Tensile and Flexural Properties of Silica Nanoparticles Modified Unidirectional Kenaf and Hybrid Glass/Kenaf Epoxy Composites.

Aidah Jumahat,Napisah Sapiai,Mohamad Midani,Anish Khan,Mohammad Jawaid

doi:10.3390/polym12112733

Abstract

This paper investigates the influence of silica nanoparticles on the mechanical properties of a unidirectional (UD) kenaf fiber reinforced polymer (KFRP) and hybrid woven glass/UD kenaf fiber reinforced polymer (GKFRP) composites. In this study, three different nanosilica loadings, i.e., 5, 13 and 25 wt %, and untreated kenaf fiber yarns were used. The untreated long kenaf fiber yarn was wound onto metal frames to produce UD kenaf dry mat layers. The silane-surface-treated nanosilica was initially dispersed into epoxy resin using a high-vacuum mechanical stirrer before being incorporated into the UD untreated kenaf and hybrid woven glass/UD kenaf fiber layers. Eight different composite systems were made, namely KFRP, 5 wt % nanosilica in UD kenaf fiber reinforced polymer composites (5NS-KFRP), 13% nanosilica in UD kenaf fiber reinforced polymer composites (13NS-KFRP), 25 wt % nanosilica in UD kenaf fiber reinforced polymer composites (25NS-KFRP), GKFRP, 5 wt % nanosilica in hybrid woven glass/UD kenaf fiber reinforced polymer composites (5NS-GKFRP), 13 wt % nanosilica in hybrid woven glass/UD kenaf fiber reinforced polymer composites (13NS-GKFRP) and 25 wt % nanosilica in hybrid woven glass/UD kenaf fiber reinforced polymer composites (25NS-GKFRP). All composite systems were tested in tension and bending in accordance with ASTM standards D3039 and D7264, respectively. Based on the results, it was found that the incorporation of homogeneously dispersed nanosilica significantly improved the tensile and flexural properties of KFRP and hybrid GKFRP composites even at the highest loading of 25 wt % nanosilica. Based on the scanning electron microscopy (SEM) examination of the fractured surfaces, it is suggested that the silane-treated nanosilica exhibits good interactions with epoxy and the kenaf and glass fibers. Therefore, the presence of nanosilica in an epoxy polymer contributes to a stiffer matrix that, effectively, enhances the capability of transferring a load to the fibers. Thus, this supports greater loads and improves the mechanical properties of the kenaf and hybrid composites.

Highlights

Kenaf fiber is one of the natural fibers that always receives much attention due to its potential as a natural-based reinforcement material in the composites industry
Kenaf fibers are extracted from the stem of the kenaf (Hibiscus cannabinus) plant belonging to the Malvaceace family [1,2,3,4]
The results indicate that the inclusion of silica nanoparticles improved the tensile and flexural properties of kenaf fiber reinforced polymer (KFRP) and hybrid glass/UD kenaf fiber reinforced polymer (GKFRP) composites

Summary

Introduction

Kenaf fiber is one of the natural fibers that always receives much attention due to its potential as a natural-based reinforcement material in the composites industry. Kenaf is an annual and short-day plant; it can grow to over 3–5 m tall with a woody base within 3–4 months [1,2,3,4]. Due to its high specific strength, low density, renewability, biodegradability and sustainability, kenaf fibers have been touted as an alternative reinforcement material to replace glass fiber. Kenaf fiber composites have potential applications in many composites industries. They can be used as thermal insulation materials, sound-damping and vibration-absorbing materials, construction and building materials, food containers, coarse cloth and fabric, oil- and liquid-absorbent materials, etc. They can be used as thermal insulation materials, sound-damping and vibration-absorbing materials, construction and building materials, food containers, coarse cloth and fabric, oil- and liquid-absorbent materials, etc. [4]

Methods

Results

Conclusion