Bioengineering Functional Copolymers. XV. Synthesis and Characterization of Poly(N-isopropyl acrylamide-co-3,4-dihydro-2H-pyran-alt-maleic anhydride)s and Their PEO Branched Derivatives

Abstract

Novel bioengineering functional terpolymers were synthesized by complex-radical terpolymerization of N-isopropylacrylamide (NIPA), 3,4-dihydro-2H-pyran (DHP) and maleic anhydride (MA) with alpha,alpha'-azoisobisbutyronitrile (AIBN) as a radical initiator in 1,4-dioxane at 65 degrees C under nitrogen atmosphere. Structure compositions and composition-property relationships of terpolymers, and the monomer reactivity ratios were investigated by (1)H ((13)C) NMR spectroscopy, DSC and TGA thermal analysis. The monomer reactivity ratios were determined by modified methods of Jaacks and Kelen-Tudos using (1)H-NMR analysis data: r(1) = 1.14 and r(2) = 0.06 (by (1)H-NMR) and r(1) = 1.07 and r(2) = 0.04 (by N analysis) for NIPA (M(1)) and MA ... DHP (M(2)) monomer-monomer complex pair. An alpha,omega-hydroxy-methoxy-polyethylene oxide branched derivative was synthesized by grafting (esterification) of anhydride units of the terpolymer. Investigation into the factors affecting the antitumor activity revealed that terpolymers containing a combination of H-bonded ionizable amide and carboxylic groups exhibited higher antitumor activity, towards SCLC cancer cells. (c) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4285-4295, 2010