Fabrication and Application of Eco-Friendly Superabsorbent Composites Based on Cellulose and Coal Gangue

Abstract

Amid the rising trend of using waste to fabricate eco-friendly superabsorbent polymer (SAP), a composite of cellulose-g-polyacrylic acid/coal gangue (CS-g-PAA/CG) was prepared by grafting polyacrylic acid (PAA) on cellulose (CS) and introducing the solid waste coal gangue (CG) as an inorganic component, in this work. The SAP composite’s structure, morphology, and thermal stability were examined, which indicated that the CG–polymeric network interaction was achieved through the electrostatic interactions or the hydrogen bonds. The CS-g-PAA/CG composite possessed an eximious capacity of water absorption, which was 681 g/g in distilled water and 81 g/g in NaCl solution with a mass fraction of 0.9%. What’s more, in contrast with a blank sample (only containing soil), the CS-g-PAA/CG significantly improved the soil’s water retention efficiency, which was determined by plant pot experiments. Furthermore, the SAP promoted the plant’s growth as well as could be degraded by about 35.39% in 28 d which was proved by the cultivation experiments. With its significant water absorbency, water retention, plant growth promotion performance, and degradability, CS-g-PAA/CG may have great application potential as a water retention agent or soil conditioner to improve on the growth of the plant.

Keywords: superabsorbent, gangue, cellulose (CS), water retention, biodegradable, plant growth