聚合物分子调控碳纳米管基聚合物复合材料界面性能

项目名称： 聚合物分子调控碳纳米管基聚合物复合材料界面性能

项目编号： No.20874023

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 刘璐琪

作者单位： 国家纳米科学中心

项目金额： 30万元

中文摘要： 如何在宏观尺度充分发挥和利用碳纳米管优异的力、电等功能特性是碳纳米管研究中的热点问题之一。在过去十多年中，基于碳纳米管聚合物纳米复合材料制备和性能研究发展迅速，但材料预期性能远低于理论预测。本项目中我们系统开展了基于聚合物分子结构、分子量、界面区聚合物微结构、两相界面键合方式等对碳管（或石墨烯氧化物）聚合物复合材料界面作用力、弹性模量、拉伸强度、变形模式以及失效机理等研究。发展了一种制备高碳管含量聚合物复合材料新方法。研究结果表明:①具有三维网络结构特征环氧树脂与碳管间可以形成强界面作用力，有利于碳管承担更大载荷，因此材料拉伸强度可高达1.5 GPa，接近由60％T300碳纤维增强的环氧树脂复合条带水平；②聚丙烯在碳管纤维表面会发生异相成核，形成具有不同超分子结构特征的界面穿晶层，其中α8545;型穿晶层，由于径向片晶数量多于切向片晶，较α8546; 和α8544;更有利于界面区应力传递；③聚合物分子量差异对石墨烯氧化物复合薄膜力学性能影响主要体现在韧性和强度两个方面，由于链段缠绕作用高分子量聚乙烯醇有利于延缓材料裂纹扩展；④碳纳米管纤维较碳纤维具有很好增强性能同时，表现出大形变下优异耐压特性。

中文关键词： 碳纳米管；聚合物；纳米复合材料；界面作用；力学性能

英文摘要： Over the past decade, great attention has been paid to fabricate various carbon nanotubes (CNTs) based polymer nanocomposites. Unfortunately, the performance, in particular, the mechanical properties of CNT based nanocomposites is still far beyond the theoretical prediction. Thus, it is a great challengle to fully utilize the extraordianary mechanical,elelctrical properties of individual CNTs at macroscopic levels. In this project, we systematically investigate the effect of polymer chain configuration, polymer molecular weight, microstructures of interfacial phase as well as chemcial bonding types between nanofillers and polymers on the interfaical loading-transfer efficiency, tensiels modulus, tensile strength, and failure mechanism of the nanocomposites. A novel strategy based on liquid infiltration was developed to fabricate high weight content CNTs based composite fibers. The main conclusions include the following: ⑴mechanical tests have revealled the tensile strength of epoxy based CNT composite fibers could reach 1.5 GPa resulting from its strong interfacial adhesion, which is close to that of T300 based epoxy composite tapes; ⑵for iPP-CNTs fiber composites, CNTs fiber could act as a heterogenous nucleating agent to induce transverse crystallization (TC) of iPP at interfacial region. TC layer with negative birefringence (α8545;) is most favorable to the load transfer compared to the TC layer with positive birefringence (α8544;) and mixed birefrigence(α8546;); ⑶the effect of polymer molecular weight on the mechanical peroperties of composites was observed for graphene oxide based PVA composite films, in which the films with high molecular weight PVA could result in higher tensile strength and toughness owing to the retardance of crack propogation; ⑷different from conventional carbon fiber, the CNT fibers could continuously carry load at large strain without permanent deformation and fracture in composites. The intrinsic remarkable flexibility of CNTs together with the coupling effect between CNTs and their surrounding polymers would result in these distinct features.

英文关键词： carbon nanotubes;polymer;nanocomposites;interfaical interaction; mechanical properties