Biocomposites from abaca strands and polypropylene: Effect of chemical treatment by stearic acid

Abstract

Unidirectional composites of polypropylene (PP), reinforced with abaca fiber was fabricated by compression molding with and without the presence of stearic acid (SA) as a coupling agent. Raw abaca fiber was utilized and four levels of filler loading (10, 20, 30 and 40 wt%) were used during composite manufacturing. Mechanical tests (tensile, bending and impact properties) of the resultant composites were conducted. Based on fiber loading, 30% fiber-reinforced composites had the optimum set of mechanical properties. Optimized abaca fiber was chemically treated with SA to increase its compatibility with the polymer matrix. SA treated abaca fiber-reinforced composites yielded better mechanical properties compared to the raw composites. In order to know more about the fiber-matrix adhesion, scanning electron micrographs (SEM) of the tensile fractured samples showed improved adhesion between abaca and PP matrix upon treatment with SA. Water uptake and simulating weathering test of the composites were also investigated.