Dipropylene glycol is a clear, colourless, slightly viscous liquid which is far less hygroscopic than other common glycols. It is an excellent solvent completely miscible with water and many organic compounds such as ethanol, benzene, toluene, castor oil, carbon tetrachloride, monoethanolamine and diethanolamine. Dipropylene glycol is also an excellent mutual solvent or cosolvent.
Dipropylene glycol is an excellent solvent for inks, especially the steam-set type, and for those used in printing food packages where the absence of residual taste and odour is essential. A mixture of dipropylene glycol and diethylene glycol is used as an extraction solvent for separating high purity aromatics from hydrocarbons. The polyester resins prepared from dipropylene glycol tend to be more flexible and less crystalline than those prepared from ethylene glycol. Dipropylene glycol polyesters are not so sensitive to water as the diethylene glycol polyesters.
Dipropylene glycol has been used as a heat transfer fluid for both low and high temperature applications. It can be used as a high temperature reaction medium in the synthesis of certain pharmaceuticals.
Storage: Dipropylene glycol is noncorrosive. It has a low vapor pressure and high flash point.