Macromolecules, Vol.31, No.5, 1542-1547, 1998
Determination of free-radical propagation rate coefficients for cycloalkyl and functional methacrylates by pulsed-laser polymerization
Free-radical propagation rate coefficients (k(p)) for three cycloalkyl methacrylates and two functional methacrylates were measured at temperatures between 30 and 110 degrees C. The data were obtained by analyzing molecular weight distributions of polymer produced by pulsed-laser polymerization - the PLP/MWD technique. Arrhenius parameters were compared with recent results reported for linear and branched alkyl methacrylates, including methyl methacrylate (MMA) and n-dodecyl methacrylate (DMA). The highest k(p) value, for 2-hydroxypropyl methacrylate, is more than twice the MMA value, and is 50% higher than the DMA value at 50 degrees C. The monomer with the lowest k(p) value, isobornyl methacrylate, has a coefficient of similar magnitude to DMA Values for the other three monomers - glycidyl, cyclohexyl, and benzyl methacrylates - are intermediate between these two levels.