PMMA/TiO2纳米复合粒子的制备及初步应用研究

采用原位乳液聚合法，用经硅烷偶联剂处理过的纳米TiO₂，与MMA单体混合，合成PMMA/TiO₂纳米复合粒子。探讨了TiO₂表面改性机理， 并用TG、IR、DSC等对产物进行了表征，表明纳米TiO₂被包覆在聚合物PMMA中。将复合粒子加入紫外光固化涂料，制得复合涂膜。由原子力显微镜照片分析，制备的PMMA/ TiO₂复合粒子平均粒径约为75nm。分别在涂膜中添加等量的纳米TiO₂和PMMA/ TiO₂纳米复合粒子，制成两张复合涂膜，比较发现PMMA/ TiO₂纳米复合粒子在涂膜中的分散情况优于纳米TiO₂，呈现良好的纳米级分散，明显改善了TiO₂与涂膜的相容性，从而提高了涂膜的硬度及涂膜与基材的附着力。

Preparation and preliminary study of applications of poly (methylmethacrylate)/titania nano-composite particles

Poly(methyl methacrylate)/titania(PMMA/ TiO₂) nano-composite particles have been synthesized by in-situ emulsion polymerization of MMA using nano- TiO₂treated with KH-570. The mechanism of modification was studied. The surfaces of nano- TiO₂ particles were changed from hydrophilic to hydrophobic, and active organic functional groups were grafted onto the surfaces of the particles. Thermogravimetry (TG), infrared (IR) spectroscopy and differential scanning calorimetry (DSC) were used to characterize the nano-composite particles. The results showed that nano-TiO₂ was coated with PMMA. The nano-composite particles were mixed with a UV-curable coating in order to prepare a composite coating film. An atomic force microscopy (AFM) image of the film revealed a fine dispersion with an average particle size of 75nm. PMMA/ TiO₂ has better compatibility with the UV-curable coating components than pure nano- TiO₂. As a result, both the hardness of the film and the adhesion with the substrate are enhanced.