Abraham Jiji, Maria Hanna J, George Soney C, Kalarikkal Nandakumar, Thomas Sabu
International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, P.D. Hills, Kottayam, Kerala 686560, India.
Phys Chem Chem Phys. 2015 May 7;17(17):11217-28. doi: 10.1039/c5cp00719d.
The transport behaviour of some aromatic and aliphatic solvents through carbon nanotube filled styrene butadiene rubber composites has been investigated. The aim of the present work is to investigate the role of the sorption technique in analysing the compatibility and the reinforcing effect of MWCNTs as a filler in the SBR matrix. It also focuses on the investigation of the relationship between the dispersion of CNTs in the SBR matrix and its transport behaviour. The diffusion and transport of organic solvents through the membranes have been investigated in detail as a function of CNT content, nature of solvent and temperature in the range of 28-60 °C. Solvent uptake, diffusion, sorption and permeation constants were investigated and were found to decrease with the increase of CNT loading. Transport properties could be related to the morphology of the nanocomposites. At high concentration CNT particles form a local filler-filler network in the rubber matrix. As a result, the transport of solvent molecules through the polymer is hindered. The rubber-solvent interaction parameter, enthalpy and entropy of sorption have also been estimated from the transport data. The values of rubber-solvent interaction parameters obtained from the diffusion experiments have been used to calculate the molecular mass between the crosslinks of the network polymer. The better reinforcement at higher filler loading was confirmed from the cross-link density values. The extent of reinforcement was evaluated using Kraus and Cunneen and Russel equations. The Affine and Phantom models for chemical crosslinks were used to predict the mobility of the crosslinks. The Phantom model gave better fitting indicating that the chains can move freely through one another, i.e. the junction points fluctuate over time around their mean position without any hindrance from the neighbouring molecule. The diffusivity datas of the systems have shown dependence on the temperature and microstructure of the nanocomposite. Finally, the diffusion data have been compared with theoretical predictions.
研究了一些芳香族和脂肪族溶剂在碳纳米管填充丁苯橡胶复合材料中的传输行为。本工作的目的是研究吸附技术在分析多壁碳纳米管（MWCNTs）作为丁苯橡胶（SBR）基体填料的相容性和增强效果方面的作用。它还着重研究碳纳米管在SBR基体中的分散与其传输行为之间的关系。详细研究了有机溶剂在28 - 60℃范围内通过膜的扩散和传输，作为碳纳米管含量、溶剂性质和温度的函数。研究了溶剂吸收、扩散、吸附和渗透常数，发现它们随着碳纳米管负载量的增加而降低。传输性能可能与纳米复合材料的形态有关。在高浓度下，碳纳米管颗粒在橡胶基体中形成局部填料 - 填料网络。结果，溶剂分子通过聚合物的传输受到阻碍。还从传输数据估计了橡胶 - 溶剂相互作用参数、吸附焓和熵。从扩散实验获得的橡胶 - 溶剂相互作用参数值已用于计算网络聚合物交联点之间的分子量。从交联密度值证实了在较高填料负载下有更好的增强效果。使用克劳斯、坎宁和拉塞尔方程评估增强程度。使用化学交联的仿射模型和虚拟模型来预测交联点的迁移率。虚拟模型拟合效果更好，表明链可以彼此自由移动，即连接点在其平均位置周围随时间波动，不受相邻分子的任何阻碍。系统的扩散系数数据显示出对纳米复合材料温度和微观结构的依赖性。最后，将扩散数据与理论预测进行了比较。
