Facile Synthesis of Cardanol-Based Reactive Diluents and Application for Anti-Shrinkage UV-curable Resins

Biomass resources possessed the advantages of being natural, renewable, abundant, inexpensive, and easy to degrade. Therefore, fabricated bio-based UV-curable materials have gradually attracted much more attention, which meet the requirements of sustainable development and save petrochemical resources. In this paper, cardanol was modified to synthesize radical reactive diluent and hybrid reactive diluent by a facial method and was used to adjust the viscosity and reduce the volume shrinkage of UV-curable epoxy acrylic resin. The structure-activity properties and UV-curing kinetics of the obtained UV-curable materials were clarified, and the anti-shrinkage mechanism was also explored. In addition, the obtained cardanol-based materials were compared with petroleum based diluent methyl methacrylate (MMA) and application for UV-curable coatings. The volume shrinkage of the cardanol-based reactive diluents was 3.5% and 2.1%, respectively, which were lower than MMA (4.6%). The C(sic)C conversion of the cardanol-based reactive diluent exhibited the highest value of 79.6%. This work provided a specific theoretical basis for the subsequent design and application of bio-based UV-curable resins. It is of certain significance to the alleviation of the shortage of petrochemical resources and the sustainable development of the UV-curable coating industries.