有机锡对聚氨酯脲弹性体固化过程的形态及力学性能的影响

Effect of Organic Tin on the Morpholoyg and Mechanical Properties During Polyurethane-urea Curing Process

采用“原位”傅里叶变换红外技术 ,研究了半预聚物法聚氨酯脲 (PUU)本体聚合反应过程中的形态变化。通过对羰基区振动谱带变化的定量研究。详细讨论了催化剂二月桂酸二丁基锡在聚合反应过程中 ,对聚氨酯酯脲形态结构及力学性能的影响。结果表明 :随着有机锡浓度的增大 ,硬段区氢键化脲键的有序性降低 ,当 NCO/ OH反应的速率常数和 NCO/ NH2 反应的速率常数相近时 ,材料的力学性能较好。

The mechanical properties and morphology of crosslined PUU in bulk quasi-prepolymer process was studied by in situ FTIR.From th e quantitative change of carbonyl FTIR spectra,the development of morphology bet ween noncatalyzed and catalyzed polymerization process was discussed in detail.T he effect of organic tin concentration on the mechanical propreties was investi gated.It showed that urea carbonyl splited many small weak bands at different si tes with increasing of organic tin concentration,and the catalyst played an impo rtant role in controling the morphology and mechanical properties.It also showed that the mechanical properties reached extreme value when the rate constant of -NCO/-OH reaction equate the rate constant of -NCO/-OH reaction.