An amorphous polyurethane exhibiting colorless transparency and efficient yellow emission

Abstract A polyurethane soluble in organic solvents was synthesized via polyaddition of dicyclohexylmethane-4,4′-diisocyanate with a newly designed diol monomer containing 2-(3,5-dialkynyl-2-hydroxyphenyl)-5-tert-pentylbenzoxazole as an excited-state intramolecular proton transfer (ESIPT) luminophore. The resulting polyurethane is amorphous with a high glass transition temperature of 164 °C. Spin-coated thin films were colorless and transparent and exhibited efficient yellow emission with a fluo