Spectroscopic Characterization of Commercial UV-Curable Gel Polish, Identifying Acrylate Monomers and Additives Using NMR Technique

Abstract

This study investigates the composition and structure of commercial UV-curable gel polish formulations using advanced spectroscopic techniques. Five commercially available gel polish products and eight raw materials were analyzed using nuclear magnetic resonance (¹H, ¹³C, ³¹P NMR). Spectral comparisons revealed characteristic signatures of acrylates, urethane acrylates and functional additives, including 2-hydroxyethyl methacrylate (HEMA) and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO). Component identification was achieved by matching unique chemical shifts and signal multiplicity with reference raw materials. The results demonstrate that all commercial formulations contained HEMA, a known skin sensitizer, and several incorporated phosphorus-based photoinitiators such as TPO, associated with potential toxicological and environmental concerns. By providing a detailed structural fingerprint of key monomers and additives in UV-curable systems, this study contributes to improving formulation transparency, enabling better risk assessment, and supporting the development of safer alternatives in nail coating technologies.