UV LED curable epoxy soybean-oil-based waterborne PUA resin for wood coatings
Xiu Li, Di Wang, Longying Zhao, Xingzhou Hou, Li Liu, Bin Feng, Mengxin Li, Pai Zheng, Xuan Zhao, Shuangying Wei
Abstract
An environmentally friendly waterborne wood coating with a rapid curing speed and good mechanical properties was investigated. Acrylated epoxidized soybean oil (AESO) and pentaerythritol triacrylate (PETA) were introduced to a UV-curable waterborne polyurethane acrylate (PUA) resin, which realize the fast curing of the coating under a 395-nm UV LED light source. The emulsion and film were characterized by particle size, FTIR, 1H-NMR and the mechanical properties. The result showed that the mechanical properties of the film were optimal with AESO content 45%, which tensile strength, elongation at break and modulus of elasticity were 27.53 MPa, 26.35%, and 293.62 MPa, respectively. The particle size of the emulsion was smaller than 50 nm. It displayed a good stability and a uniform distribution. The glass transition temperature was 123.3 °C. The hardness, the adhesion force, the water absorption rate, the gloss and the abrasion loss were 6H, Level 1, 9.9%, 22.1°, and 0.002 g, respectively. After pre-drying and UV LED irradiation, the wood coating cured quickly in a short time. The epoxy soybean-oil-based waterborne PUA resin indicated highly promising in the field of wood coatings.