Journal of Scientific Research and Reports

Aims: To prepare a cellulose-based poly(acrylic acid) hydrogel from sugarcane bagasse by free-radical polymerization and to characterize the extracted cellulose, hydrogel morphology, thermal behaviour and 24-h water uptake.

Study Design: Experimental laboratory study.

Place and Duration of Study: Department of Chemistry, Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana, India.

Methodology: Cellulose was extracted from sugarcane bagasse by sequential dilute-acid treatment, alkaline delignification and acidified sodium chlorite bleaching. A hydrogel was prepared from 0.90 g extracted cellulose and 3.0 mL acrylic acid using sodium persulfate as initiator and N,N′-methylenebisacrylamide as crosslinker. Solid-state 13C CP/MAS NMR was used to compare untreated bagasse and extracted cellulose; hydrogel morphology, X-ray diffraction and thermogravimetric behaviour were also evaluated. Swelling was measured gravimetrically after 24 h in distilled water using three 0.50-g dry specimens.

Results: The gravimetric cellulose extraction yield was approximately 30%. NMR showed attenuation of lignin- and hemicellulose-associated resonances after extraction, while SEM showed a transition from fibrous cellulose to an irregular porous morphology after hydrogel formation. XRD retained cellulose-I-related reflections but also showed additional sharp reflections in the hydrogel that were not assigned unambiguously. Under nitrogen, the extracted cellulose and hydrogel had residues of 17.66% and 32.04%, respectively, at 600 °C. The 24-h swelling degree was 900 ± 40%, equivalent to a water uptake of 9.0 ± 0.4 g g−1 (n = 3 specimens).

Conclusion: Sugarcane-bagasse-derived cellulose was used to prepare a water-absorbing hydrogel material under the reported synthesis conditions. The present data support a biomass-valorization route and quantify 24-h water uptake, while direct grafting efficiency and equilibrium swelling kinetics were not determined.