Polyethylene glycol ，PEG
Chemical properties:
The properties vary according to the relative molecular weight, ranging from colorless and odorless viscous liquids to waxy solids. The hygroscopicity decreases with the increase of molecular weight. This product is soluble in water, ethanol and many other organic solvents. Low vapor pressure, stable to heat, acid and alkali. It doesn't work with many chemicals. It has good hygroscopicity, lubricity and adhesion. Non-toxic, no stimulation.
Polyethylene glycol (PEG) is very stable under normal conditions, but it can interact with oxygen in the air at 120 C or higher. With the increase of molecular weight, the water solubility, vapor pressure, water absorption and solubility of organic solvents decrease, while the solidification point, relative density, flash point and viscosity increase accordingly. It has no effect on thermal stability, and does not hydrolyze with many chemicals.
Main uses
Polyethylene glycol (PEG) is widely used in cosmetic and pharmaceutical industries. Because polyethylene glycol has many excellent properties: water-solubility, non-volatility, physiological inertia, mildness, lubricity and make the skin moist, soft, have a pleasant aftereffect. Polyethylene glycol (Mr<2000) with relatively low molecular weight is suitable for wetting agents and consistency regulators. It is used in cream, lotion, toothpaste and shaving cream. It also applies to hair products that are not washed, giving hair a filamentous luster. Polyethylene glycol (Mr>2000) with relatively high molecular weight is suitable for lipstick, deodorant stick, soap, shaving soap, foundation and cosmetics. In detergents, polyethylene glycol is also used as suspension agent and thickener. In the pharmaceutical industry, it is used as the matrix of ointment, emulsion, ointment, lotion and suppository. Polyethylene glycol (such as Polyethylene Glycol NF, Dow Chemical Co.) marketed for food and drug use is more suitable for cosmetics. The application of methoxy polyethylene glycol and polypropylene glycol is similar to that of polyethylene glycol.
Polyethylene glycol (PEG) is widely used in many pharmaceutical preparations, such as injections, topical preparations, ophthalmic preparations, oral and rectal preparations. Solid grade polyethylene glycol can be added to liquid polyethylene glycol to adjust the viscosity of ointment for local use; polyethylene glycol mixture can be used as suppository matrix; polyethylene glycol aqueous solution can be used as suspension AIDS or to adjust the viscosity of other suspension media; polyethylene glycol and other emulsifiers can be combined to increase the stability of the emulsion. In addition, polyethylene glycol is also used as film coating agent, tablet lubricant, controlled-release materials, etc.
