Poly(methyl methacrylate) (PMMA)/clay nanocomposites (NCs) were prepared by suspension polymerization of methyl methacrylate in the presence of two different organoclays (Cloisite 30B, Cloisite 15A) with clay loading ranged from 0.5 to 5 wt%. Increase in molecular weight of the PMMA matrix with addition of the clay was revealed by gel permeation chromatography (GPC) and intrinsic viscosity measurements. As confirmed by X-ray diffraction (XRD), the NCs had an intercalated structure. The organoclays-MMA/PMMA compatibility was investigated by swelling tests and solubility parameter approach. Rheological behavior of PMMA NCs in molten state was analyzed through construction of master curves of complex viscosity, storage, and loss modulus by applying the time–temperature superposition procedure. Melt rheology, scanning electron microscopy (SEM), and UV/Vis spectroscopy results confirmed higher extent of clay dispersion in the NCs with Cloisite 30B. Compared to pure PMMA, all these NCs show increase of glass transition temperature as measured by DSC and improved thermal stability determined by thermogravimetric analysis (TGA). The results obtained by dynamic mechanical analysis showed that the storage modulus of the NCs was higher by incorporation of clay into the PMMA matrix, increasing as the amount of clay increased and that their mechanical performance was significantly enhanced.

中文翻译：

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有机粘土改性剂结构对聚甲基丙烯酸甲酯/有机粘土纳米复合材料粘弹性和热性能的影响

聚（甲基丙烯酸甲酯）（PMMA）/粘土纳米复合材料（NCs）是在两种不同的有机粘土（Cloisite 30B、Cloisite 15A）存在下通过甲基丙烯酸甲酯的悬浮聚合制备的，粘土负载范围为 0.5 至 5 wt%。通过凝胶渗透色谱 (GPC) 和特性粘度测量揭示了添加粘土后 PMMA 基质的分子量增加。X射线衍射（XRD）证实，NCs具有插层结构。通过溶胀试验和溶解度参数方法研究了有机粘土-MMA/PMMA的相容性。通过应用时间-温度叠加程序构建复粘度、储存和损耗模量的主曲线，分析了熔融状态下 PMMA NCs 的流变行为。熔体流变学，扫描电子显微镜 (SEM)，UV/Vis 光谱结果证实了使用 Cloisite 30B 的 NC 中粘土分散程度更高。与纯 PMMA 相比，所有这些 NC 都显示出由 DSC 测量的玻璃化转变温度的增加和由热重分析 (TGA) 确定的热稳定性的提高。通过动态力学分析获得的结果表明，通过将粘土掺入 PMMA 基体中，NCs 的储能模量更高，随着粘土量的增加而增加，并且其机械性能显着增强。