This article reports ultrasound–assisted synthesis of polymethyl methacrylate (PMMA)/reduced graphene oxide (RGO) nanocomposites by in situ emulsion polymerization coupled with in situ reduction of graphene oxide. The thermal degradation kinetics of the nanocomposites was also assessed with Criado and Coats-Redfern methods. Intense microconvection generated by ultrasound and cavitation results in uniform dispersion of RGO in the polymer matrix, which imparts markedly higher physical properties to resulting nanocomposites at low (≤1.0 wt %) RGO loadings, as compared to nanocomposites synthesized with mechanical stirring. Some important properties of the PMMA/RGO nanocomposites synthesized with sonication (with various RGO loadings) are: glass transition temperature (0.4 wt %) = 124.5°C, tensile strength (0.4 wt %) = 40.4 MPa, electrical conductivity (1.0 wt %) = 2 × 10⁻⁷ S/cm, electromagnetic interference shielding effectiveness (1.0 wt %) = 3.3 dB. Predominant thermal degradation mechanism of nanocomposites (1.0 wt % RGO) is 1D diffusion with activation energy of 111.3 kJ/mol. © 2017 American Institute of Chemical Engineers AIChE J, 2017

中文翻译：

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超声辅助合成和甲基丙烯酸甲酯/还原氧化石墨烯纳米复合材料的表征

本文报道了原位乳液聚合与原位氧化石墨烯还原相结合的超声辅助合成聚甲基丙烯酸甲酯（PMMA）/氧化石墨烯（RGO）纳米复合材料的方法。纳米复合材料的热降解动力学也用Criado和Coats-Redfern方法进行了评估。与通过机械搅拌合成的纳米复合材料相比，超声和空化产生的强烈微对流导致RGO在聚合物基质中均匀分散，从而在低（≤1.0wt％）RGO负载下为所得纳米复合材料赋予了显着更高的物理性能。通过超声处理（具有各种RGO负载）合成的PMMA / RGO纳米复合材料的一些重要特性是：玻璃化转变温度（0.4 wt％）= 124.5°C，拉伸强度（0.4 wt％）= 40.4 MPa，^-7 S / cm，电磁干扰屏蔽效果（1.0 wt％）= 3.3 dB。纳米复合材料（1.0 wt％RGO）的主要热降解机理是一维扩散，其活化能为111.3 kJ / mol。©2017美国化学工程师学会AIChE J，2017