皮革用双组份WPU胶黏剂的制备及性能

Preparation and Properties of Two-component WPU Adhesives for Leather

摘要:

以异佛尔酮二异氰酸酯、聚己内酯二元醇为主要原料，二羟甲基丁酸为亲水性单体，三乙胺、1,4-丁二醇、三羟甲基丙烷和有机硅交联剂分别为中和剂、小分子扩链剂、内交联剂和外交联剂，采用丙酮法首先合成不同R值（-NCO/-OH）的端羟基水性聚氨酯（WPU）乳液。然后加入2%的封闭型水性异氰酸酯类固化剂，制备出性能优异的双组份端羟基WPU胶黏剂。采用红外光谱仪、核磁共振光谱仪、激光粒度分析仪、透射电镜、流变仪对胶黏剂的化学结构，形貌及流变性能进行了表征；通过热失重分析仪、多功能材料实验机研究了胶膜的热力学性能和机械性能。结果表明，当R值为0.85时，所制备的胶黏剂综合性能最佳，胶膜吸水率为19%，拉伸强度为14.74Mpa，断裂伸长率为236.53%，剥离强度为0.421KN/m。 关键词：双组份；水性聚氨酯；胶黏剂；剥离强度。

Abstract:

Hydroxyl-terminated waterborne polyurethane (WPU) emulsions with different R values(-NCO/-OH) were synthesized firstly via acetone method, in which isophorone diisocyanate and poly (ε-caprolactone) di-OH are the main raw materials, with dihydroxy methyl butyric acid as hydrophilic monomer, triethylamine, 1, 4-butanediol, trimethylolpropane and organic silicon crosslinker as neutralizing agent, small molecule chain extender, inner-crosslinking agent and outer-crosslinking agent respectively. Then, two-component hydroxyl-terminated WPU adhesives with excellent properties were prepared by adding the 2% enclosed water-based isocyanate curing agents. The chemical structure, morphology and rheological properties of the adhesives were characterized by infrared spectroscopy, nuclear magnetic resonance, laser particle size analyzer, transmission electron microscopy and rheometer, seperately. Furthermore, the thermal and mechanical properties of the film were characterized via thermo-gravimetric analyzer and universal tensile testing machine. The results showed that comprehensive properties of adhesive prepared were best when R value is 0.85, the water absorption, tensile strength, elongation at break and peel strength of film is 19%, 14.74 Mpa, 236.53% and 0.421 KN/m, respectively.