Polyethylene-glycol

What polyethylene glycol (PEG) are

Polyethylene glycols are polymers of ethylene oxide with hydroxyl groups at both ends. They are described by average molecular weight: PEG 200, 300, 400 and 600 are liquids; PEG 1000, 1500, 2000, 4000, 6000 and 8000 are waxy solids. Macrogol is the name used for the same polyethylene glycol at that average molecular weight, so PEG 400 and Macrogol 400 are one grade. Dyna Glycols manufactures PEG for use as solvents, humectants, ointment bases, tablet binders, plasticisers, mould-release aids and chemical intermediates.

PEG is not a surfactant in the same way as a fatty alcohol ethoxylate, but it is produced on related alkoxylation technology and is used alongside ethoxylates in many formulae. Low molecular weights mix with water and many polar organics. High molecular weights give body, lubrication and a defined melting range that pharmaceutical and cosmetic chemists rely on.

How Dyna Glycols manufactures polyethylene glycol (PEG)

Ethylene oxide is polymerised to the target average molecular weight under controlled conditions. Release tests typically include appearance, viscosity or melting range, hydroxyl value, pH of aqueous solution, water, colour and, where specified, sulphated ash. Stainless-steel equipment and 24/7 QA support both industrial and higher-documentation grades.

Customers who need a narrow molecular-weight window, a low aldehyde or a particular pharmacopoeia-style test list should attach that list to the enquiry. Industrial PEG and more tightly specified PEG are both in the manufacturing scope.

Typical grades in this range

The molecular weights below are the usual catalogue points. PEG 200, 400, 600, 1500, 4000, 6000 and 8000 each have a page under both the PEG and Macrogol names. Intermediate weights are available.

• Liquid PEG / Macrogol: 200, 300, 400, 600
• Solid PEG / Macrogol: 1000, 1500, 2000, 4000, 6000, 8000

Related pages: PEG 200 / Macrogol 200, PEG 400 / Macrogol 400, PEG 600 / Macrogol 600, PEG 1500 / Macrogol 1500, PEG 4000 / Macrogol 4000, PEG 6000 / Macrogol 6000, PEG 8000 / Macrogol 8000.

Where polyethylene glycol (PEG) are used

Pharmaceuticals and personal care use PEG 400 as a solvent and PEG 1500–4000 as ointment and cream bases or tablet binders. Detergents and cleaners use liquid PEG as a solvent and hydrotrope partner. Inks, dyes and textile pastes use PEG for hygroscopicity and as a humectant.

Rubber, plastics and moulding use higher PEG grades as lubricants and release agents. Electroplating, metal treatment and gas treatment formulations use PEG as a soluble polymer carrier. PEG is also the starting point for PEG esters manufactured in the Esters family.

Laboratory and industrial formulations that need a water-soluble, low-volatility polyether with two hydroxyls specify PEG by molecular weight rather than by a surfactant HLB.

How to specify polyethylene glycol (PEG)

State the molecular weight (or a viscosity / melting-range target), the required pharmacopoeia or industrial test list, and colour or odour limits. Say whether the grade will be esterified later, because residual catalyst and water then matter more.

For ointment and tablet use, include the melting behaviour and any limit on ethylene glycol or diethylene glycol if those tests are part of the customer specification.

Quality, documents and supply

Each PEG lot is released against the agreed molecular-weight identity tests and the impurity list on the TDS. SDS and COA are issued after company verification. Samples allow melting, solubility and compatibility checks.

Liquid PEG is packed in drums or IBCs; solid PEG in bags or drums according to form. Keep solids dry. Warm liquids only as needed and avoid copper that can discolour some lots.

Practical notes on polyethylene glycol (PEG)

Hydroxyl value falls as molecular weight rises. It is the practical identity test on the COA together with viscosity (liquids) or melting range (solids).

PEG 400 is fully water miscible and a common solvent for actives that do not dissolve in water or ethanol alone. PEG 4000 and 6000 dissolve more slowly and are used for body and binding rather than as solvents.

Hygroscopicity is high for low molecular weights. Closed containers and dry handling protect both assay and flow of solid grades.

PEG can form complexes with some actives and can affect the melting of fatty bases. Compatibility trials should use the same molecular weight that will be purchased.

Dyna Glycols also manufactures PEG esters. If the need is an emulsifier rather than a polyether solvent, the PEG ester or fatty acid ethoxylate pages are the better starting point.

Do not confuse PEG with PPG (polypropylene glycol) or with a fatty alcohol ethoxylate of similar viscosity. The COA should show a polyethylene glycol identity, not a surfactant hydrophobe.

Ordering and evaluating polyethylene glycol (PEG)

Send the application, the analytical window and the pack size when you request a laboratory sample of polyethylene glycol (PEG). SDS, TDS and COA follow a short company check. Handle and store the grade as the SDS describes.