Biologically active organotin polymers.

The synthesis, structure, and properties of polymers in which tin is chemically anchored as tributyltin carboxylate are discussed. A base copolymer with anhydride or carboxyl groups is partially esterified with tributyltin oxide; the free carboxyls are then reacted with diepoxides to yield cross-linked controlled release formulations. The network structure and the separation length and type of epoxide cross-links were altered by changing the degree of esterification of the base polymer, the structure of epoxy monomer, and catalyst. NMR evidence established that rapid exchange exists in tributyltin carboxylates; as a consequence even their interfacial reaction with chloride is fast, producing tributyltin chloride. Biotoxicity data obtained by studying the inhibition of marine and soil bacteria reveal that the type and degree of cross-linking have a significant effect on the size of inhibition zones. Tests in the ocean confirm effective biological activity against marine fouling organisms. Structural correlations with dynamic mechanical and dielectric properties suggest a viable program to investigate the dependence of tributyltin release on polymer matrix properties.