【摘要】 采用原位傅里叶变换红外光谱法,研究了聚酯型聚氨酯和聚醚型聚氨酯在空气气氛中从室温到400℃之间的热解反应,实时考察了其在不同温度条件下分解残留物的基团特性。利用热分析技术考察了它们在不同气氛下从室温到700℃之间的热解反应。探讨了在有氧条件下的热解反应机理。结果表明聚酯型聚氨酯在空气中存在硬段和软段先后分解的两个阶段,而聚醚型聚氨酯则是硬段与软段同时分解。热分解结果也显示,硬段相同的聚氨酯,聚酯型聚氨酯的起始失重温度高于聚醚型聚氨酯,显示聚酯型的热稳定性强于聚醚型。同时聚氨酯在空气中的起始失重温度比在氮气中提前,说明氧气的存在能促进聚氨酯主链上C—C和C—O键的断裂。更多还原

【Abstract】 The thermal behavior of polyester-polyurethane and polyether-polyurethane in air atmosphere was investigated by(using) FTIR analysis in the temperature range from 20 to 400 ℃.The thermal degradation behaviors of polyester-polyurethane and polyether-polyurethane in different atmospheres were investigated by using thermogravimetry analysis(TG) in the temperature range from 20 to 700 ℃.The FTIR results together with the TG investigations showed that polyester-polyurethane has two degradation steps in air,but polyether-polyurethane has only one degradation step.The thermal analysis results also showed that the onset degradation temperature of polyether-polyurethane is lower than that of polyester-polyurethane,suggesting that the thermal stability of polyester-polyurethane is higher than polyether-polyurethane,and the onset degradation temperature of polyurethane in air is lower than that in nitrogen,suggesting that the presence of oxygen affects significantly the break of the polymeric chains.更多还原