The Registration Evaluation Authorization and Restriction of Chemicals (REACH) regulation in Europe and regulations imposed by the Environmental Protection Agency (EPA) in the United States have motivated scientists and technicians to adopt safer routes for developing coating formulations. In the coatings industry, UV light-cured coatings (UVCs) have enjoyed tremendous success in the past few decades. UVCs are gaining incredible attention due to inherited benefits such as energy efficiency, low work space requirements, fast and ambient curing temperatures, minimized VOC emissions and superior surface attributes. Although introduced in the early 70s, UVC technology is still evolving, with new commercial products appearing among conventional polymer-based coating products. Numerous curing techniques involving different photoinitiators (PIs) and crosslinkers have been postulated to negate the general perception in the coatings industry that low-temperature curing/hardening means inferior crosslinking and coating strength. The free radical class of PIs has been widely accepted among commercially available PIs, as these can be used with both acrylates and unsaturated polyesters. Similarly, multi-functional low-, medium- and high-molecular-weight acrylates have been introduced to impart the desired level of crosslinking in UVCs. The addition of telechelic silicones in UVC compositions deemed to provide adequate crosslinking anchors along with a flexible inorganic segment. This article explores the possibility of using telechelic silicones in traditional acrylate-based UVC compositions.
An in-depth analysis of cure kinetics of UVCs was conducted using Raman spectroscopic techniques. The surface morphology of the UVC coated substrate was studied with atomic force microscopy (AFM). The hardness and modulus of the siliconized UVC was determined by nanoindentation techniques. Moreover, instrumented nanoscratch tests helped in understanding the adhesive and cohesive modes of failures in siliconized UVC. Attempts have also been made to understand the wear characteristics of the siliconized surface. It is expected that this article will provide readers a good understanding on the properties of siliconized UVC formulations.