Influence of monomer on structure, processing and application characteristics of UV curable urethane acrylate composite coatings

Abstract

Increased interest in the esthetical natural nail coatings have encouraged more in-depth studies particularly of UV curable coatings: their formation, processing, structure, characteristics and removing. Typical requirement for nail coatings is good adhesion, but preferably for the short time of functioning (usual 2-4 weeks). This study investigated the impact of four different monomers (tertiobutyl cyclohexyl acrylate (TBCHA), ethylene glycol dimethacrylate (EGDMA), tetrahydrofurfuryl acrylate (THFA), hydroxypropyl methacrylate (HPMA)) to viscosity of uncured mixture and degree of conversion, mechanical properties, surface gloss, micro hardness and adhesion loss for cured films. Specific coating application requires comparatively high coating flexibility and stability of deformation characteristics. This can be achieved with composition containing 30% of monomer TBCHA, what shows ultimate elongation ϵB = 0,23 - 0,24, modulus of elasticity E = 670-710 MPa and comparatively constant properties in 72 hours (ΔE = 1.3%, ΔϵB=6.0%). A composition with 40% of TBCHA shows the fastest coating destruction achieving adhesion loss within 3 min.