Improving the Mechanical and Surface Properties of Aramid Fiber by Grafting with 1,4-Dichlorobutane under Supercritical Carbon Dioxide.

Chuyuan Jia,Zhenyu Ma,Yunzhe Du,Yudong Huang,Li Liu,Chengce Yuan

doi:10.3390/ma12223766

Abstract

The mechanical and surface properties of aramid fiber were simultaneously improved by grafting with 1,4-dichlorobutane in supercritical carbon dioxide (scCO2). 1,4-dichlorobutane was penetrated and reacted with heterocyclic an aromatic polyamide backbone along with supercritical CO2 fluids. The surface roughness and surface energy of the modified aramid fiber—which were measured by scanning electron microscopy (SEM) and the dynamic contact angle (DCA) test, respectively—significantly increased. X-ray diffractometer (XRD) measurements indicated that the crystallinity of the aramid fiber obviously increased after treatment in scCO2 under stretching. A single fiber tensile test showed that the tensile strength of the aramid fiber greatly enhanced after the modification due to its improved crystallinity characteristics. Moreover, the monofilament pull-out tests indicated that the interfacial shear strength (IFSS) test of the aramid fiber/epoxy composite increased by 24.3% from 51.30 to 63.91 MPa after the modification. This research provides a novel method for the simultaneous surface modification and mechanical improvement of aramid fiber properties.

Highlights

With the rapid development of the aerospace field, fiber-reinforced, resin-based composite materials have gradually replaced traditional metal materials due to their advantages of low density and high strength
The results showed that PMIA surface morphology, water contact angle, macromolecular interaction, crystal structure, thermal properties and tensile strength changed during supercritical carbon dioxide treatment [20]
The interfacial shear strength (IFSS) of the fiber with epoxy resin increased by 24.3% from 51.29 to 63.91 MPa due to its improved surface aramid the fiber with epoxy resin increased by 24.3% from 51.29 to 63.91 MPa due to its improved roughness and surface energy

Summary

Introduction

With the rapid development of the aerospace field, fiber-reinforced, resin-based composite materials have gradually replaced traditional metal materials due to their advantages of low density and high strength. Structural fibers such as carbon, glass and aramid fibers have been intensively adopted in high-performance applications. Aramid fiber is unique for its inherent “skin-core” structure. The poor compatibility between aramid fibers and resin matrixes, which is due to the inert and smooth surface of the aramid fiber, directly leads to the poor interfacial performance of the composites [1,2]

Methods

Results

Conclusion