| abstract |
The present invention relates to polyester polyols made from aromatic polyacid sources, such as thermoplastic polyesters. the polyols may be made by heating a thermoplastic polyester, such as virgin polyethylene terephthalate, recycled polyethylene terephthalate or mixtures thereof, with a glycol to provide a digested intermediate which is then reacted with a digestible polymer which may be obtained from various streams of recycling waste. polyester polyols comprise a glycol digested polyacid source and an additional digestible polymer. Polyester polyols provide a sustainable alternative to biochemical or petrochemical based polyols. |