纳米水合氧化铝的表面处理

SURFACE MODIFICATION OF NANOSIZED ALUMINA HYDRATE

采用表面接枝聚合法对纳米水合氧化铝进行了表面处理 ,以改善纳米水合氧化铝在有机溶剂和聚合物基体中的分散性。实验先将相同质量的硅烷偶联剂KH5 70与纳米水合氧化铝在无水乙醇中沸点回流搅拌 4h ,使KH5 70与水合氧化铝表面羟基进行反应并接枝到其表面 ;再将经过处理后的粉体以 1∶2 (质量比 )的比例与甲基丙烯酸甲酯在水 /乙醇 (体积比 1∶1 )溶液中 6 5℃下聚合 6h形成表面接枝PMMA的纳米复合粉体。分别用FT/IR4 6 0Plus红外分光光度仪、TGA/SDTA 81 5e热重分析仪、JSM - 5 6 0 0LV扫描电镜、Oxford能谱仪、JEM - 2 0 0EX透射电镜进行表征。实验结果表明 ,PMMA已经成功接枝到纳米水合氧化铝表面 ,表面处理后的水合氧化铝由亲水性变为亲油性 。

To enhance the dispersity of nanosized alumina hydrate (Al_2O_3·xH_2O)in organic solvent and polymer matrix,an effective surface modification method was developed by grafting PMMA onto the Al_2O_3·xH_2O nanoparticles. The Al_2O_3·xH_2O and the silane coupling agent KH570 (mass ratio is 1∶1) were firstly violently stirted in ethanol at boiling point for 4 h, then the silane treated nanopowder and the methacrylate (MMA) (mass ratio is 1∶2) copolymerized at 65 ℃ for 6 h in the water/ethanol (volume ratio is 1∶1)system. The product and its dispersion properties were investigated by FT/IR, DTA, SEM and TEM etc. Results show that PMMA is engrafted on the surface of nanosized Al_2O_3·xH_2O and thus greatly change its surface characteristics from hydrophilia to lipophilicity. Great dispersity and stability can be obtained for this product in toluene.