Preparation and Properties of Biodegradable Slow-Release PAA Superabsorbent Matrixes for Phosphorus Fertilizers

Biodegradable superabsorbent matrixes for a slow-release fertilizer were prepared by using crosslinked acrylic acid and water-soluble granular phosphorus fertilizer KH₂PO₄. The effects of the amount of crosslinker, initiator and phosphorus fertilizer concentration on water absorption were investigated and optimized. The products show excellent slow release and water-retention capacity, being nontoxic in soil and environment-friendly, and could be useful especially in agricultural and horticultural applications. The results showed that the hydrogel structure and swelling capacity was affected by various factors, such as concentration of crosslinker and initiator, as well as by the amount of KH₂PO₄.