硅胶按键用耐磨聚氨酯树脂的制备与表征

聚氨酯由硬段和软段交替组成,具有良好的物理和机械性能,在硅胶按键保护涂料方面的应用越来越广泛.随着对涂层耐磨性能要求的提高,开发一种针对于硅胶按键表面保护的高耐磨聚氨酯树脂变得十分关键.用聚酯二元醇(相对分子质量580)、乙二醇(EG)、三羟甲基丙烷(TMP)、异佛尔酮二异氰酸酯(IPDI)为原料合成了端羟基聚氨酯预聚物,使用封闭型异氰酸酯作为固化剂交联固化制备聚氨酯薄膜和涂层.研究了聚氨酯薄膜的拉伸性能、热性能以及聚氨酯涂层的耐磨性能,并探讨了EG和TMP用量对聚氨酯薄膜的热性能以及力学性能的影响,重点研究了二者对聚氨酯涂层耐磨性能的影响.测试结果表明:当聚氨酯树脂中EG和TMP的羟基摩尔分数分别为35％ ～ 39％和20％时,聚氨酯涂层的耐磨性能较佳,适用于制备硅胶表面保护涂料.

Preparation and Characterization of Wear Resistant Polyurethane for Protection of Silicone Keys

Polyurethane resins,composted of alternating hard and soft segments,have good physical and mechanical properties.It has been used as protective coating for silicone keys widely.With the increasing requirements of wear-resistance property of the coating,it becomes very critical to develop high wear-resistance polyurethane resin for surface protection of silicone keys.Telechelic polyurethane prepolymers with two hydroxyl ends were synthesized from polyester diols(Molecular weight 580),ethylene glycol(EG),trimethylolpropane(TMP),and isophorone diisocyanate(IPDI).Polyurethane film was prepared using blocked isocyanates as curing agent.The tensile and thermal properties of polyurethane films cured with blocked isocyanates curing agent,as well as the wear-resistance property of polyurethane coating were investigated.The results showed that when the amount of ethylene glycol and trimethylolpropane in polyurethane resins were 37-39% and 20%,respectively,the polyurethane coating exhibited an excellent wear-resistance.This coating could be used for protection of surface of the silicone keys.