Acrylic monomers propagation/termination constants

The susceptibility of the polymerization of a given monomer to autoacceleration seems to depend primarily on the size of the polymer molecules produced. The high propagation and low termination constants for methyl acrylate as compared to those for other common monomers lead to an unusually large average degree of polymerization (>10 ), and this fact alone seems to account for the incidence of the decrease in A f at very low conversions in this case. 

Detailed data ate available, espedal in several di )ters of two edited books (1) and in a recent moncgraph (2). Few data are known on the photopolymerization itself and larged dqiend cn the prac famulatksi used as well as the experimental conditions. Typically, one photon absorbed can lead to 10000 polymerized double bonds (3). Rate constants of propagation fcp and termination fct for a polyurethane acrylate resin containing an acrylate monomer (weight ratio, 1 1) as reactive diluent are 10 1/mol/s and 3 x lO 1/mol/s respectively (when half of the double bonds have been polymerized) (3). 

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