硅丙乳液包覆Mg(OH)2核壳结构纳米粒子的制备与表征

为有效提高Mg(OH)_2纳米粒子在硅丙乳液中的相容性与分散稳定性,在油酸修饰Mg(OH)_2纳米粒子的基础上,以甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸与乙烯基三乙氧基硅烷为共聚单体,通过乳液聚合法制备出具有核壳结构的硅丙乳液包覆Mg(OH)_2复合材料。利用傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)、透射电子显微镜(TEM)等测试手段对样品结构、形貌进行了表征。通过燃烧实验,研究了硅丙乳液包覆Mg(OH)_2纳米粒子对水性防火涂料阻燃性能的影响。结果表明,油酸通过酯化作用修饰在Mg(OH)_2纳米粒子表面,借助油酸分子中双键结构,丙烯酸类混合单体在纳米Mg(OH)_2表面完成聚合过程,形成以Mg(OH)_2纳米粒子为核、硅丙乳液为壳的复合材料。XRD与热分析表明经硅丙乳液包覆的纳米Mg(OH)_2晶体结构与热稳定性能未受影响。此外,掺杂0.1%(质量分数)的硅丙乳液包覆Mg(OH)_2可使水性防火涂料阻燃时间延长至113 min,较未掺杂水性涂料阻燃时间(91min)提高约23%。

Preparation and Characterization of Silicone-acrylate/Magnesium Hydroxide Core-shell Structured Hybrid Nanoparticles

To effectively improve the compatibility and dispersion stability of magnesium hydroxide nanoparticles in the silicone-acrylate emulsion, core-shell silicone-acrylate/magnesium hydroxide (SA/MH) hybrid nanoparticles were prepared by means of grafting silicone-acrylate polymer, synthesis with butyl acrylate, methyl methacrylate, acrylic acid and vinyltriethoxysilane as co-monomers, onto the surface of nanoparticles after oleic acid modification. The obtained nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The effect of SA/MH composites on the flame retardancy in waterborne flame-retardant coating was also investigated by combustion test. The results showed that the silicone-acrylate polymer could be successfully grafted on the surface of oleic acid-modified MH and the uniformly-dispersed core-shell structure of SA/MH composites with MH-cores and SA-shell was formed. XRD and TGA indicated that the crystal structure and thermal stability of nanocomposites were not destroyed. Moreover, the coating containing 0.1% SA/MH nanocomposites showed the better fire protection performance with the longer-lasting protection time (113 min), 23% higher than that of undoped coating sample (91 min).