UV-curable coating prepared from castor oil
Due to the complex chemical modification, harsh synthesis conditions and imperative post-treatment, the industrial products of vegetable oil-based polymers are very rare. In a new study, castor oil-based polyurethane acrylic resin (COPUA) was synthesised by one-pot method from castor oil (CO), isophorone diisocyanate (IPDI), hydroxyethyl acrylate (HEA) and isobbornyl acrylate (IBOA).
Various UV curable films were prepared by mixing non-treated COPUA, photoinitiator (PI-1173), mono-functional active diluent hydroxyethyl methacrylate (HEMA) or bifunctional active diluent tripropylene glycol diacrylate (TPGDA). The mechanical performances of the cured films were studied. Besides, DMA and TGA analyses were used to determine the dynamic thermodynamic performances and the thermal stability of the cured films.
Environmentally friendly strategy
As a result, the pure COPUA cured film exhibited excellent thermal stability, storage modulus (421 MPa at 25 °C), tensile strength (9.87 MPa) and high glass transition temperature (60.3 °C). The cross-linking density of films improved with increasing the content of active diluent, resulting in excellent overall performances. In addition, all films possessed excellent hardness, adhesion, solvent resistance and flexibility. According to the researchers, the study provides a green and environmentally friendly strategy for the synthesis of vegetable oil-based polymers, reducing the chemical dependence on petrochemical energy.
The study has been published in Progress in Organic Coatings, Volume 159, October 2021.