UV-curable powder transparent coatings based on oligo(meth)acrylic resins

Abstract

Polyacrylic resins containing glycidyl methacrylate (GMA), methyl methacrylate (MMA) and n-butyl acrylate (BA) in various molar ratios were obtained. Triaryl sulfonium hexafluorophosphate was used as a photoinitiator and reacted with the epoxy groups of GMA. The relationship between the chemical structure of polyacrylic resins and the parameters of the UV curing reaction and the functional properties of powder coatings was investigated. The appearance and mechanical properties of the coatings were determined based on thickness, gloss, roughness, deformability, scratch resistance, adhesion to steel, hardness, and water contact angle. DMA was used to assess the cross-link density. Powder coatings with good physical and mechanical properties and curing time of 70 s were obtained.

Preparation and Characterization of Duplex PEO/UV-Curable Powder Coating on AZ91 Magnesium Alloys

“…The acrylic resin used to synthesize the UV-cured powder coating is a statistical copolymer composed of three types of mers: glycidyl methacrylate, methyl methacrylate, and n-butyl acrylate (Figure 10). The structure and properties of the resin synthesized and used to cover AZ91 magnesium alloy in this work have been previously examined (using, among others, 1 H-NMR and FT-IR spectroscopy) and presented in our work [35].…”

“…Standard powder coating systems are cured at high temperatures (180-200 • C) contributing to high energy consumption, which generates high costs. The current trend in the powder coating industry is low temperature, including UV-cured systems (cured at 160 • C and below) [31][32][33][34][35]. This is an important aspect with respect to the reduction in production costs, environmental impact, and the possibility of using powder coatings on highly sensitive materials, such as wood [36] or the magnesium alloy of the AZ series, which lose their mechanical properties at elevated temperatures [37][38][39].…”

“…In this work, the possibility of using a UV-cured powder coating on AZ91 magnesium alloy was examined. The synthesis method and physicochemical properties of the acrylic resin used were optimized and investigated in our previous work [35]. To ensure proper adhesion of the organic coating to the magnesium substrate, a conversion coating was created on its surface.…”