Effect of a New Composition Ratio and of a New Chemical Treatment on Natural Alfa Fiber/polypropylene Composites Manufacturing and Their Mechanical Properties

In the present research, our aim is to study effects of alfa fiber content, alkali, maleic anhydride grafted polypropylene (MAPP), and the combined treatment (alkali and MAPP) on the tensile and flexural behavior of alfa fiber-reinforced polypropylene (PP) composites. These composites were produced using a single-screw extruder followed by an injection molding process. Both fibers and composites were characterized using optical and SEM microscope in order to evaluate the interfacial adhesion between the fibers and the matrix. From the main results, the tensile modulus and flexural strength of 30% untreated Alfa fiber/PP composites were found to increase significantly compared to those of PP. Meanwhile, there is no significant increase in terms of the tensile strength and the flexural modulus. Moreover, the composites with a combined treatment have shown significant effect on the tensile and flexural properties compared to untreated composites and the treated ones. The SEM observation of the morphology of alkali treated fibers exhibited an increase in the surface roughness because the removal of impurities. In addition, SEM photos of the fractured surface of composites reveal the improvement of the fibers and PP matrix interface quality by treatments, in particular the combined treatment.