Polyethylene glycols are polymers of ethylene oxide with the generalised formula HO-(CH2-CH2-O)n-H, with Œn¹ indicating the average number of oxyethylene groups.
In chemical abstracts polyethylene glycols are described under the scientific name Poly(oxy-1,2-ethanediyl)-a-hydro-w-hydroxy in combination with the CAS register number 25322-68-3. In the European Pharmacopoeia the name ³Macrogol² is found for PEG.
Polyethylene glycols are available in average molecular weights ranging from 200 to 8000. All PEGs are designated by a number indicating the average molecular weight. PEG 200, 300 and 400 are clear viscous liquids at room temperature but PEG 600 and 1000 require a temperature above 40°C. PEG 1500, 3350, 4000, 6000 and 8000 are white waxy solids that are supplied in flake form. Some grades may also be supplied in molten form. For special product demands, information on applications or other special requirements contact the local sales office.
All PEGs are soluble in many polar solvents as aliphatic ketones, alcohols, glycol ethers, esters and aromatic hydrocarbons. PEGs are readily miscible with water, the solid PEGs are slightly less soluble in water with their solubility decreasing as molecular weight increases.