polyoxyalkylene

Polyoxyalkylene refers to a class of polymers characterized by repeating oxyalkylene units. These units are typically derived from epoxides such as ethylene oxide or propylene oxide, linked together by ether bonds. The general structure can be represented as -(CH2-CH(R)-O)-, where R can be hydrogen or an alkyl group. The most common types are polyethylene glycol (PEG), where R is hydrogen, and polypropylene glycol (PPG), where R is a methyl group. Copolymers containing both ethylene oxide and propylene oxide units are also prevalent.

These polymers are synthesized through ring-opening polymerization of epoxides, usually initiated by a nucleophile like water or an alcohol in the presence of a catalyst. The properties of polyoxyalkylenes are highly dependent on the length of the polymer chain and the type of alkylene unit. For example, lower molecular weight PEGs are liquids, while higher molecular weight PEGs are waxy solids. The presence of ethylene oxide units generally imparts hydrophilicity, while propylene oxide units increase hydrophobicity.

Polyoxyalkylenes find widespread use in various industries due to their versatile properties. They function as surfactants, emulsifiers, lubricants, and dispersants. In the pharmaceutical industry, they are employed as excipients, solubilizers, and drug delivery vehicles. Their biocompatibility and tunable properties make them suitable for medical applications. They are also used in cosmetics, food products, and as components in polyurethane foams and resins.