Structure-Property Relationship in Antimicrobial Polymers Synthesized by Chemo-Enzymatic Route

Anti-microbial polymers are an important class of materials which are catching attention of the researchers worldwide in view of the fast increase in resistance to antibiotics by the microbes. Factors like molecular weight of the polymer, hydrophobic nature or length of the side chain, and nature of the cation and anion mainly affect their efficacy. Structure-property relationship in polymers also affects their activity, and present work reports synthesis of a series of new class of anti-microbial polymers by chemoenzymatic route initially employing lipase as the biocatalyst. The pendant nitro groups of the monomer were reduced to amino groups and the monomer was subsequently polymerized and the amino groups were quaternized using different alkyl bromides. The bromide counter anions on the polymer were exchanged with OH-, CF3COO-, Cl-or HSCH2COO− to generate a series of new polymers. Properties of the synthesized polymers were characterized by XRD, SEM, FT-IR and NMR spectroscopy. Anti-microbial activity of these new polymers were also investigated against gram (-) bacterium (Citrobacter freundii) and fungi.