Controlled release formulations were prepared by using commercially available poly(methyl vinyl ether-alt-maleic anhydride) (I) and 2,4-dichlorophenoxy acetic acid herbicide (2,4-D). The copolymer (I) was reacted with various diamines to produce amido-amine containing carboxylate copolymers. The produced copolymers were reacted with the acid chloride of herbicide 2,4-D as model herbicide for carboxylic group functionalized herbicides. The formulations produced were characterized by IR and elemental analyses. The release of the herbicide 2,4-D from the formulations was studied under different aqueous medium conditions and the effect of copolymer microstructure on release profiles was investigated.