改性高岭土/水性聚氨酯复合材料的制备与表征

采用钛酸酯偶联剂干法改性高岭土,配成母液,用此母液乳化中和后的聚氨酯预聚体,制得改性高岭土/水性聚氨酯复合材料(WPUM)。研究了复合材料的乳液粒径、胶膜力学性能、结晶性和热稳定性等性能。结果表明:复合材料乳液粒径随着改性高岭土质量分数的增加,先增加后减小;改性高岭土的加入可以明显提高水性聚氨酯胶膜的力学性能,当改性高岭土质量分数为1.6%时,复合材料的断裂伸长率与纯聚氨酯胶膜相比提高了13%;X射线衍射法(XRD)分析结果显示,改性高岭土促进了聚氨酯的微相分离;热重分析法(TG)、差示热重法(DTG)分析结果表明,水性聚氨酯复合材料胶膜热分解的起始温度无变化,硬段最高热失重温度略有降低。

Preparation and characterization of modified kaolin/waterborne polyurethane composites

The kaolin was modified by dry method with titanate coupling agent, and the mother liquor was compounded with it. The modified kaolin/waterborne polyurethane composites （WPUM） were prepared by using said mother liquor for emulsifying neutralized polyurethane prepolymers. The performance including emulsion particle size, mechanical properties of the film, crystallinity and thermal stability of the composites was investigated. The results show that the particle size of composite emulsion first increases, then decreases with increase of kaolin mass fraction. Adding modified kaolin can significantly improve mechanical performance of waterborne polyurethane composite films. The elongation at break of the composites increases by 13% compared with that of pure polyurethane when the mass fraction of modified kaolin is 1.6%. The analysis results by X ray diffraction （XRD） method show that the modified kaolin promotes the micro-phase separation of polyurethane. The analysis results by thermogravimetry （TG） method and differential thermogravimetry （DTG） method show that the initial temperature for thermal decomposition of waterborne polyurethane composite films has no change, and the maximum thermogravimetric temperature of rigid segment slightly reduces.