Alfa fiber/polypropylene composites: Influence of fiber extraction method and chemical treatments

Abstract

ABSTRACTAlfa fiber/polypropylene composites were manufactured using twin‐screw extrusion. Fibers were extracted using alkaline and steam explosion methods. Three chemical treatments were also applied to the alkaline‐extracted fibers: stearic acid (SA), and potassium permanganate dissolved in water (KW) and in acetone (KA). Finally, thermal annealing was applied to the composites. The results indicate that composites with steam‐exploded fibers had a significantly higher melt flow index than composites with alkaline‐extracted fibers. Moreover, the incorporation of fibers into the matrix increased the Young's modulus, where the optimum results were obtained utilizing the alkaline‐extracted fibers. Both extraction methods also significantly decreased the water uptake, especially the steam explosion. The three chemical treatments increased the melt flow index and conversely decreased the tensile strength and Young's modulus. In addition, KW treatment decreased the water uptake. Finally, thermal annealing increased the tensile strength and Young's modulus of composites with SA‐treated fibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47392.