Polyglycols

Polyglycols are a class of synthetic polymers that are essentially repeating units of ethylene oxide or propylene oxide. The simplest form is polyethylene glycol (PEG), also known as macrogol, and polypropylene glycol (PPG). These polymers are characterized by the presence of ether linkages in their backbone. The general formula for a polyglycol can be represented as HO-(R-O)n-H, where R is typically an ethylene (CH2CH2) or propylene (CH2CH(CH3)) group, and n is the degree of polymerization, indicating the number of repeating units.

Polyglycols exist in a wide range of molecular weights, from low molecular weight liquids to high molecular weight solids. Their physical properties, such as viscosity, solubility, and melting point, are heavily dependent on this molecular weight and the specific repeating unit. They are generally water-soluble and exhibit good solvency for many organic compounds.

Due to their versatile properties, polyglycols find numerous applications across various industries. They are used as humectants in cosmetics and pharmaceuticals, as lubricants in industrial processes, and as surfactants and emulsifiers in detergents and personal care products. In the pharmaceutical industry, PEGylation, the process of attaching PEG to a protein or peptide, is employed to improve drug stability, solubility, and bioavailability, and to reduce immunogenicity. Polyglycols also serve as intermediates in the synthesis of other chemicals and are used in the production of polyurethane foams.