Abstract The location and migration of poly (methyl methacrylate)-grafted clay (clay-g-PMMA) nanosheets with low grafting density in a phase-separated polymer blend of poly (methyl methacrylate)/poly (styrene-co-acrylonitrile) (PMMA/SAN) was investigated. The grafting density and molecular weight for grafted PMMA chains on the surface of clay nanosheets was about 0.04 chains/nm2 and 7.8 × 104, respectively, indicating that the grafted chains might exhibit the mushroom-like distribution. With phase separation of PMMA/SAN blend matrix, the well-dispersed clay-g-PMMA nanosheets in the blend matrix were first located in the SAN-rich phase and then gradually migrated to the interface between PMMA and SAN. The first abnormal location of modified clay in the blend matrix might be attributed to the favorable interaction between clay-g-PMMA and SAN induced by the miscibility of grafted PMMA/surrounding SAN chains and the unfavorable interaction between clay-g-PMMA and PMMA without any interpenetration of grafted and matrix chains. The enhanced miscibility between grafted PMMA and surrounding SAN just began to be destroyed after being annealed for a long time, resulting in the final migration of clay-g-PMMA to the interface of PMMA/SAN (thermodynamic equilibrium state).

中文翻译：

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聚（甲基丙烯酸甲酯）/聚（苯乙烯-共-丙烯腈）共混物中低接枝密度的聚（甲基丙烯酸甲酯）接枝粘土纳米片的选择性定位和迁移

摘要 聚（甲基丙烯酸甲酯）/聚（苯乙烯-共-丙烯腈）（PMMA）的相分离聚合物共混物中具有低接枝密度的聚（甲基丙烯酸甲酯）接枝粘土（clay-g-PMMA）纳米片的定位和迁移/SAN) 进行了调查。粘土纳米片表面接枝PMMA链的接枝密度和分子量分别约为0.04链/nm2和7.8×104，表明接枝链可能呈现蘑菇状分布。随着 PMMA/SAN 共混基质的相分离，共混基质中分散良好的粘土-g-PMMA 纳米片首先位于富含 SAN 的相中，然后逐渐迁移到 PMMA 和 SAN 之间的界面。改性粘土在共混基质中的第一个异常位置可能归因于接枝 PMMA/周围 SAN 链的混溶性引起的粘土-g-PMMA 和 SAN 之间的有利相互作用以及粘土-g-PMMA 和没有接枝链和基质链的任何相互渗透。接枝的 PMMA 与周围 SAN 之间增强的混溶性在经过长时间退火后才开始被破坏，导致粘土-g-PMMA 最终迁移到 PMMA/SAN 的界面（热力学平衡状态）。