Poly-G 20-56 Polyol Arch Chemicals Polyurethane (PU) - Polyols Arch low molecular weight polyols, in either solvent- or water-based formulations, have been a mainstay of the paint and coatings industry. Higher molecular weight polyols, like Poly-G® 20-28 and 85-29, are used for two-part, very high solid roof and deck coatings. high quality and reproducibility Diol. Used in the paint and coatings industry. Offers high quality and reproducibility.