Journal of Polymer Science Part A: Polymer Chemistry, Vol.39, No.21, 3716-3725, 2001
Studies on copolymerization of N-isopropylacrylamide and glycidyl methacrylate
Free-radical homopolymerization of N-isopropyl acrylamide (NIPA, monomer 1) and copolymerizations of NIPA with glycidyl methacrylate (GMA, monomer 2) were conducted in deuterated dioxane at 70 degreesC. The conversion of the monomers was followed by H-1 NMR spectroscopy. After the polymerization reactions the polymers were precipitated and analyzed. Reactivity ratios were determined using both Fineman-Ross and extended Kelen-Tudos methods. Values obtained by these two methods were r(1) = 0.39, r(2) = 2.69 and r(1) = 0.30, r(2) = 2.66, respectively. In both cases, r(1r2) similar to 1, which is indicative of an ideal copolymerization resulting in a first-order Markov distribution of the monomers in the final copolymer. The compositional heterogeneities of the polymers were estimated by following the instantaneous copolymer compositions as functions of conversion. Given the different reactivities of the two monomers it is concluded that a copolymer with a homogeneous distribution of monomers may be obtained not by a batch reaction, but by slowly and continuously adding GAIA into the polymerizing reaction mixture.
Keywords:homopolymerization;copolymerization;N-isopropyl acrylamide;glycidyl methacrylate;Fineman-Ross method;extended Kelen-Tudos method;Markov distribution