Modified castor oil-based UV/thermal dual-curing polyurethane acrylate coatings with outstanding comprehensive properties

Due to the fact that single UV-cured coatings frequently fail to fulfill the requirements in terms of depth and chroma, and do not reach the ideal state in terms of comprehensive performance. In order to solve these painpoints more effectively, the sulfhydryl-modified castor oil (COME) was successfully synthesized by introducing beta-mercaptoethanol onto the plant-based material castor oil (CO) through the thiol-ene clink reaction. Subsequently, the synthesized polyurethane acrylate prepolymer (COPUA), monomer, photoinitiator and thermocuring agent were used as A component, and COME was used as B component. The two were mixed evenly according to a certain proportion, and the modified castor oil based polyurethane acrylate (COMEPUA) coatings were fabricated by UV/thermal dual-curing technology. Based on a series of performance test outcomes, the coating demonstrates excellent comprehensive properties, encompassing mechanical properties (where the shear strength, tensile strength, elongation at break, and hardness can respectively reach 5.26 MPa, 9.92 MPa, 132.55 %, and 47.77 Shore D), coating properties (where the absorption rates after 72 h immersion in water, ethanol, 10 wt% HCl, and 10 wt% NaOH solvents are respectively 0.66, 17.98, 1.89, and 0.71 %, and the volume resistivity and breakdown voltage are respectively 1.74x1016 Omega & sdot;cm and 10 KV) and curing properties (where the curing depth can reach 9.82 mm, which is significantly higher than 3.51 mm of single UV curing, and the colored curing is complete). It can exert protective functions such as anti-corrosion, anti-fouling, and insulation on circuit boards, electronic packaging, and device surfaces, and holds great potential in the application of coating materials.