Sub-Product

Polypropylene Glycol is the Linear and Di-functional Polymer of Propylene Glycol. Chemically it is a Polyether. The term Polypropylene Glycol or PPG is reserved for low to medium range molar mass Polymer when the nature of the End-Group, which is usually a Hydroxyl group, still matters. The term "Oxide" is used for high molar mass Polymer when end-groups no longer affect Polymer Properties. Polypropylene Glycol is produced by Ring-Opening Polymerization of Propylene Oxide. The Initiator is an Alcohol and the Catalyst a Base, usually Potassium Hydroxide. In order to form a Linear Diol (or Glycol) a Di-functional Initiator such as Ethylene Glycol, Propylene Glycol, or Water is used. Diols are typically used in Polyurethane Coatings, Adhesives, Elastomers, and Sealants (CASE) Applications.