Graft copolymers of natural fibers for green composites

•Hydrophobic vinyl monomer was successfully bonded to the natural cellulose polymer using graft copolymerization.•Optimization of different reaction parameters to gain maximum percentage of grafting.•Increase in physico-chemical properties of grafted natural cellulose polymer.•Enhancement in tensile properties of pristine polymer after graft copolymerization of natural cellulose polymer. In the present study, free radical induced graft-copolymerization of natural cellulosic polymers (Grewia optiva) has been carried out to develop the novel materials meant for green composites and many other applications. During the graft copolymer synthesis diverse reaction parameters that significantly affect the percentage of grafting were optimized. The structural, thermal and physico-chemical changes in the natural cellulosic polymers based graft copolymers have been ascertained with scanning electron micrography, Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA) and swelling studies. The swelling studies of the grafted cellulosic polymers have been carried out in different solvents to assess the possible applicability of these natural polymers. Green composites were also prepared using raw/grafted cellulosic polymers. It has been found that grafted polymers (Grewia optiva) based green composites gives better tensile properties than the parent natural cellulosic polymers based composites.