成核剂对共聚酯热熔胶结晶动力学的影响

A copolyester hot melt adhesive was prepared by transesterification, esterificcation and polycondensation from dimethylterephthalate(DMT), dicarboxylic acid and dihydric alcohol. The influences of nucleating agents and crystallizing promoter on its crystallization kinetics was studied by measurement of depolarized light intensity with time. It was found that the complex additives composed of inorganic nucleating agent, organic agents and crystallization promoter could significantly accelerate the crystallization process of the copolyester due to the reduction of the activation energies of crystal nucleation and crystal growth.

成核剂在PET结晶中的应用

介绍了聚合物的结晶理论,在PET中加入成核剂进行共混,可以提高PET的结晶速度。阐述了国内外采用成核剂提高PET结晶速度的研究情况,并指出了适用于PET热熔胶的成核剂种类。

结晶成核剂对水性聚氨酯热熔黏合剂性能的影响

以聚己二酸1,4-丁二醇酯(PBA)、甲苯二异氰酸酯(TDI)、甲醇和甲乙酮肟(MEKO)为主要原料,制备了不同结构的结晶成核剂,并对水性聚氨酯乳液(WPU)进行改性,得到结晶速度提升的水性聚氨酯热熔黏合剂乳液。通过黏合剂成膜的DSC热循环测试,综合分析了结晶成核剂对水性聚氨酯热熔黏合剂结晶速率、结晶度的影响。研究结果表明:非反应型的结晶成核剂对结晶行为的影响是可循环的,反应型的结晶成核剂在解封闭前后影响不同;结合黏合剂施胶-贴合-剥离测试的结果分析可知,结晶速度是影响剥离强度随时间爬升速率的主要影响因素,但最终剥离强度与胶膜最终的本体强度相关;反应型结晶成核剂用量为15%时,对聚氨酯热熔黏合剂的综合性能提升较佳。