Macromolecules, Vol.29, No.5, 1728-1733, 1996
Synthesis and Polarity of Acrylate Polymers with Long Hydrophilic Side-Groups
The kinetic aspects of the radical polymerization of triethylene glycol monoacrylate are studied finding that the values of k(d)/k(t)(1/2) are in the range 0.17-0.40 L(1/2)/mol(1/2) s(1/2) at temperatures between 50 and 65 degrees C. The values of the activation enthalpy, Delta H**, and activation entropy, Delta S**, of the global process amount of 11.0 kcal mol(-1) and -28.3 cal mol(-1) K-1, within the range reported for other acrylate polymers. Mean-square dipole moments per repeating unit, [mu(2)]/x, were determined from measurements of dielectric permittivities in dilute dioxane solutions. The results at 30 degrees C were [mu(2)]/x = 7.97 D-2 and 10(3) d ln [mu(2)]/dT = 0.85 K-1. Values of dipole moments associated with the conformations of the side groups range from 0.2 to 5 D, and hence a combination of standard matricial products and Monte Carlo techniques were used to evaluate by the rotational isomeric state model the dipolar correlation coefficient of the chains. Good agreement between theoretical and experimental results was found using the set of statistical weights utilized for other acrylate polymers with short side groups.
Keywords:DIPOLE-MOMENTS