Effect of cross linking of PVA/starch and reinforcement of modified barley husk on the properties of composite films

•Palmatic acid was grafted onto barley husk using graft copolymerization.•Effect of cross linking of PVA/St and reinforcement of BH on the properties of films was evaluated.•Tensile strength increased significantly in grafted BH composite film compared to PVA/St film.•Degradation rate of natural BH composite film was faster than PVA/St film. Barley husk (BH) was graft copolymerized by palmitic acid. The crystalline behavior of BH decreased after grafting. Poly vinyl alcohol (PVA)/starch (St) blend film, urea formaldehyde cross linked PVA/St films and composite films containing natural BH, grafted BH were prepared separately. The effect of urea/starch ratio, content of BH and grafted BH on the mechanical properties, water uptake (%), and biodegradability of the composite films was observed. With increase in urea: starch ratio from 0 to 0.5 in the blend, tensile strength of cross linked film increased by 40.23% compared to the PVA/St film. However, in grafted BH composite film, the tensile strength increased by 72.4% than PVA/St film. The degradation rate of natural BH composite film was faster than PVA/St film. Various films were characterized by SEM, FT-IR and thermal analysis.