Molecular Crystals and Liquid Crystals, Vol.688, No.1, 29-35, 2019
Effect of light stabilizers on properties of UV-curable polyurethane acrylates
Typical light stabilizers absorb and block UV rays in the wavelength range of 300-380?nm region. This range overlaps with the UV region, necessary to cure UV-curable coating. By overlapping the same region absorbed by photoinitiators, light stabilizers can disrupt the photo-initiation reaction. Therefore, a proper light stabilizer needs to be selected to avoid wavelength overlap of light stabilizers absorbing or blocking UV rays. In this study, various types of light stabilizers were added to UV-curable coatings in order to improve their weatherability as well as their curing speed. The types of light stabilizers and their concentrations, varying from 0.5, 1.0, and 2.0 phr, were incorporated in order to examine the effects of these parameters on cure profiles. The obtained results suggest that a better performance was achieved for coatings with Tinuvin-400 and Hostavin PR-25 when they were added below 1 phr.