene-polyurethane by DSC, discussed that the stucture and content of hard-segment, the molecular weight of soft-segment and the extender et al effected it’s heat-oxidation. The results show that the unsaturational bonds in the soft-segment can cause the heat-oxidation. The temperature of heat oxidation was near 470K, the action order was about 2, the range of the apparent active energy was from 200 to 350 kJ/mol, and the enthalpy range was from 80 to 200 J/g. The kind of the di-isocyanate and the extender effcted the heat-on dation evidently. The di-isocyanate which had stiff benz benzene ring and the dihytric alcohol extender can improve the oxidation- resistance. And it was found that this plyurethane was oxited with cross-linking through the ether bonds and the clevage of urethane bonds.更多还原