%0 Journal Article
%T The Effect of H-Bonding on Radical Copolymerization of Maleic Anhydride with N-tert-Butylacrylamide and Its Characterization
%A Ahmet Okudan
%A Ay£¿e Karasakal
%J International Journal of Polymer Science
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/842894
%X The copolymerization reaction between N-tert-butylacrylamide (NTBA) and maleic anhydride (MA) in p-dioxane solution at 65¡ãC using 2,2¡ä-azoisobutyronitrile (AIBN) as an initiator in nitrogen atmosphere was carried out. The chemical structure of the obtained copolymers from a wide range of monomer feeds was determined by elemental analysis (content of N for NTBA units), Fourier transform infrared (FTIR), and 1H-NMR spectroscopy. Also, the amounts of MA units in the copolymers were found using the chemical titration method. An observed tendency toward alternating copolymerization at ¡Ü50 mol% NTBA concentration in monomer feed and relatively high activity of NTBA growing radical was explained by H-bond formation between C=O (anhydride) and NH (amide) fragments during chain growth reactions. Intrinsic viscosity and the molecular weights of the synthesized copolymers depend on the type of comonomer and the amount of NTBA units in the copolymers. The synthesized poly(NTBA-MA)s containing a functional amphiphilic group show both temperature and pH sensitivity and can be used for biological proposes as a physiologically active macromolecular system. 1. Introduction Copolymer is the most successful and powerful method for effecting a systematic change in polymer [1]. Studies have shown that the copolymerization reactions provide an excellent way to prepare macromolecules with specific chemical structures and to control properties such as hydrophilic/hydrophobic balances, polarity, and solubility [2]. Many polymers with reactive functional groups are now being synthesized, tested, and used not only for the macromolecular properties but also for the properties of functional groups. These functional groups provide an approach to a subsequent modification of the polymers for a specific end application [3]. An anhydride group containing maleic anhydride and its polymers has received considerable attention recently because of its varied applications. Maleic anhydride cannot be homopolymerized under normal conditions [4] or hardly homopropagates, which means that maleic anhydride-maleic anhydride diads are virtually absent in the polymer chain [5]. Nevertheless, the reactive MA moiety provides the copolymers with a wide variety of options for chemical modification [6]. Furthermore, it is generally accepted that copolymerization shows a strong tendency toward alternation [7]. Acrylamide and its derivatives can undergo alternating copolymerization with maleic anhydride under the given conditions [8¨C18]. Due to this complex formation, the alternating copolymerization of
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