Enhancing aging resistance of glass fiber/epoxy composites using carbon nanotubes

Abstract

An experimental investigation is carried out to examine the effectiveness of carbon nanotubes (CNT) in minimizing the environmental assisted degradation of glass fiber/epoxy composites (GFRP). To this end, CNT modified epoxy is used to fabricate glass fiber/epoxy hybrid composites (CNTGFRP). Experimental results show that the addition of 1 wt% of CNT in conventional GFRP increases the interlaminar shear strength (ILSS) by 36% and decreases the volumetric electrical resistance by 46%. Effect of environmental factors is studied by exposing composite samples to 500 h of accelerated weathering cycle. The exposure to aging cycle not only changes the colour and microstructure, it also increases the ILSS and electrical resistance of GFRP and CNTGFRP composite samples. These changes are primarily attributed to the loss of polymer matrix and improved crosslinking in composites caused by moisture, temperature and UV rays during the aging process. It is recorded that while the deformation in unaged composites is of ductile nature, the aged samples show fiber dominated brittle behavior. Finally, it is shown that the incorporation of CNT in the matrix not only ensures structural integrity but also reduces environmental assisted degradation of conventional glass fiber/epoxy composites.