Abstract

Background: Polymers supporting chemicals used in agriculture have recently been developed to overcome the serious environmental problems of conventional agrochemicals. The success of these formulations is based on a suitable choice of polymer support. Degradable polymeric hydrogels are of particular interest. The gradual release of the bioactive agent can be achieved by hydrolytic or enzymatic cleavage of the linking bond. Results: In this context, poly[(1-vinyl-2-pyrrolidone)-co- (2-hydroxyethyl methacrylate)] [poly(NVP-coHEMA)] has been used as a bioactive carrier reagent. Herein, we report a controlled-release system with the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) using an ultrafiltration system. Hydrolysis was studied by testing the release at various pH values. A high release with poly(NVP-co-HEMA)-2,4-D was observed at pH = 7 and 10 after two days (Z = 2). The release percentage of copolymer-herbicide increased at pH = 10. It showed release values between 79.0 and 94.5%. Poly(NVP-co-HEMA)-herbicide can release a bioactive compound in aqueous solution at pH = 3, 7 and 10. Conclusion: Based on the results of homogeneous hydrolysis, it is argued that the herbicide release rate depends on the pH of the reaction environment. This functional polymer could be employed as a biodegradable material for applications in agrichemical release. © 2008 Society of Chemical Industry.