Abstract The phase behaviors involving the phase fluctuation in melt of poly(vinylidene fluoride) (PVDF)/poly(methyl methacrylate) (PMMA) blends with varying graphite oxide concentration were investigated through dynamic rheological measurement. The phase diagrams of the blends with different concentration of graphite oxide were achieved through dynamic temperature and frequency sweep, showing the incorporation of graphite oxide would shift up the phase diagram of PVDF/PMMA blends and enlarge the miscibility window of the blends. Dynamic time sweep was applied to track the phase separation process, which exhibited that graphite oxide can slow down the phase separation process. The underlying mechanism for graphite oxide-driven miscibility in PVDF/PMMA blends was explored via evaluating the molecular entanglement of PVDF/PMMA/Graphite Oxide ternary composites. The interfacial tensions showed the selective adsorption of PMMA on graphite oxide, which was responsible for the role of graphite oxide as entanglement points. And it was found the increase of graphite oxide concentration could lead to higher entanglement density. Therefore, it can be concluded that the graphite oxide can act as entanglement point, further to stabilize the phase structure and to slow down the phase separation. This work serves as an experimental verification to enrich the thermodynamic and kinetic investigations on phase behaviors of particle-filled miscible blends; furthermore new insights are produced and provided to tailor the phase morphology of miscible blends via incorporation of particles.

中文翻译：

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PVDF/PMMA 混合物中氧化石墨驱动的混溶性：通过动态流变学方法评估

摘要 通过动态流变测量研究了聚偏二氟乙烯 (PVDF)/聚甲基丙烯酸甲酯 (PMMA) 共混物与不同氧化石墨浓度的熔体相波动的相行为。通过动态温度和频率扫描获得了不同氧化石墨浓度共混物的相图，表明氧化石墨的掺入会使 PVDF/PMMA 共混物的相图上移并扩大共混物的混溶窗口。应用动态时间扫描来跟踪相分离过程，这表明氧化石墨可以减慢相分离过程。通过评估 PVDF/PMMA/氧化石墨三元复合材料的分子缠结，探索了 PVDF/PMMA 共混物中氧化石墨驱动的混溶性的潜在机制。界面张力表明 PMMA 选择性吸附在氧化石墨上，这是氧化石墨作为缠结点的原因。并且发现氧化石墨浓度的增加会导致更高的缠结密度。因此，可以得出结论，氧化石墨可以作为缠结点，进一步稳定相结构并减缓相分离。这项工作作为实验验证，丰富了对颗粒填充的混相混合物相行为的热力学和动力学研究；