Amino acid vinyl esters: a new monomer palette for degradable polycationic materials

作者：Thomas Glen B; Lipscomb Corinne E; Mahanthappa Mahesh K^*

来源：Polymer Chemistry, 2012, 3(3): 741-750.

DOI：10.1039/c2py00531j

Toward the goal of developing degradable polycationic materials with tunable backbone charge densities and hydrophilicities, we report the optimized syntheses and polymerization activities of a series of N-Boc-protected amino acid O-vinyl ester (BAAVE) monomers derived from Boc-protected glycine, alanine, valine, and proline. The homopolymerization and copolymerization behaviors of these monomers under thermally initiated conventional free radical polymerization conditions are studied. By conducting copolymerizations of (N-tert-butoxycarbonyl) glycine vinyl ester (BGVE) with vinyl acetate (VAc) at various feed ratios and by analyzing the compositions of the resulting polymers produced at 88 degrees C using 1,1'-azobis(cyclohexane-1-carbonitrile) (V-40) initiation, we find that the reactivity ratios are r(BGVE) = 1.61 +/- 0.12 and r(VAc) = 0.82 +/- 0.07. Treatment of poly(VAc-co-BAAVE) with neat CF3COOH selectively unmasks the Boc-protected amine functionalities to furnish cationic poly(VAc-co-AAVE center dot CF3COOH) copolymers. Alternatively, treatment of these random copolymers with methanolic HCl results in the complete hydrolysis of both the Boc-protecting groups as well as the acetate esters, enabling access to well-defined, hydrophilic, polycationic amino acid ester-functionalized poly(vinyl alcohol) materials.

• 出版日期2012