Polypropylene glycol or polypropylene oxide is the 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. In 2003, 60% of the annual production of propylene oxide of 6.6×106 tonnes was converted into the polymer.
PPG 1000D is recommended in manufacturing of filled and unfilled elastomers, sealants, adhesives and encapsulation compounds.
PPG 1000D is also used in prepolymers, high resilience foam and coatings.