KH560改性纳米硅溶胶对苯丙涂层性能的影响

目的提高硅溶胶-苯丙复合涂层的综合性能,为有机-无机复合涂层的应用提供一定的参考意义。方法采用水浴加热机械搅拌/超声分散法,用KH560对硅溶胶进行表面改性,并将改性前后的硅溶胶与苯丙乳液共混,制备了含改性前后硅溶胶15%、30%、45%(质量分数,全文同)的硅溶胶-苯丙复合涂层。用红外光谱仪证实改性成功。用紫外/可见/近红外分光光度计、力学性能测试仪、扫描电子显微镜对改性前后硅溶胶-苯丙复合涂层综合性能及微观结构进行表征。结果含有改性后硅溶胶的复合涂层综合性能得到明显提高,当改性硅溶胶掺量为30%时,复合涂层综合性能最好,此时复合涂层磨耗值为0.078 g,附着力为1级,抗冲击性为62 mm,拉伸强度为4.74 MPa,断裂伸长率为215.90%,附着力、抗冲击性、拉伸强度和断裂伸长率分别比相同掺量下未改性硅溶胶复合涂层提高1级、6 mm、0.59 MPa和10.34%。结论 KH560可成功地对硅溶胶进行表面改性,将改性后的硅溶胶替代未改性的硅溶胶可提高硅溶胶-苯丙复合涂层的综合性能,实际应用时改性硅溶胶掺量以30%为宜。

Effects of Nano Silica Sol Modified by KH650 on Properties of Styrene Acrylic Coating

The work aims to improve overall performance of silica sol-styrene acrylate composite coating and provide reference for application of organic-inorganic composite coating. Silica sol was modified with KH560 in the method of water-bath heating and mechanical stirring/ultrasonic dispersing. Samples containing 15%, 30% and 45% (mass fraction, applicable to the whole context) unmodified/modified nano silica sol-styrene acrylate composite coating were prepared by mixing unmodified/modified nano silica sol with styrene acrylate emulsion. Modification was verified to be successful by infrared spectrometer. Overall performance and microstructure of unmodified/modified silica sol-styrene acrylate composite coating were characterized with ultraviolet/visible/near-infrared spectrophotometer, mechanical property tester and scanning electron microscope. Overall performance of composite coating containing modified silica sol was significantly improved. The composite coating exhibited the best overall performance when content of modified nano silica sol was 30%. Wear loss, adhesive force, impact resistance, strength and elongation at break of the coating was 0.078 g, grade 1, 62 mm, 4.74 MPa and 205.56%, respectively, its adhesive force, impact resistance, strength and elongation at break was 1 level, 6 mm, 0.59 MPa and 10.34% higher than that of unmodified coating. Nano silica sol can be successfully modified by KH560. Overall performance of the silica sol-styrene acrylate composite coating can be improved by using modified silica sol instead of unmodified. Proper content of modified silica sol is 30% during practical application.