Propylene glycol is an important raw material for unsaturated polyester, epoxy resin, and polyurethane resin. The consumption in this respect accounts for about 45% of the total consumption of propylene glycol. This unsaturated polyester is used in large quantities for surface coatings and reinforced plastics. Propylene glycol has good viscosity and hygroscopicity, and is non-toxic, so it is widely used as a hygroscopic agent, antifreeze agent, lubricant and solvent in the food, pharmaceutical and cosmetic industries.
In the food industry, propylene glycol and fatty acids react to form propylene glycol fatty acid esters, which are mainly used as food emulsifiers; propylene glycol is an excellent solvent for condiments and pigments. Propylene glycol is often used in the pharmaceutical industry as a solvent, softener and excipient for the manufacture of various ointments and ointments. Because propylene glycol has good mutual solubility with various fragrances, it is used as a carrier for various fragrances and as a cosmetic agent. Solvents and softeners, etc. Propylene glycol is also used as a tobacco moisturizing agent, a mildew inhibitor, a lubricant for food processing equipment, and a solvent for food marking inks. Aqueous solutions of propylene glycol are effective antifreeze agents.