有机硅改性水性聚氨酯乳液的研制

Preparation of Silicone Modified Waterborne Polyurethane Emulsion

以二氧化碳基二元醇(PPC)、聚丙二醇、聚酯二醇、甲苯二异氰酸酯、二羟甲基丙酸、N-2-氨乙基-3-氨丙基三甲氧基硅烷(KH 792)、三乙胺为主要原料,制得有机硅改性聚氨酯(Si-WPU)乳液。研究了异氰酸酯基与羟基物质的量之比(R值)、软段种类与含量、KH 792用量对Si-WPU外观、粒径、稳定性的影响,并研究了其对Si-WPU固化后胶膜的力学强度、附着力、吸水率、水接触角和耐热性能的影响。结果表明,当R值为1.67、PPC为软段且含量为75%、KH 792用量为3.5%时,制得的Si-WPU乳液外观为泛蓝乳液状且稳定性较佳,黏度为313 mPa·s,粒径为213 nm;该条件下Si-WPU固化膜的综合性能较佳,硬度为2H、拉伸强度为53.83 MPa、断裂伸长率为1465%、附着力等级为4B、水接触角为93.5°、吸水率为2.65%。可为高性能环保水性聚氨酯涂层提供一条新的制备路径。

A silicone-modified waterborne polyurethane emulsion(Si-WPU)was prepared by carbon dioxide binary alcohol(PPC),polypropylene glycol,poly-1,4-butylene adipate glycol,4-methyl-m-phenylene diisocyanate,2,2-bis(hydroxymethyl)propionic acid,N-[3-(trimethoxysilyl)propyl]ethylenediamine(KH 792)and triethylamine as the main raw materials.The influence of R(the mole ratio of isocyanate to hydroxyl group),the type and content of soft chain segment as well as the amount of KH 792 on the appearance,particle size and stability of Si-WPU emulsion were studied.The influence of mechanical strength,adhesion,water absorption,water contact angle and heat resistance of the cured Si-WPU film was also systematically studied.The results showed that when R was 1.67,PPC was the soft-chain segment with an addition volume of 75wt%,and KH 792 was 3.5wt%,Si-WPU emulsion was pan-blue with low viscosity,low particle size and good stability,i.e.,the viscosity was 313 mPa·s and particle size was 213 nm.In addition,the Si-WPU film showed better comprehensive performance,with hardness of 2 H,tensile strength of 53.83 MPa,fracture elongation of 1465%,adhesion grade of 4B,water contact angle of 93.5°and water absorption rate of 2.65%.A novel preparation route has been provided for high-performance and environmentally friendly waterborne polyurethane coating.