Effective enhancement of fertiliser release of cellulose derivative based superabsorbent polymer by surface-crosslinking

In this study, the effect of surface crosslinking using epoxidised soybean oil as a crosslinker on the fertiliser release ability of cellulose derivative-based superabsorbent polymer (BioSAP) was evaluated.Before and after introducing the crosslinking agent, the BioSAPs were characterised by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA).The absorption properties of the resulting BioSAPs in the distilled water and NaCl solution were investigated.The fertiliser release ability of BioSAPs into the soil was determined by column extraction in the incubator system.The results showed that the absorption capacity of the surface crosslinked BioSAP by using epoxidised soybean oil (E-BioSAP) was 435 g/g in distilled water and 89 g/g in 0.9% NaCl solution and increased by 5.3 and 12.6%, respectively, when compared with ordinary BioSAP.The release studies revealed that E-BioSAP allowed slow, sustained release rates of fertilisers into the soil.Therefore, the surface crosslinking could promote the development and wide application of BioSAP in agriculture and horticulture.