Cationic polymerization of cyclic trimethylene carbonate induced with initiator and catalyst in one molecule: Polymer structure, kinetics and DFT

Abstract

Trimethylene carbonate, the monomer that can be prepared from CO2 and 1,3-propanediol, was polymerized cationically, according to the activated monomer mechanism, as it follows from the polymerization kinetics and the DFT studies. Polymerization provides the biocompatible, degradable polymer and was conducted with initiator and catalyst in one molecule (CINICAT). This is in contrast to the known processes when protonic acids (organocatalysts) require addition of an independent initiator and then the low molar mass catalyst, left free in the polymer, may diffuse to its surface, changing the properties. The used CINICAT: hydroxymethylphosphonic acid {HOCH2P(=O)(OH)2} is quantitatively embedded in the polymer molecules. Polymerization is living/controlled and provides at 100 °C, in bulk, polymers with molar masses ∼104 g/mol. The acidic end groups were further used for polymer functionalization and in reaction with diepoxybutane were quantitatively converted into reactive epoxy groups.