Journal of Polymer Science Part A: Polymer Chemistry, Vol.32, No.13, 2565-2576, 1994
Synthesis and Kinetics of Polymerization of Unsaturated Monomers with Oh Groups in Their Structure - 1.3-Hydroxyneopenty Acrylate
The synthesis of new unsaturated monomers containing functional groups has been theoretically analyzed by considering a simple kinetic scheme. In the reactions between acetyl and acryloyl chloride with neopentylglycol, it was shown that the comparison between theoretical and experimental results, does not allow us to conclude that the two rate constants controlling the reactions are equivalent. Kinetic experiments of the polymerization of 3-hydroxyneopentyl acrylate were carried out in benzene and 1,4-dioxane solution at different temperatures. Dilatometric techniques and nonlinear least-squares methods were used to obtain kinetic data and to determine the kinetic constants, respectively. The values of k(p)/k(t)(1/2) for this monomer were found higher in dioxane than in benzene due, probably, to the fact that in the last solvent the polymerization is heterogeneous. The activation energy, determined by using different values of k(p)/k(t)(1/2) was found 7.6 kcal/mol. The stereostructure of the polymers derived from 3-hydroxyneopentyl acrylate and 3-acetoxyneopentyl acrylate was determined by C-13-NMR spectroscopy from the analysis of the resonance signals belonging to the carbonyl groups, obtaining Values for the fraction of isotactic dyads in the range 0.36 +/- 0.03 for both polymers. Finally, the glass transition temperatures of both polymers, determined calorimetrically, were found 281 and 255 K, respectively.
Keywords:RADICAL POLYMERIZATION;2-HYDROXYETHYL METHACRYLATE;RATE CONSTANTS;POLYMERS;TERMINATION;COPOLYMERS;INITIATION