Synthesis and Characterization of Superabsorbent Bio-Based Hydrogels from Pandanus tectorius Leaf Cellulose through Ester-Based Crosslinking for Water-Holding Applications

Abstract

The development of sustainable hydrogels from renewable biomass has attracted increasing interest for environmental and agricultural applications. In this study, cellulose isolated from Pandanus tectorius leaves was utilized as a precursor for the synthesis of carboxymethyl cellulose (CMC), which was subsequently used to prepare hydrogels through ester-based crosslinking. A dual-network hydrogel structure was formed by blending CMC with hydroxyethyl cellulose (HEC), followed by esterification with citric (CA), fumaric (FA), and malic (MA) acids. Structural characterization using FTIR confirmed successful carboxymethylation and ester crosslinking within the polymer network, while SEM revealed a porous morphology favorable for water diffusion. The synthesized hydrogels exhibited gel fractions of 67–89%, swelling ratios of 578–4163%, and maximum degradation temperatures of 311–428°C. The CMC/HEC-MA hydrogel at a 15% crosslinker concentration demonstrated the most balanced combination of swelling capacity, gel fraction, and thermal stability. Owing to their high water-retention capability, porous structure, and biodegradability, these hydrogels show strong potential as superabsorbent materials for soil moisture conservation, controlled water release in agriculture, drought mitigation, and sustainable water management. These findings highlight the potential of biomass-derived hydrogels to support SDG 2 (Zero Hunger) by improving agricultural water retention, SDG 6 (Clean Water and Sanitation) by promoting efficient water management and treatment, and SDG 12 (Responsible Consumption and Production) by transforming renewable biomass resources into sustainable value-added materials.