| abstract |
The present invention relates to polyester polyols made from aromatic polyacid sources, for example, thermoplastic polyesters. The polyol can be made by providing a digested intermediate which is subsequently reacted with a digestible polymer by heating pure polyethylene terephthalate, regenerated polyethylene terephthalate, or a mixture thereof with glycol, which can be obtained from various regenerated waste streams . The polyester polyol comprises a glycol-digested polyacid source and an additional digestible polymer. The polyester polyols are a sustainable alternative to petrochemical or biochemical polyester polyols. |