Influence of Darocur 1173 photoinitiator on the photocrosslinking and properties of UV-cured coatings based on an epoxidiacrylate oligomer and hexanediol diacrylate monomer

Abstract

The influence of Darocur 1173 (D. 1173) photoinitiator content on the photocrosslinking of the coatings based on an epoxy diacrylate oligomer (EDA), hexanediol diacrylate monomer (HDDA) and properlies of UV cured coatings have been studied. The fast conversion of acrylate groups and UV crosslinking of the coatings were shown by IR- spectroscopy analysis and gel fraction determination, respectively. It was found that there was an optimal relationship between conversion of acrylate groups, as well as the hardening rate of the coatings and contents of D.1173, ranging from 0 to 2 % of total amount of EDA and HDDA, under UV exposure. The optimal content of D.1173 was determined to be 1 % and the UV curing of the coating having the weight ratio of the constituents EDA/HDDA/D.1173 = 50/50/1 occurred very fast, leading to formation of a high performance UV cured coating which can be used in different sectors of applications as decorative, protective coatings or adhesives.