聚醚型水性聚氨酯热分解动力学的研究

摘要

The title waterborne polyurethane was prepared from polyether N -210 by acetone process. The kinetics of thermal degradations of waterborne polyether polyurethane in air and nitrogen atmospheres were investigated by thermogravimetry analysis (TG). The kinetic parameters of thermal degradation of waterborne polyurethanes, including activation energy and pre - exponential factors, were obtained with the "model free method". The results showed that the thermal decomposition process could be divided into two steps. The first - stage was degradation of hard segment, and the second - stage was degradation of soft segment. The presence of oxygen would affect significantly the break of the polymeric C-C and C-0 bonds.%以聚醚N-210为原料,利用丙酮法合成了水性聚氨酯,使用热重分析技术考察了聚醚型水性聚氨酯分别在氮气条件和氧气条件下的热稳定性,并采用“无模式法”研究了在不同气氛氛围下的热分解动力学,同时计算了不同热分解阶段反应的活化能Ea、指前因子A等动力学参数.结果表明:合成的聚醚型水性聚氨酯的热分解过程在氮气条件和氧气条件下均为二阶段过程,第一阶段为硬段链的分解,第二阶段为软段链的分解,同时氧气的存在促进了水性聚氨酯主链上C-C和C-O键的断裂.