Polyurethanes Derived From Coal Extract

Subbituminous coal from the powder river basin was extracted with N,N-dimethylformamide at atmospheric pressure to yield a solid extract that provided phenolic and carboxylic acid groups. The coal extract was employed as polyol in polyurethane (PU) synthesis. A solvent-free synthesis using 2,4-toluene diisocyanate (TDI) resulted in a porous PU solid. Reaction with TDI in solution resulted in a soluble PU that could be applied as adhesive or coating. Coatings were also prepared from coal extract solutions and commercial, polymeric isocyanates, providing excellent adhesion to aluminum. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48776.