Synthesis and properties of UV-curable cardanol-based acrylate oligomers with cyclotriphosphazene core

Multiarm cardanol-based oligomers with a cyclotriphosphazene core were prepared through a nucleophilic substitution reaction; the structures of oligomers were fully characterized and confirmed through Fourier transfer infrared spectrometry, 1H nuclear magnetic resonance (NMR), 31P NMR, and gel permeation chromatography. The designed multiarm bio-based acrylates (AECC) were successfully prepared by epoxidizing the unsaturated aliphatic chain of cardanol segments with m-chloroperoxybenzoic acid and acrylating epoxy groups. The synthesized oligomers contain rigid phosphazene/benzene rings as “hard cores” and long aliphatic chains as “flexible shells.” Compared with commercial hyperbranched polyurethane acrylate (CN2302) and acrylated epoxidized soybean oil, cured AECC coatings and films exhibited not only greater hardness, excellent adhesion, higher glass transition temperatures, and excellent mechanical properties but also good thermal stability and biodegradability. We successfully obtained a high-performance UV-curing resin that has a high biorenewable material content and can meet basic daily requirements.