DPNP - Dipropylene Glycol Monopropyl Ether

About This Product

Dipropylene glycol n-propyl ether, DPnP, has CAS number 29911-27-1 and is built on a two-unit propylene glycol backbone carrying a propyl ether group. It is a clear colourless liquid with good water miscibility and a high boiling point, supplied as an isomer mixture. Coalescence is its principal function, and the timing requirement explains the structure. A latex paint dries by the water leaving and the polymer particles pressing together and fusing into a continuous film. Below the polymer's film-forming temperature the particles are too hard to fuse and the coating cracks or powders. A coalescent works by temporarily dissolving into and softening those particles so they deform and knit together, then evaporating away, leaving a harder film than it entered. The timing has to be right: leave too early and fusion is incomplete, stay too long and the film remains soft and picks up dirt. The two-unit backbone gives DPnP a boiling point high enough to remain through the fusion stage, while the propyl group gives it enough affinity for the polymer to enter the particle at all. It is used as a coalescent in latex and water-based coatings, in industrial cleaners, printing inks and as a coupling solvent. Bio Green Chem supplies DPnP to specification on assay, water, acidity, colour, residue and isomer distribution.