Preparation of rapidly absorbing bagasse cellulose-based composite superabsorbent material with semi-interpenetrating networks and its water absorption mechanism.

Biomass-based superabsorbent materials have gained widespread attention for their biocompatibility and high-water absorption capacity in hygiene products. However, slow liquid absorption rate and inadequate salt resistance limit their applications. This study prepared a rapid composite superabsorbent (CAAMC/PVA) featuring a semi-interpenetrating polymer network (semi-IPN) by crosslinking biocompatible linear poly (vinyl alcohol) (PVA) with a bagasse cellulose-g-poly(acrylamide-co-acrylic acid)/modified nano-CaCO network (CAAMC). The CAAMC/PVA surface displays intricate pores and a multilayer structure with a water contact angle of 52°, indicating high hydrophilicity and an excellent water absorption rate. The amount and duration of PVA significantly influenced the formation of the semi-IPN structure in CAAMC/PVA. The -OH groups on PVA interacted with CAAMC through hydrogen bonding, facilitating the formation of the semi-IPN and establishing rapid water-absorbing channels. CAAMC/PVA can absorb 290 g/g deionized water, 47 g/g 0.9 wt% NaCl solution, 42 g/g artificial blood, and 27 g/g artificial urine within 1 min, outperforming some commercial products. Furthermore, adsorption kinetic and Materials Studio simulations revealed that the -OH groups of PVA and the -COOH groups of AA synergistically enhance the absorption rate, with maximum adsorption energy for water molecules of -3.545 kJ/mol. This study presents a novel strategy for developing rapid composite superabsorbent utilizing waste biomass.