Functional Polycarbonate of a D-Glucal-Derived Bicyclic Carbonate via Organocatalytic Ring-Opening Polymerization

Herein, we demonstrate the synthesis of a bicyclic carbonate monomer of a D-glucal derivative, which originated from the natural product D-glucose, in an efficient three-step procedure and its ring-opening polymerization (ROP), initiated by 4-methylbenzyl alcohol, via organocatalysis. The ROP behavior was studied as a function of time, catalyst type, and catalyst concentration by using size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR) spectroscopy. Using a cocatalyst system of 1,8-diazabicyclo[5.4.0]undec-7-ene and 1-(3,5-bis(trifluoromethyl)phenyl)-3-cyclohexyl-2-thiourea (S mol %) afforded poly(D-glucal-carbonate) (PGCC) with almost complete monomer conversion (ca. 99%) within 1 min, as analyzed by H-1 NMR spectroscopy, and a monomodal SEC trace with dispersity of 1.13. The resulting PGCCs exhibited amorphous characteristics with a relatively high glass transition temperature at ca. 69 degrees C and onset decomposition temperature at ca. 190 degrees C, as analyzed by differential scanning calorimetry and thermogravimetric analysis, respectively. This new type of potentially degradable polymer system represents a reactive functional polymer architecture.