Towards the Sustainable Production of Higher-Molecular-Weight Polyglycerol

The step-growth polymerization of glycerol to relatively high molecular weight polyglycerol is investigated. Glycerol is a renewable material that can be derived from the transesterification of vegetable oils to biodiesel. Several soluble catalysts and their reaction mechanisms are compared and their effect on polymer molecular weight and microstructure is measured. High-molecular-weight PG with multimodal molecular weight distributions is observed using GPC, and partial branching is identified using (13)C NMR spectroscopy. Theoretical models are used to predict the gel point and to calculate monomer functionality.