Cellulose (Whatman) 41 filter paper) was grafted under in situ UV radiation with organosilicone monomer 3-(trimethoxysilyl)-propylmethacrylate (silane) at optimized system (30% silane and 30-min irradiation) and obtained enhanced mechanical properties like tensile strength factor (TS = 140%) and elongation at break (Eb = 200%) with 25% polymer loading. To improve the mechanical properties, cellulose was pretreated under UV and gamma radiation at different radiation intensities and was grafted with 30% silane under in situ UV radiation. Although the gamma pretreated grafted sample shows higher polymer loading (PL = 31%), the UV-pretreated grafted sample shows better enhancement of mechanical properties (PL = 33%, TS = 250%, and Eb = 274%). For further improvement, cellulose was pretreated by alkali (5% NaOH) along with UV and gamma radiation with different intensities and grafted with silane under UV radiation. Among the treatments, the alkali +UV-irradiated grafted sample showed the best performance (TS = 260% and Eb = 280%) with 37% polymer loading at 10th UV pass. Water uptake of treated and untreated samples was studied and less water uptake was observed by the treated samples, with carroborates the finding that silane might be deposited or reacted on cellulose backbone of pure cellulose. Copyright © Taylor & Francis, Inc.