Macrogol is the same polyethylene glycol
Polyethylene-glycol is a polyether diol. Buyers name it by average molecular weight, not by a single molecule. Macrogol is the name used for that same polyethylene glycol, so PEG 400 and Macrogol 400 are one grade, and PEG 4000 and Macrogol 4000 are one grade. The number is approximate. A lot is a distribution around that average, which is why hydroxyl value, viscosity or melting range, colour and water belong on the purchase specification.
Hydroxyl value falls as molecular weight rises. It is the practical identity test together with viscosity for the liquids and melting range for the solids. A liquid PEG will not give the melt or binding of a waxy grade, and a waxy grade will not pour like a solvent. Name the molecular weight on the enquiry so a neighbouring grade is not offered against the wrong window.
Liquid grades: PEG 200, 400 and 600
PEG 200 / Macrogol 200, also specified as Macrogol 200, is a clear liquid. It is the lowest molecular weight in this set, so it has the highest hydroxyl value and the strongest solvent and humectant character. Formulators use it as a polar solvent, a humectant and a chemical intermediate when PEG 400 would be too viscous. It is a polyethylene glycol diol, not a fatty alcohol ethoxylate of similar viscosity.
PEG 400 / Macrogol 400, also specified as Macrogol 400, is the usual water-miscible liquid when a buyer asks for a polyether solvent. It is used as a solvent for actives, a humectant, a carrier in cleaners and a feedstock when the same plant later makes a PEG ester. It is thicker than PEG 200 and still a liquid.
PEG 600 / Macrogol 600, also specified as Macrogol 600, is a viscous liquid between PEG 400 and the waxy solids. It is the humectant solvent and intermediate when a thin PEG 400 cut is not viscous enough, without the melt behaviour of PEG 1500. Specify viscosity or hydroxyl value so a PEG 400 lot is not supplied against a PEG 600 window.
Waxy grades: PEG 1500, 4000, 6000 and 8000
PEG 1500 / Macrogol 1500, also specified as Macrogol 1500, is a soft waxy solid. It is chosen for ointment and cream bases that must melt more readily than PEG 4000, and as a soft binder. Order it by melting range and hydroxyl value, not by a liquid viscosity.
PEG 4000 / Macrogol 4000, also specified as Macrogol 4000, is the usual solid polyethylene glycol for binding and body. It is used as a tablet binder, an ointment base, a plasticiser and a mould-release aid. It dissolves in water more slowly than PEG 400.
PEG 6000 / Macrogol 6000, also specified as Macrogol 6000, is a hard waxy solid specified when the melt must sit above PEG 4000 and the hydroxyl value must be lower. Typical duties are tablet binding, lubrication and release in plastics and rubber processing. It is still water soluble, and it dissolves more slowly than PEG 4000.
PEG 8000 / Macrogol 8000, also specified as Macrogol 8000, is the highest molecular weight in this set, with the lowest hydroxyl value and the least solvent character. It is used as a lubricant, plasticiser and mould-release aid when PEG 6000 is too low in molecular weight. Name PEG 8000 or Macrogol 8000 on the enquiry so a PEG 6000 lot is not offered against this window.
What to send with the enquiry
Name PEG or Macrogol and the molecular weight, the hydroxyl window, colour and water, and either viscosity for a liquid or melting range for a solid. Say whether the grade will be esterified later, because residual water then matters. Intermediate molecular weights can be quoted when a catalogue point is close but not exact. The map of the range is on the polyethylene glycol page.
An industrial PEG lot is not automatically a pharmacopoeia or food pack. If the receiving laboratory will run a Macrogol monograph, or will test residual ethylene oxide, 1,4-dioxane, ethylene glycol or diethylene glycol, attach that list at the enquiry. Dyna Glycols will not invent USP, EP or IP status for a lot that was not released that way.
Request a laboratory sample together with the current SDS and TDS. The certificate of analysis follows the shipping lot after manufacture at Kandla SEZ. Liquid grades are packed in drums or IBCs. Solid grades are packed in bags or drums and should be kept dry.