有机硅烷偶联剂改性紫外光固化超支化聚醚基水性聚氨酯的性能

采用超支化聚酯Boltorn H 20与丁二酸酐反应,制备了亲水性超支化聚酯,然后与甲基丙烯酸酯基改性的聚醚基聚氨酯预聚体和3-异氰酸酯基丙基三乙氧基硅烷(IPTS)反应,合成了有机硅烷偶联剂改性紫外光固化聚醚基超支化水性聚氨酯(WHPU)。考察了有机硅烷偶联剂用量对WHPU的耐酸性、固化时间、凝胶质量分数、附着力、水接触角、水吸附率、乳液粒径分布及热稳定性的影响。结果表明,当IPTS与Boltorn H 20中羟基的摩尔比为6/16时,固化后的WHPU膜的凝胶质量分数为92%,在玻璃表面的附着力达到0级;与不含有机硅烷偶联剂的WHPU相比,该涂膜的水接触角和热稳定性分别提高了34°和22℃,其吸水率从13.8%降低到4.3%。

Properties of ultraviolet cured hyperbranched polyether-based waterborne polyurethane modified by organosilane coupling agent

Hydrophilic hyperbranched polyester was prepared by the reaction of hyperbranched Boltorn H 20 polyester with succinic anhydride. And then ultraviolet cured hyperbranched polyether-based waterborne polyurethane modified by organosilane coupling agent(WHPU) was synthesized by sequential reaction of the hydrophilic hyperbranched polyester with methacrylate-modified polyether-based polyurethane prepolymer and 3-isocyanatepropyltriethoxysilane(IPTS). The effects of organosilane coupling agent amount on the acid resistance, curing time, gel mass fraction, adhesion, water contact angle, water adsorption rate, distribution of particle size of emulsion, latex morphology and thermal stability of WHPU were explored. The results showed that when the molar ratio of IPTS to hydroxyl groups in the hyperbranched polyester Boltorn H 20 was 6/16, the gel mass fraction of the cured WHPU film was 92%, and the adhesion on the glass surface reached 0 level. Compared with WHPU without organosilane coupling agent, the water contact angle and thermal stability of the coating film were increased by 34° and 22 ℃, and its water absorption decreased from 13.8% to 4.3%.