亲水SiO2改性水性聚氨酯-聚丙烯酸酯的制备及性能

Synthesis and performance of WPUA modified with WSiO2 by solvent-free method

为了提高水性聚氨酯材料的耐热性、耐化学试剂性及力学性能,利用甲基丙烯酸甲酯(MMA)作为聚氨酯预聚合的连续相,同时采用羧酸型以及磺酸型亲水扩链剂,乳化时引入反应性的亲水性纳米二氧化硅(WSiO2),通过无有机溶剂法制备了稳定的耐温水性聚氨酯-聚丙烯酸酯(WPUA)乳液。利用透射电镜、红外光谱、X射线衍射和热重等手段研究了WPUA乳液及其膜的结构和性质。结果表明:随着样品中WSiO2含量的增加,WPUA乳液的平均粒径增大,WPUA膜的光泽度下降,硬度、附着力增加,WPUA薄膜的硬度和附着力增加,拉伸强度值先上升后下降,最佳WSiO2添加量为1%。适量的WSiO2可以改善WPUA材料的耐热行为。当热分解率为50%时,WSiO2改性后WPUA的分解温度比改性前提高了39℃。WSiO2改性使WPUA的力学和耐化学试剂性也得到了改善。

In order to improve the heat resistance,chemical reagent resistance and mechanical properties of waterborne polyurethane materials,the stable waterborne polyurethane-polyacrylate(WPUA)emulsion was prepared with methyl methacrylate(MMA)as dispersion medium by solvent-free method.Both carboxylic type and sulfonate hydrophilic chain extender were used and hydrophilic nano-silica(WSiO2)was introduced during the emulsification of polyurethane.The structure and properties of WPUA emulsions and films were characterized by TEM,FT-IR,XRD and TG.The results showed that the average particle size of WPUA emulsions increased with the increasing WSiO2 content,while the gloss of the WPUA films decreased,the hardness and adhesion increased,the tensile strength increased first and then decreased.The best addition quantity of WSiO2 was 1%.WSiO2 can improve the heat resistance of WPUA materials.compared with the WPUA without modification,the decomposition temperature of WPUA with modification by WSiO2 increased by 39℃ when the thermal decomposition rate was 50%.WSiO2 can also improve the chemical reagent resistance and mechanical properties of WPUA films.