Soybean Oil-Based UV-Curable Coatings with High Bio-renewable Content

Background: UV-curable coating materials with high biorenewable content performance comparable to petrochemical-based formulations and lower cost are highly desirable. Commercialized soybean oil (SBO) derivatives such as acrylated epoxidized soybean oil (ASBO) are important starting materials for the development of soy-based materials such as coatings adhesives plasticizers inks and lubricants. Combining monomers possessing higher acrylate functionality with ASBO is expected to produce UV-curable coatings with better crosslinking and thus greatly enhanced coating film properties. One promising monomer for this purpose is found in the growing field of hyperbranched polymers. Hyperbranced acrylates (HBAs) have been shown to be effective low-viscosity toughening agents for acrylate-based UV-curable coatings. Technology Description: Scientists working at NDSU have developed a UV-curable coating that is based on acrylated soybean oil and hyperbranched acrylates that shows excellent coating properties as well as superior anti-stain and anti-corrosion performance on metals. Applications: Polyester hyperbranched acrylates (HBAs) with differing backbone Tg values and acrylate functionalities were formulated into ASBO-based UV-curable coatings with THFA as a reactive diluent. The addition of HBAs greatly enhanced the coating hardness adhesion impact resistance tensile modulus and toughness and Tg. The change of coating performance after HBA addition was attributed to the structural features of the more hydrophilic higher Tg HBAs. In addition it was shown that thermal annealing of the UV-cured coating films further enhanced the soy-based coating film properties such as hardness adhesion and Tg as a result of further reaction of residual acrylate groups in the coating films. The results showed that UV-curable coatings of reasonably high biorenewable content with much improved coating performance can be obtained using synthetic HBAs as efficient toughening agents.