▎ 摘　　要

NOVELTY - Preparing bio-based polyurethane with dual photothermal repair functions involves adding isocyanate, organotin catalyst, and organic solvent to the dehydrated bifunctional polyol, and reacting at 75-85 degrees C for 2 hours to obtain a viscous isocyanate-terminated polyurethane prepolymer PU- 1, dissolving a small molecule chain extender containing disulfide bonds in an organic solvent and adding to the PU-1. The system reacts at 35-45 degrees C for one hour to extend the chain to obtain a viscous disulfide bond isocyanate-terminated polyurethane PU-2. The coumarin derivative monomer is dissolved in an organic solvent and added to the PU-2. The system reacts at 35-45 degrees C for one hour for end-capping to obtain a viscous disulfide-containing product PU-3, and polyurethane prepolymer end-capped by a coumarin derivative monomer. USE - Method for preparing bio-based polyurethane with dual photothermal repair functions used as packaging materials, coatings, elastomers. ADVANTAGE - The method improves self-repair performance and mechanical properties, preparation process is simple and environment friendly, and repair effect is obvious and efficient. DETAILED DESCRIPTION - Preparing bio-based polyurethane with dual photothermal repair functions involves adding isocyanate, organotin catalyst, and organic solvent to the dehydrated bifunctional polyol, and reacting at 75-85 degrees C for 2 hours to obtain a viscous isocyanate-terminated polyurethane prepolymer PU- 1, dissolving a small molecule chain extender containing disulfide bonds in an organic solvent and adding to the PU-1. The system reacts at 35-45 degrees C for one hour to extend the chain to obtain a viscous disulfide bond isocyanate-terminated polyurethane PU-2. The coumarin derivative monomer is dissolved in an organic solvent and added to the PU-2. The system reacts at 35-45 degrees C for one hour for end-capping to obtain a viscous disulfide-containing product PU-3, and polyurethane prepolymer end-capped by a coumarin derivative monomer. The carbon-based nano-scale material is dispersed with absolute ethanol and sonicated for 30-60 minutes after hydroxyl modification, added to the PU-3 and the system is stirred at 35-45 degrees C for 20-30 minutes and viscous carbon-containing material and disulfide bond coumarin derivative monomer-terminated polyurethane PU-4 is obtained. The viscous carbon-containing material and disulfide bond coumarin derivative monomer-terminated polyurethane PU-4 are poured into the mold and cured at 80 degrees C for 48 hours to obtain a bio-based polyurethane with dual repair functions material.