Biocides, polymer-bound

Design of polymer-bound fungicides can accommodate a slow release mechanism or a permanently attached biocide. The chemical linkages used to attach fungicides to polymers could either be hydrolyzable or nonhydrolyzable depending on the type chemical... 

The results of experiments of the type summarized in Table 8 suggests that polymer-bound biocides can be active under a variety of conditions. As expected, the polymeric systems are usually not as active as the free fungicide, presumably either because the concentration of free biocide is lower in the polymeric cases or because the Inherent activity of the macromolecu-lar biocide is less than the free biocide. 

M. Hartmann, D. Kohrs, and K. Wermann. Biocidal polymers. X. Synthesis and hydrolytic behavior of polymers with pendantly bound 3-amino-1,2,4-triazole. Acta Polym., 36 185-187, 1985. 

Film-forming biocidal polymers useful in marine antifouling compositions selected from trialkyltin groups chemically bound to homo- and copolymeric chains of organotin acrylate were prepared by various methods such as (1) the polymerization of trialkyltin acrylate or methacrylate monomers, (2) chemical modification of functionalized polymer as P(S-MA) with bis(tributyltm) oxide, (3) grafting or blending of the polymers, e.g., PVC, with trialkyltin acrylate (Scheme 3.23) [262]. 

The other example, a polymer-bound fungicide, is found in the copolymerization of pentachlorophenyl acrylate with vinyl acetate and ethyl acrylate. This pentachlorophenol-based product could have use as an anti-fouling agent in marine coatings. In this case it was necessary to copolymerize with ethyl acrylate. The homopolymer was found to be too hydrophobic to allow decomposition of the polymer and allow release of the active agent in sufficiently high concentrations to have the appropriate biocide effect. 

Organotin polymers containing one carboxyalkyl group bound to the tin atom in each recurring monomer unit are obtained by polymerization of an organotin acid of the type Sn[(CH2)mCOOH]4. in aqueous medium at 60 °C. The powdery products are used as biocides and stabilizers for synthetic polymers 81). 

A more recent important development in this field to decrease the rate of antifouling decay is the synthesis and use of polymeric materials containing organome-tallic toxicants chemically bound to the polymer backbone to provide a relatively low dose level of biocides and hence to extend the effective lifetime of antifouling protection [263-273]. 

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