• 文献标题:   Observation of mechanical percolation in functionalized graphene oxide/elastomer composites
  • 文献类型:   Article
  • 作  者:   NAWAZ K, KHAN U, ULHAQ N, MAY P, O NEILL A, COLEMAN JN
  • 作者关键词:  
  • 出版物名称:   CARBON
  • ISSN:   0008-6223 EI 1873-3891
  • 通讯作者地址:   Univ Dublin Trinity Coll
  • 被引频次:   46
  • DOI:   10.1016/j.carbon.2012.05.029
  • 出版年:   2012

▎ 摘  要

We have covalently functionalized graphene oxide (GO) with octadecylamine (ODA) to form GO-ODA. This material can be dispersed in tetrahydrofuran (THF) and subsequently formed into composites with polymers such as thermoplastic polyurethane (TPU). We have characterized the mechanical properties of composites of GO-ODA in TPU. No increase in stiffness was observed at loading levels below 2.5 vol%. Reinforcement appeared to start sharply at this volume fraction and subsequently increased as a power law with increasing volume fraction. This behavior is typical of percolation and shows that the low-strain stress is not increased until the functionalized graphene flakes form a percolating network. Slightly different behavior is observed for properties related to material failure. The ultimate tensile strength increased linearly with graphene content up to the percolation threshold before subsequently falling off. Similarly the strain at break was constant below the percolation threshold but fell off dramatically above it. This work shows the importance of network formation in the reinforcement of elastomeric materials. (C) 2012 Elsevier Ltd. All rights reserved.