Biomass Liquefaction and Alkoxylation: A Review of Structural Characterization Methods for Bio-based Polyols

The conversion of biomass via liquefaction and alkoxylation has been shown to be a versatile and promising route for producing bio-based polyols for polyurethane synthesis. Despite the complexity of bio-based polyols, this review showcases how detailed structural characterization of bio-based polyols is feasible to elucidate their structural attributes. Key polyol characteristics including polyol composition (classes of compounds, aromatic content, homopolymer content), alcohol type, and molecular structure (molecular weight and molecular weight distributions, polymer linkages) together with methods for identification of degradation products and side reactions, and analysis of residues are discussed. Finally, the challenges and outlook associated with structural identification of bio-based polyols are presented.