Polyethylene glycol (PEG), also known as polyethylene glycol ether, is prepared by gradual addition reaction of ethylene oxide and water or ethylene glycol, and its raw material is mainly from petroleum products. With the increase of polymerization degree, the physical appearance and properties of polyethylene glycol gradually changed. When changing from colorless and odorless viscous liquid to waxy solid, its hygroscopic capacity decreases accordingly. It has the chemical properties of alcohol and can react with fatty acids to form esters. Soluble in water, ethanol and various organic solvents. It is stable to heat, acid and alkali, and has no effect on many chemicals. It has good hygroscopicity, adhesion and lubricity. It is non-toxic and non-irritating.
It has strong water absorption, can absorb water from the air under normal temperature, and the liquid can be mixed with water in any proportion. When the temperature rises, the solid polyethylene glycol of any fraction can be miscible with water in any proportion. When the temperature reaches the boiling point of water, the polymer will precipitate, and the precipitation temperature depends on the molecular weight and concentration of the polymer.
It is a non-ionic polymer, which is stable under normal conditions. It can oxidize with oxygen in the air at 120 ℃ or higher. It is protected by inert gases such as carbon dioxide or nitrogen, and does not change at 200~240 ℃. When it rises to about 300 ℃, the molecular chain segment breaks and degrades.