埃洛石纳米管/水性环氧树脂复合材料的性能

Properties of Halloysite Nanotubes/Waterborne Epoxy Resin Composites

采用超声分散与机械搅拌混合方法制备了埃洛石纳米管(HNTs)/水性环氧树脂复合材料。通过TEM、SEM对HNTs及复合材料进行了表征,并分析了HNTs含量对水性环氧树脂乳液的流变行为、乳胶膜的热稳定性及涂膜性能的影响。结果表明:HNTs可在水性环氧树脂体系中均匀分散,使复合材料由脆性断裂转变为韧性断裂;但当w(HNTs)>5%时,复合材料出现明显团聚,最佳添加量为w(HNTs)=2%,此时复合体系的热稳定性增强,热分解温度由358℃提高到365℃,剪切速率为10 s-1时,黏度由0.73 Pa·s增加到0.85 Pa·s;HNTs起到类交联点的作用;储能模量提高了8.1倍,内耗降低,复合体系呈现假塑性和明显的触变性,稳定性增强,水性环氧树脂乳胶膜的耐水性得到改善,与未添加HNTs的环氧树脂相比,当w(HNTs)=5%时,吸水率由27.8%降低到15.9%,涂膜的硬度由3H提高到4H,柔韧性由1 mm提高到0.5 mm。但当w(HNTs)>5%时,体系结构与稳定性会被破坏,导致涂膜综合性能下降。

Halloysite nanotubes（HNTs）/waterborne epoxy resin composite material was prepared through ultrasonic dispersion and mechanical blending. The morphology of HNTs and composites were characterized by TEM and SEM. Effects of HNTs content on the rheology,thermal stability and film performance of waterborne epoxy system were systematically investigated. It was found that HNTs were able to uniformly disperse in composites. The fracture characteristic of film transferred from brittle fracture to ductile fracture. However,aggregation took place when the HNTs content was more than 5%.The results showed that the optimum content was 2%. The thermal stability of composites was enhanced,and the thermal decomposition temperature increased from 358 ℃ to 365 ℃. When the shear rate was 10s-1,the viscosity increased from 0. 73 Pa·s to 0. 85 Pa·s. The storage modulus increased by 8. 1 times of magnitude,and the loss factor decreased,the composite system presented pseudoplasticity and obvious thixotropy,and the composite stability was improved. It suggested that the HNTs can be functionalized as crosslinking points in composites. In addition,the water resistance of composite was enhanced,the water absorption decreased from 27. 8% to 15. 9%. The hardness increased from 3H to 4H,and flexibility of film increased from 1 mm to 0. 5 mm. However,when the HNTs content was more than 5%,excessive HNTs would destroy the crosslinking structure and be unfavorable to the stability and comprehensive properties of composite films.