Preparation and properties of rosin-based naphthalene fluorescent polyurethane

Fluorescent polyurethanes (FPU) have been widely used in coatings, temperature recognition, fluorescent probes, and other fields because of their diverse structures and properties. Unfortunately, most FPUs are currently produced from petroleum-based products. Herein, a thermoplastic rosin-based naphthalene FPU was prepared by using the biobased ester of acrylic rosin and glycidyl methacrylate, polycaprolactone, 1, 5-dihydroxy naphthalene (1, 5-DN) and isophorone diisocyanate as the raw materials. The structure of FPU was confirmed by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR). In addition, thermal performance analysis (TGA, DSC) and water contact angle analysis (WCA) showed that the addition of 1, 5-DN improved the thermal stability and hydrophobicity of FPU. More importantly, FPU exhibited good fluorescence performance in both liquid and solid states, and the fluorescence intensity increased with increasing temperature. Both aniline and trichloromethane showed effective fluorescence quenching for FPU. Therefore, FPU is a promising material for applications in temperature recognition and fluorescence probes.