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采用端羟丙基聚硅氧烷(DHPDMS)为改性剂,以异佛尔酮二异氰酸酯(IPDI)、聚丙二醇(PPG)、二羟甲基丙酸(DMPA)以及三羟甲基丙烷(TMP)为主要原料,通过预聚体法制备了聚氨酯多元醇水分散体系(SiHPUA),并与亲水改性多异氰酸酯固化剂配制成有机硅改性双组分水性聚氨酯(Si-2KWPU)。利用FTIR、1HNMR、XRD与TGA分别对聚合物结构与性能进行表征,研究了有机硅含量对多元醇水分散体和2KWPU涂膜性能的影响。结果表明,随着有机硅含量的增加,聚氨酯多元醇水分散体的粒径增大,黏度降低,涂膜的吸水率和拉伸强度下降,接触角和断裂伸长率升高。当体系中有机硅质量分数为5%时,涂膜的综合性能最佳,吸水率和接触角分别为6.2%、94.96°;热分解温度为272℃时,质量损失为5%。
Using terminal hydroxypropylpolysiloxane (DHPDMS) as modifier and isophorone diisocyanate (IPDI), polypropylene glycol (PPG), dimethylolpropionic acid (DMPA) and trimethylol propane TMP) as the main raw material, the polyurethane polyol dispersion system (SiHPUA) was prepared by the prepolymer method and the silicone-modified two-component aqueous polyurethane (Si-2KWPU) was prepared with hydrophilic modified polyisocyanate curing agent. The structure and properties of the polymers were characterized by FTIR, 1HNMR, XRD and TGA, respectively. The effects of silicone content on the properties of aqueous polyols and 2KWPU films were investigated. The results showed that with the increase of silicone content, the particle size of polyurethane polyol aqueous dispersion increased, the viscosity decreased, the water absorption and tensile strength decreased, and the contact angle and elongation at break increased. When the mass fraction of organic silicon in the system is 5%, the overall performance of the coating is the best, the water absorption and the contact angle are respectively 6.2% and 94.96 °, and the mass loss is 5% when the thermal decomposition temperature is 272 ℃.