Banana fiber-reinforced polypropylene nanocomposites: Effect of fiber treatment on mechanical, thermal, and dynamic-mechanical properties

Banana fiber-reinforced nanocomposites were fabricated by melt mixing in a twin-screw extruder followed by compression molding in this study. Maleic anhydride polypropylene copolymer (MA-g-PP) was used as a compatibilizer to increase the compatibility between the PP matrix, clay, and banana fiber to enhance exfoliation of organoclay and dispersion of fibers into the polymer matrix. Variation in mechanical, thermal, and physico-mechanical properties with the addition of banana fiber into the PP nanocomposites was investigated. It was observed that presence 3 wt% of nanoclay and 5 wt% MA-g-PP within PP matrix results in an increase in tensile and flexural strengths by 41.3%, and 45.6%, respectively, compared with virgin PP due to the high aspect ratio of clay stacks in the fully exfoliated nanocomposites. Further, incorporation of 30 wt% banana fiber in PP nanocomposites system increases the tensile and flexural strengths to the tune of 27.1%, and 15.8%, respectively. The morphology of fiber-reinforced PP nanocomposites has been examined using scanning and transmission electron microscopies. Significant enhancement in thermal stability of nanocomposites was also observed due to the presence of nanoclay under thermogravimetric analysis. Dynamic mechanical analysis tests revealed an increase in storage modulus (E') and damping factor (tan delta), conforming the strong interaction between nanoclay/banana fiber and MA-g-PP in the fiber-reinforced nanocomposites systems.