1987 Volume 44 Issue 10 Pages 771-777
The effect of chemical structure of acrylate monomers on their electron beam polymerization behavior has been studied. Structural analysis showed that commercial triacrylates were mixtures of di-, tri-, and tetra-acrylates. Therefore, average numbers of acryloyl groups per molecule deviated from three. However, a monomer containing a greater number of unsaturated groups did not always yield a polymer of higher hardness. Harder polymer was obtained from a hydroxyl-containing triacrylate monomer at a low extent of reaction of carbon-carbon double bonds. The rate of polymerization of a monoacrylate monomer containing a hydroxyl was several times higher than that without hydroxyls. The polymerization proceeded by a radical mechanism. Acceleration of polymerization can be explained by an increase in the number of initiating species by the formation of radicals from the hydroxyl, and by the autoacceleration effect arising from both higher viscosity of the monomer and an increase in viscosity of the reaction system by cross-linking.
