A hydrogel, with water content more than 97.0 wt%, was prepared through crosslinking sodium carboxymethylcellulose (Na-CMC) with AlCl3, The effects of amount of crosslinker, water, Na-CMC and the reaction temperature on modulus and biodegradation of the hydrogel were investigated and optimized. At the same time, the factors of amount of antiseptic, nutriments and different soils on the biodegradation of the hydrogel were also discussed in detail. The results showed that the hydrogel had better biodegradation and strength when the mass ratio of crosslinker to Na-CMC was 0.13 at room temperature. The degradation rate of the hydrogel was enhanced by addition of nutrient element especially by addition of urea. The results of biodegradation in different soils showed sand soil is favorable to degradation of the hydrogel.

A superabsorbent polymer with slow-release phosphate fertilizer was prepared by esterification of polyvinyl alcohol (PVA) and phosphoric acid (H3PO4), which was a slow-release fertilizer at the same time. The product's water absorbency (WA) was about 480 times its own weight if it was allowed to swell in distilled water at room temperature for 24 h. WA under various conditions, such as varying the reaction time, the amount of sodium carbonate (Na2CO3), the reaction temperature, and the concentration of phosphoric acid ([H3PO4]), were investigated and optimized. The optimal sample of the product was characterized by FTIR and elemental analysis. The results showed that phosphoric groups had grafted on PVA molecule chains, and the content of P2O5 in the product was 31.2%. The water retention property and phosphate slow-release mechanism of the product were studied as well.