汽车涂料用丙烯酸酯改性蓖麻油基水性聚氨酯无皂乳液研究

Study on preparation and performance of acrylate modified castor oil-based waterborne polyurethane soap-free emulsion for automotive coating

通过向丙烯酸单体（AC）中引入一定量含离子基的甲基丙烯酸（MAA）单体，采用种子乳液聚合法制得一系列丙烯酸酯改性的蓖麻油基水性聚氨酯无皂乳液（PuA）。通过傅里叶变换红外光谱（FTIR）、激光粒度仪、力学性能测试、耐水性试验和动态力学性能分析（DMA），详细研究了所制PUA乳液性能和PUA胶膜的力学性能、耐水性及动态力学性能。结果表明，当m（MAA）：m（AC）为1．5％时，乳液的平均粒径最小，粒径显示双峰分布、分布指数最高，乳液的稳定性最好，胶膜的拉伸强度最高、吸水率适中、玻璃化转变率最低．该乳液适用于汽车的底涂和表涂．

By introducing a certain amount of methacrylic acid （MAA） monomer containing ionic groups into the acrylic acid （AC） monomer and using emulsion polymerization method, a series of acrylate modified castor oil-based waterborne polyurethane soap-free emulsions （PUA） were prepared. The performance of the synthesized PUA emulsions and the mechanical performance, water resistance and dynamic mechanical performance of the PUA fihns were investigated in detail by using the FTIR, laser particle size analyzer, mechanical performance test, water resistance test and dynamic mechanical analysis （DMA）. The results show that when the m（MA）：m（AC） is 1.5%, the average particle size of the emulsion is the smallest, the particle size shows bimodal distribution, the distribution index is the highest, the stability of the emulsion is the best, the tensile strength of the film is the highest, the water absorption is moderate, the glass transition temperature is the lowest. As a result, the emulsion is suitable for the primer coating and surface coating of the automobile.