Multiscale Reinforcement System

1. Introduction

Carbon nanotubes (CNTs) have widely been used as reinforcement in polymer matrix–based composites. This is because of their unique properties such as mechanical, thermal, and electrical properties. In addition, carbon nanotubes have high aspect ratios and more surface area per gram which make them suitable for their use as multi-functional reinforcement materials in polymer matrixes , .

The performance of a composite material system depends mainly on the interfacial properties of the reinforcement and the matrix material . The interface controls the interactions between the reinforcement and the matrix and thus affects the mechanical property of the composites. The stress transfer from the matrix to the reinforcement occurs through the interface. The fiber/matrix adhesion plays an important role in the load transfer ability of the interface .

Composites with multiscale reinforcements are typically those which contain nano- and micro-scale reinforcements simultaneously . The mechanical properties of the multiscale reinforcement system which contain a micro-scale fiber and nano-scale CNT have been found to be improved , , , , . Composites

In this study, the CNT/ramie fiber hybrid multi-scale reinforcement system has been used to investigate the effect of this system on the mechanical and interfacial properties with an epoxy matrix. A simple chemical method is proposed to graft CNT on the surface of ramie fiber. The CNT has been grafted on ramie fiber by means of a silane coupling agent. The composite plates were fabricated using vacuum infusion method. The study aims to explore the CNT grafting mechanism on ramie fiber, and the effect of the hybrid reinforcement on the mechanical and interfacial properties was