PNP - Propylene Glycol Monopropyl Ether

About This Product

Propylene glycol n-propyl ether, PnP, has the formula C6H14O2 and CAS number 1569-01-3. It is a clear colourless liquid that remains fully miscible with water while dissolving oils, greases and many resins, and it sits between PE and PnB on the propylene-series ladder. Coupling is the function it is bought for. A water-based cleaner has to attack oily soil, but oil and water do not mix, and a surfactant alone leaves the soil dispersed rather than dissolved. A coupling solvent bridges the two: the propyl end associates with the oil and the hydroxyl end with the water, so the soil is taken into solution and carried away in the aqueous phase rather than re-depositing. PnP is effective at this because it holds both properties strongly rather than trading one against the other, which the shorter ethers do not manage and the longer butyl ethers achieve only with reduced water tolerance. It is also used as a coalescent in latex systems, where it temporarily softens polymer particles so they fuse into a continuous film. It is used in water-based cleaners and degreasers, latex paints as a coalescent, coatings and inks, and in metal cleaning. Bio Green Chem supplies PnP to specification on assay, alpha isomer content, water, acidity, colour and residue.