Thermo-mechanical performance of Kevlar based hybrid natural fiber composites pre-coated with termite modified epoxy polymer

• Termite Soil is used as epoxy modifier in different weight percentage to develop Kevlar based hybrid composites. • Tested composites revealed the optimal weight percentage of termite content adequately balance thermo-mechanical loading conditions. • Reduction in energy absorption capability of termite filled NFC’s were reported due to induced brittleness • Experimental findings were validated with FEA results. • Fractured sample analysed under SEM depicts fibre pull-out, fibre split and delamination were the significant damage modes. The present study investigates the influence of pre-coating epoxy matrix which is modified through termite soil, a naturally occurring thermal balancer on thermo-mechanical performance of Kevlar-based hybrid natural fiber composites (NFC’s) for the first time. Hybrid composites were developed with varying ratios of 10,20, and 30wt.% of termite filler through hand layup route. Mechanical characterization viz., tensile, flexural and impact studies were caried out along with thermo-gravimetric analysis (TGA) and Differential scanning calorimetry (DSC) studies to assess the thermo-mechanical response of termite composites. Mechanical results revealed that 20wt.% termite content delivers optimal performance. Ultimate tensile strength increased from 26.08±0.78 MPa (pure sample) to 30.86±0.92 MPa, representing an 18.38% improvement, whereas flexural strength witnesses the enhancement of 63.68% which is attributed to improved fiber–matrix adhesion and uniform filler dispersion. Termite filler concentration of above 20wt.% loading shows declined properties due to termite agglomeration. Impact strength shows a monotonic decrease with increasing filler content, indicating reduced energy absorption capacity. Additionally, Finite element modelling was done to check the correlation of findings for tensile and flexural test. Thermal analysis demonstrated improved stability with rise in onset temperature from 319.28°C to 334.36°C and increased char residue from 0.765% to 13.258% at 20wt.% filler, whereas Differential scanning calorimetry (DSC) indicated a significant rise in glass transition temperature (Tg) range from 109.69°C to 146.25°C. Microstructure analysis was carried out for fractured samples to examine the failure modes of termite composites