水性聚氨酯的结晶动力学参数及其在鞋用胶黏剂的应用

Crystallization kinetics parameters of waterborne polyurethane and its application in adhesive for shoes

以聚己二酸1,4-丁二醇酯(PBA)、六亚甲基二异氰酸酯(HDI)和异佛尔酮二异氰酸酯(IPDI)为主要原料,制备了不同软段分子量和不同硬段含量的水性聚氨酯(WPU)乳液。采用DSC技术表征了WPU胶膜在非等温和等温条件下的结晶行为,并以莫志深方程和Avrami方程为模型,对WPU胶膜的结晶行为进行了研究。WPU胶膜的非等温结晶动力学分析结果表明,随着WPU相对结晶度的增加,非等温结晶动力学参数F(T)增大,说明适当提高活化温度可提高WPU胶黏剂的结晶速率和初黏强度;WPU胶膜的等温动力学分析结果表明,不同软段分子量和不同硬段含量的WPU胶膜的等温结晶动力学参数t1/2与相应WPU胶黏剂的开放时间存在对应关系,即t1/2较大者,相应WPU胶黏剂的开放时间较长。

Waterborne polyurethane （WPU） dispersions with different molecular weights of soft segment and different contents of hard segment were synthesized by using polyethylene glycol adipate diol （PBA）, isophorone diisocyanate （IPDI）, hexamethylene diisocyanate （HDI） as the main raw materials. The crystallization behavior of WPU films under isothermal and non-isothermal conditions were characterized by DSC, and their crystallization kinetics were investigated by Avrami equation and Mo Zhishen equation, respectively. The non-isothermal crystallization kinetics results showed that the non-isothermal crystallization kinetics parameters F（T） increased with the increase of relative crystallinity, which suggested that enhancement of activation temperature could improve the crystallization rate and initial bonding strength of WPU adhesive. The isothermal crystallization kinetics results indicated that a correspondence could be found between isothermal crystallization kinetics parameters hi2 of WPU films and the open time of WPU adhesive. The larger the tl/2 of WPU films was, the longer the open time of WPU adhesive would have.