Aqueous Epoxide Ring-Opening Polymerization (AEROP): Green Synthesis of Polyglycidol with Ultralow Branching

A green synthesis method for the preparation of polyglycidol in buffer with a high degree of control is presented. Polymerizations were conducted in phosphate buffered saline (PBS) of varying pH 3.8, 6.0, and 8.0 and deionized water at temperatures of 60, 80, and 100 degrees C. Taking advantage of the catalytic reactivity between water and glycidol afforded a novel green polymerization technique for the facile synthesis of polyglycidol systems with semibranched architectures with a degree of branching (DB) of 0.24, which situates the polymers between purely linear (DB = 0) and hyperbranched (DB = 0.56-0.63) systems. This method sidesteps the strenuous polymerization conditions required for most polyglycidol structures and provides well-controlled and reproducible species with a high degree of linearity and narrow polydispersities of 1.1-1.2 via the first green and nonexothermic synthesis of polyglycidol.