Characterization of banana fiber-reinforced polypropylene composites

The present work deals with effect of coupling agent on banana fiber-reinforced polypropylene (PP) composites. Banana fiber-reinforced polypropylene composites were prepared using twin screw extruder with coupling agent and also without coupling agent. The mechanical properties of coupled composites like tensile, flexural and impact strength revealed significant enhancement compared to the uncoupled composites. The failure of uncoupled composites is mainly because of minimum stress development at the interface of composites due to the distribution of load transfer along the fiber. Thermal stability of the banana fiber, polypropylene and banana fiber-reinforced with PP composites was investigated using thermo-gravimetric analysis and found that degradation temperature of the fiber increased in coupled composites. Fourier transform infrared spectroscopy analysis of samples with and without coupling agent was performed to examine respective functional group present in the composites. The encapsulation of filler material by polymer matrix may be the probable reason for coupled composites to absorb moisture content as revealed from moisture studies. Morphological studies of tested samples were made using scanning electron microscope which indicates improved adhesion between banana fiber and polypropylene.