Mechanical and abrasion characteristics of low-content Kevlar-29 fibre reinforced epoxy composites for lightweight structural applications

Abstract

High fibre loading has been established as one of the major causes of agglomeration and fibre touching that usually resulted to low-strength in some polymer-based composites due to weak interfacial bonding and adhesion. However, the development of lightweight and high-strength composites is critical for modern structural applications in aerospace, automotive, defense and civil engineering among other allied areas. Hence, in this research, Kevlar fibres were incorporated into epoxy resin within the selected low fibre contents using the stir casting method. The evaluated results indicated that mechanical and physical properties yielded significant performance improvements with increasing fibre content. Ultimate tensile strength increased from 10.93 MPa in the control sample to 26.78 MPa at 10 wt%, while impact strength improved from 16 J/mm² to 28 J/mm². Flexural strength rose from 43.68 MPa to 79.95 MPa, accompanied by enhancements in hardness and wear resistance. Moreover, thermal conductivity decreased with higher fibre loadings, confirming the insulating properties of Kevlar-epoxy composites. The results show that 10 wt% is the optimal reinforcement threshold where mechanical and abrasion resistance synergy is maximized without compromising the lightweight advantage, providing essential design data for weight-critical structural applications with good insulating properties.