有机化蒙脱土对聚氨酯防水涂料力学和老化性能的影响

Effect of organic modified montmorillonite on mechanical and aging properties of polyurethane waterproof coatings

关键词:  防水涂料  聚氨酯  蒙脱土  力学性能  老化性能

Key words:  waterproof coatings  polyurethane  montmorillonite  mechanical properties  aging performance

摘要:

采用γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)和十八烷基二甲基苄基氯化铵(ODBA)分别对蒙脱土(MMT)进行了有机化改性,制备了KH560表面修饰蒙脱土(KH560/MMT)和ODBA有机插层蒙脱土(ODBA/MMT),研究了不同蒙脱土对聚氨酯防水涂料力学和老化性能的影响。结果表明,MMT、KH560/MMT和ODBA/MMT均可提高聚氨酯防水涂料的力学性能和抗老化性能,但KH560/MMT和ODBA/MMT的改善效果明显优于MMT。与聚氨酯防水涂料相比,掺加5 wt.%KH560/MMT的聚氨酯防水涂料的拉伸强度、断裂伸长率、撕裂强度和粘结强度分别提高了30.50%、9.87%、11.32%和16.55%,掺加5 wt.%ODBA/MMT的聚氨酯防水涂料则相应提高了40.00%、11.68%、16.40%和21.38%。经25 d老化后,聚氨酯防水涂料热老化和紫外老化后的拉伸强度保持率(RT)和断裂伸长率保持率(RE)分别为67.50%、69.95%和66.50%、65.11%,而掺加5 wt.%KH560/MMT的聚氨酯防水涂料老化后的RT和RE保持率分别为79.31%、80.23%和78.16%、78.30%,掺加5 wt.%ODBA/MMT的聚氨酯防水涂料老化后的RT和RE保持率分别为83.57%、82.24%和81.43%、81.44%。相比KH560/MMT,ODBA/MMT对聚氨酯防水涂料的力学和老化性能具有更好的改善效果。

Abstract:

Montmorillonite (MMT) was organically modified by γ-glycidyl ether oxypropyl trimethoxy-silane (KH560) and octadecyl dimethyl benzyl ammonium chloride (ODBA), respectively, KH560 surface-modified montmorillonite (KH560/MMT) and ODBA organically intercalated montmorillonite (ODBA/MMT) were prepared. The effects of different montmorillonites on the mechanical and aging properties of polyurethane waterproof coatings were investigated. The results showed that MMT, KH560/MMT and ODBA/MMT improve the mechanical properties and anti-aging properties of polyurethane waterproof coatings, however, KH560/MMT and ODBA/MMT demonstrate significantly superior improvements compared to MMT.Specifically, for polyurethane waterproof coatings incorporating 5 wt.% KH560/MMT, the tensile strength, elongation at break, tear strength, and adhesion strength increased by 30.50%, 9.87%, 11.32%, and 16.55%, respectively. In contrast,the addition of 5 wt.% ODBA/MMT showed corresponding improvement of 40.00%, 11.68%, 16.40%, and 21.38%. After 25 days of thermal and ultraviolet aging, the tensile strength retention rate (RT) and elongation at break rate (RE) of polyurethane waterproof coatings were 67.50%, 69.95% and 66.50%, 65.11%, respectively. In comparison, the retention of RT and RE of polyurethane waterproof coatings with 5 wt.% KH560/MMT were 79.31%, 80.23% and 78.16%, 78.30%, respectively, while those with 5 wt.% ODBA/MMT showed RT and RE retention rates of 83.57%,82.24% and 81.43%, 81.44%, respectively. Overall, compared with KH560/MMT, ODBA/MMT provides a better improvement effect on the mechanical and aging properties of polyurethane waterproof coatings.