单组分聚氨酯/蒙脱土纳米复合防水涂料的研究

采用插层聚合法制备单组分聚氨酯/蒙脱土(PU/OMMT)纳米复合防水涂料,并研究蒙脱土用量对涂料的结构与性能的影响。广角X—射线(WAXD)衍射分析表明,聚氨酯在蒙脱土片层间进行插层聚合,可导致蒙脱土层间距扩大。与PU相比,在有机蒙脱土(OMMT)用量为3%以内时,PU/OMMT纳米复合防水涂料的拉伸强度、断裂伸长率均明显提高,而在OMMT用量为3%以上时,由于OMMT片层间含有有机铵,其活泼氢可与—NCO反应,导致PU/OMMT复合防水涂料的—NCO含量下降,固化交联度不够,致使其力学性能下降。

Single-component PU/OMMT waterproof nano-coating were prepared by intercalation polymerization and the influence of OMMT amount on structure and property of nano-coatings were studied.By WAXD analysis,the galleries distance of OMMT is increased by intercalation and polymerization of PU.The result indicates that PU/OMMT nano-coating is obviously better than PU on tensile strength and extensibility at break when the content of OMMT is less than3%.However,the content of-NCO in PU/OMMT waterproof nano-coating decreases remarkably when the content of OMMT is over3%,because of reaction of reactive hydrogen of OMMT with-NCO,which make the degree of crosslink insufficient and mechanical properties of PU/OMMT lower down.