What is propylene glycol?
When it comes to propylene glycol we can't fail to ask what is it. Propylene glycol, also known as propane-1,2-diol, is a synthetic liquid with the chemical formula C3H8O2. Normally it is a colorless creamy liquid, almost odorless but slightly sweet.
But, what is this synthetic organic compound made from? Propylene glycol can be made from hydration of propylene oxide, and it is mainly used to produce polymers.
What is propylene glycol used for?
45% of propylene glycol is used as chemical feedstock to produce unsaturated polyester resins. It's also closely related to our lives. Then how is propylene glycol used in daily life? Propylene glycol is found in many kinds of food products. As the food additive E1520, propylene glycol can react with fatty acids to form propylene glycol fatty acid esters and can be mainly used as food emulsifier; and also as an excellent solvent for flavoring and coloring in food.
With good solubility with various fragrances, propylene glycol can be used as a solvent and softening agent for cosmetics and as a humectant (E1520) in food and tobacco products. As one of the major ingredients of the "e-liquid" used in electronic cigarettes, propylene glycol is often used to create the vapor; and in the pharmaceutical industry, it is commonly used in the manufacture of various types of ointment, softening agent and excipient, etc.
Propylene glycol can reduce the freezing point of water, so it can be used as an aircraft deicing agent. The mixture of water and propylene glycol will be dyed pink to indicate that it is relatively non-toxic and sold in the name of camper or marine antifreeze. Propylene glycol is often used as a substitute for ethylene glycol as a low toxic and environmentally friendly vehicle antifreeze. It can also be used in paint, pesticides, coatings and other industries.
What is propylene glycol made from?
The extraction process of propylene glycol belongs to the technical field of chemical separation. The process is characterized by the easy crystallization of inorganic salts, but the organic salts in the fermentation broth of propylene glycol are not easy to crystallize. Adding an appropriate amount of inorganic acid to the fermentation broth of propylene glycol, the organic acid salts in the fermentation broth are replaced by organic acids, and the corresponding inorganic acid salts are generated; the fermentation broth was concentrated so that the inorganic acid salt is crystallized and separated from the fermentation liquid; the concentrated fermentation broth becomes a mixture of propylene glycol, amber acid, lactic acid, ethylic acid, glycerol and 2,3-butanediol, and the mixture is vacuum distilled to obtain the products of each component.