Constructing covalent interface in rubber/clay nanocomposite by combining structural modification and interlamellar silylation of montmorillonite.
Constructing covalent interface in rubber/clay nanocomposite by combining structural modification and interlamellar silylation of montmorillonite.
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DOI：
10.1021/am504426j
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发表时间：
2014-10
影响因子：
9.5
通讯作者：
Chao Zha;Wencai Wang;Yonglai Lu;Liqun Zhang
中科院分区：
文献类型：
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作者：
Chao Zha;Wencai Wang;Yonglai Lu;Liqun Zhang
强的界面相互作用和纳米分散是聚合物纳米复合材料所必需的，具有良好的力学性能。本文首先对蒙脱土进行了酸处理，使其表面产生更多的硅醇基团。然后通过与硅烷醇基团的共价接枝对γ-甲基丙烯酰氧基丙基三甲氧基硅烷分子（KH 570）进行化学改性。（29）Si和（27）Al魔角旋转（MAS）NMR结果揭示了酸处理后蒙脱土的微观结构变化，证实了酸处理后蒙脱土表面硅醇基团的增加。热重分析表明有机硅烷在蒙脱土表面的接枝量增加。X射线衍射（XRD）结果表明，改性过程将蒙脱土的高度有序的堆积结构转变为高度无序的结构，表明有机硅烷成功地接枝到了结晶片的层间表面。采用丁苯橡胶（SBR）胶乳和蒙脱土接枝水悬浮液共混法制备了SBR/MMT纳米复合材料。在硫化过程中，通过过氧化物自由基引发的反应，改性蒙脱土与橡胶之间建立了共价界面，有效地防止了层聚集。SBR/MMT纳米复合材料中蒙脱土层高度均匀分散，最终实现了共价界面相互作用，表现出良好的性能。
Strong interfacial interaction and nanodispersion are necessary for polymer nanocomposites with expectations on mechanical performance. In this work, montmorillonite (MMT) was first structurally modified by acid treatment to produce more silanol groups on the layer surface. This was followed by chemical modification of γ-methacryloxy propyl trimethoxysilane molecule (KH570) through covalent grafting with the silanol groups. (29)Si and (27)Al magic angle spinning (MAS) NMR results revealed the microstructural changes of MMT after acid treatment and confirmed the increase of silanol groups on acid-treated MMT surfaces. Thermogravimetric analysis indicated an increase in the grafted amount of organosilane on the MMT surface. X-ray diffraction (XRD) showed that the functionalization process changed the highly ordered stacking structure of the MMT mineral into a highly disordered structure, indicating successful grafting of organosilane to the interlayer surface of the crystalline sheets. The styrene-butadiene rubber (SBR)/MMT nanocomposites were further prepared by co-coagulating with SBR latex and grafted-MMT aqueous suspension. During vulcanization, a covalent interface between modified MMT and rubber was established through peroxide-radical-initiated reactions, and layer aggregation was effectively prevented. The SBR/MMT nanocomposites had highly and uniformly dispersed MMT layers, and the covalent interfacial interaction was finally achieved and exhibited high performance.