ROLE OF PHOTOINITIATORS IN THE UV CURING OF URETHANE ACRYLATE

Polymeric films were prepared under UV radiation with tetraacrylated urethane oligomer in combination with N vinyl pyrrolidone (NVP) using a set of four photoinitiators (Irg 907, Irg 651, Irg 369, and Irg 184). The study evaluates optimum photoinitiator concentration and radiation dose. Various film properties such as gel content, swelling ratio in acetone, pendulum hardness, tensile strength, and elongation at break were determined. These formulated solutions were coated on wood substrates, and gloss and hardness of the film cured on the wood substrate were determined. Some of these properties are compared with those of the films cured on the glass plates. Irg 369 is found to be the best photoinitiator to produce better films, both on glass plate and on wood substrate.