硅烷偶联剂原位包覆纳米TiO_2及其在PVC功能改性中的应用

Application in functional modification of PVC by silane coupling agent modificated nanometer TiO_2

通过原位聚合法在金红石型纳米TiO2表面包覆硅烷偶联剂,研究超声波处理时间、水浴时间及溶液的pH值对改性效果的影响。结果表明:当超声时间为60min、水浴时间为2h、溶液的pH=6时,其改性效果最佳;采用扫描电镜、X射线衍射、差示扫描量热分析法、紫外-可见分光光度计、氧指数测试仪等手段对试样进行表征,结果显示:纳米TiO2与偶联剂之间的结合为化学结合,改性后的纳米粒子分散性得到了提高,当纳米TiO2添加量为3%时,PVC/KH570-TiO2复合材料的阻燃性能与机械性能最佳。

The silane coupling agent was grafted on the surface of rutile TiO2 by in situ polymerization. Ultrasound,bain-marie and the different kinds of p H were studied to evaluate the modified results. It was found that the optimum surface modification conditions were determined： the ultrasound was 60 min,bain-marie was 2h and p H = 6. The samples before and after modification were characterized by SEM,XRD,DSC,UV-Vis and so on. The results showed that coupling agent combines nanoparticles by chemical action. The reunion of nanoparticles was decreased after modification. Therefore the dispersion of particles was enhanced. Mechanical properties and oxygen index of PVC / KH570-TiO2 were effectively improved at the content of modified TiO2（ 3% wt）.