Mechanisms of hydrogen evolution and stabilization of UV-cured urethane acrylate resin for coating of optical fiber

Abstract

The mechanism of hydrogen evolution from UV-cured urethane acrylate resin for coating optical fiber was studied using electron spin resonance (ESR) and infrared spectroscopy (IR). The origin of the evolution of hydrogen was presumed to be the thermal oxidation of polyalkyleneglycol chains formed by the photo-degradation of the urethane bond in the resin. The evolution of hydrogen was inhibited by addition of a hindered amine light stabilizer or of a sulfur-containing antioxidant. The stabilization mechanisms of these inhibitors were also studied.