Effect of temperature on copolymerization parameters of hydroxyethyl acrylate and methyl methacrylate

The copolymerization of 2-hydroxyethyl acrylate (HEA, M-1) and methyl methacrylate (MMA, M-2) in cyclohexanone was studied. The multiple experiments of solution copolymerization with low conversion were carried out at two sensitive composition feed points at 60, 80, 100, 120 and 140 degrees C, respectively. The composition of the copolymers was analyzed by H-1-NMR. The reactivity ratios which were estimated by the Error-in-Variable Method (EVM) of Mayo-Lewis equation were found to be r(1) = 0.328, r(2) = 1.781 for 60 degrees C; 0.375, 1.709 for 80 degrees C; 0.406, 1.654 for 100 degrees C; 0.439, 1.540 for 120 degrees C and 0.455, 1.400,for 140 degrees C, and the 95% joint confidence intervals of the reactivity ratios were also determined. According to r(1) and r(2), Arrhenius relations and the activity energy difference between the home-and cross-propagation were calculated.