表面接枝含氟树脂改性中空玻璃微珠/聚氨酯涂料的制备与性能研究

Preparation and Properties of Hollow Glass Beads Modified by Grafting Fluororesin and PU Coating

为改善中空玻璃微珠(HGB)与聚氨酯(PU)的相容性,同时赋予HGB其他功能,采用表面接枝法制备了表面接枝含氟树脂改性HGB(F-HGB),并以其为填料制备了聚氨酯涂料,进行隔热与阻燃性能研究。利用FTIR,SEM,EDS,接触角测定仪对所得改性HGB的成分、表面形貌、表面元素及表面润湿性进行测试分析;利用SEM对改性前后的HGB在涂层中的分散情况进行观察;利用导热系数仪、模拟曝晒装置研究玻璃微珠粒径、添加量、表面改性和涂层厚度对涂层隔热性能的影响;利用氧指数仪研究玻璃微珠粒径、添加量、改性对涂层阻燃性能的影响。结果表明:HGB表面成功接枝了含氟树脂;涂层隔热性能随玻璃微珠添加量增加而增强,同时F-HGB/PU涂料隔热效果优于HGB/PU涂料。当微珠添加量为20 phr(份数/100 g)时,F-K1/PU涂层导热系数为0.080 3W/(m·K),F-IM16K/PU涂层试板温差为5.5℃;F-HGB对涂层阻燃性能的提升效果优于HGB,当F-K1玻璃微珠添加量为20 phr(份数/100 g)时,F-K1/PU涂层极限氧指数(LOI)为25.5%。

In order to improve the compatibility of hollow glass beads( HGB) with polyurethane( PU) and to give HGB other functions,HGB surface-grafted with fluororesin( F-HGB) was prepared by surface grafting method,and then it was used as filler to prepare polyurethane coatings to study the thermal insulation and flame retardancy. The composition,surface morphology,surface elements and surface wettability of the modified HGB were tested and analyzed by FT-IR,SEM,EDS and contact angle tester. The dispersion of HGB before and after modification in coatings was observed by SEM. The effects of particle size,addition amount,surface modification and coating thickness on the thermal insulation properties of the coatings were studied by thermal conductivity meter and simulated exposure device. The influence of addition and modification of glass beads on the combustion performance of the coatings was studied by oxygen index meter. Results showed that the fluororesin was successfully grafted on the surface of HGB. The thermal insulation performance of the coating increased with the amount of glass beads,and the thermal insulation effect of F-HGB/PU coating was better than that of HGB/PU coating. When the HGB content was20 g/100 g,the thermal conductivity of the F-K1/PU coating was 0.080 3 W/( m·K),and the temperature difference of the F-IM16 K/PU coating test plate was 5.5 ℃ . The improvement effect of F-HGB on the flame retardancy of the coating was better than that of HGB. When the F-K1 content was 20 g/100 g,the limited oxygen index( LOI) of the coating was 25.5%.