Synthesis and properties of phosphorus-containing cardanol-based acrylates for flame-retardant UV/EB-cured coatings

In this article, two kinds of phosphorus-containing cardanol-based acrylates were designed and synthesized. Firstly, a pre-polymer (PT-HCE) with three arms was synthesized using hydroxyethyl cardanol ether (HCE) and phosphorus oxychloride (POCl3) as raw materials. Then, the PT-HCE was acrylated to synthesize phosphate tris-hydroxyethyl cardanol epoxy acrylate resin (AEPT-HCE) and phosphate tris-hydroxyethyl cardanol photosensitive resin (APT-HCE). The structures of PT-HCE, AEPT-HCE and APT-HCE were characterized and the results showed that the photosensitive resins were successfully synthesized. In addition, AEPT-HCE and APT-HCE were used to prepare the flame-retardant UV/EB curing coatings. The properties of the coatings were tested, and the results revealed that different structures have a certain effect on Tg and tensile properties of the coatings. The cured films demonstrated excellent flame-retardant properties, showing flammability rating of V-0 in UL-94 test.