Influence of UV-curing conditions on polymerization kinetics and gloss of urethane acrylate coatings

The photochemically curable polymer films were prepared by addition of 2,2-dimethyl-2-hydroxyacetophenone (Darocure 1173) as a radical initiator to aliphatic urethane tetraacrylate Craynor 925. Kinetic study of the UV-curing of these films by medium pressured mercury lamp was performed by means of infrared spectroscopy. The results showed that the photoinitiator concentration, the light intensity, sample coating thickness, presence of air oxygen, as well as the UV light intensity were the most significant factors affecting the polymerization course of UV-cured films. The influence of the sample coating thickness on the kinetics and final gloss were also considerable.

► The curing of a system composed of urethane acrylate oligomer Craynor 925 and photoinitiator (Darocure 1173) was optimized.
► As accepted, the gloss of prepared coatings increased during the curing.
► Final gloss of the cured samples depends on the light intensity and layer thickness.
► The prepared coatings positively influence the colour ink stability of ink jet prints.