Structure and Dynamics of the Exfoliation of Layered Nanosilicates in 'Liquid Rubber'

粘土蒙脱土(MMT)是一种常用的化合物，用于医疗和工业生产的改良聚合物材料(复合材料)。全球产量范围以每年百万吨为单位。这种粘土由一堆堆薄薄的硅酸铝组成。通过将这些片材均匀地分布在聚合物基质中，可以将增强的机械性能归档。蒙脱土与“液体橡胶”--低分子末端官能化聚丁二烯--的混合，会导致快速凝胶化和随后的堆叠分层。由于这一过程中的结构尚不清楚，在整个分层过程中，表示粘性尺寸的弹性模量与特征松弛时间的乘积保持不变。据作者所知，在其他材料中没有观察到这种独特的行为，这可能表明一种潜在的新材料类别。有机改性蒙脱土和膨润土(作为模型体系)将通过散射测量(静态和动态光散射、X射线和中子散射)进行研究，并辅之以流变学方法，以检验该体系。在中等粘土装载量时，其性能最佳。了解复合材料的结构和剥离机理是在不损失复合材料材料性能的前提下，将蒙脱土含量提高到较高值的基础。

The clay montmorillonite (MMT) is a frequently used compound for medical applications and industrial production of improved polymeric materials (composite materials). Global production ranges in mega-tons per year. The clay consists of stacks of thin aluminium silicates. By evenly distributing these sheets within the polymer matrix, enhanced mechanical properties can be archived. Mixing of MMT with "liquid rubber", low molecular end-functionalized poly(butadiene), results in a fast gelation and a subsequent delamination of the stacks. Whereas the structure during this process is not known yet, the product of the modulus and the characteristic relaxation time, which shows the dimension of a viscosity, stays constant during this whole delamination process. To the knowledge of the author, this unique behaviour was not observed for other materials and may indicate a potentially new class of materials. Organically modified MMT and laponite (as a model system) will be investigated by scattering measurements (static and dynamic light scattering, X-ray and neutron scattering) and complemented by rheological methods in order to examine the system. Optimum properties are found at intermediate clay loadings. Understanding of structure and exfoliation mechanism is the basis for increasing the MMT content in composites to higher values without the loss of the improved material properties of the composite.