Study of the Moisture Mitigation and Toughening Effect of Fly‐ash Particles on Sisal Fiber‐Reinforced Hybrid Polypropylene Composites

Abstract

This study focused on developing fly-ash and sisal fiber reinforced hybrid polypropylene (PP) composites. The hybridized composite containing 15 wt.% each of sisal fiber and fly-ash shows highest impact strength of 1.42 kJ/m2, demonstrating an improvement by ~ 125 % and ~ 25 % respectively in comparison to neat PP and composite reinforced with only sisal fiber. Highest and lowest tensile strengths of 37.09 MPa and 24.69 MPa were recorded by composite containing 30 wt.% each of sisal fiber and fly ash with PP and impact modified PP respectively. Flexural strength recorded a greatest value of 44.09 MPa for 30 wt.% reinforced sisal fiber with PP against a lowest estimate of 30.86 MPa for 30 wt.% reinforced fly ash with impact modified PP. The FTIR results confirmed the esterification reaction among sisal fibers and maleic anhydride groups. DMA showed an apparent positive shift in the glass transition temperatures of hybrid composites upon the addition of fly ash. Composite reinforced with 30 wt.% sisal fiber and fly ash exhibited a storage modulus of 13,155 MPa and 8,795 MPa at −80 oC, respectively. Thermal degradation stability of all the hybrid composites improved significantly. The lowest water uptake properties have been demonstrated from the composite with highest fly ash content (15 %).