Technical Specifications
| Property | Unit | Typical Value | Test Method |
|---|---|---|---|
| Demulsibility | min | 5 | — |
| Flash point | °C | 235 | ASTM D93 |
| Density at 20°C | kg/m³ | 998 | ASTM D4052 |
| Water content | % | 0.01 | ASTM D95 |
| Solubility (Mineral Group I–III) | Slightly soluble | — | |
| Appearance | Light yellow transparent liquid | Visual |
* Typical values from batch production. Batch-specific COA available on request.
Technical content reviewed by the CheMost additives team · Specifications last reviewed
Molecular Structure
Molecular structure · EO/PO polyether demulsifier
HO–(C₂H₄O)ₐ–(C₃H₆O)ᵦ–H
Non-ionic EO/PO block polyether: hydrophilic polyoxyethylene (EO) and lipophilic polyoxypropylene (PO) blocks whose balance drives oil-water separation while remaining oil-soluble.
What Is a Polyether Demulsifier?
CheMost-D2 is an oil-soluble, non-ionic polyether demulsifier — a surfactant built from polyoxyethylene (EO) and polyoxypropylene (PO) units that enhances the separation of water from a lubricant and, at the same time, helps suppress foaming. It is supplied as a light-yellow transparent liquid (grade D2) and works at very low treat: an addition of about one part in ten thousand effectively improves an oil’s water-shedding capacity.
Its non-ionic EO/PO architecture is the classic demulsifier chemistry for industrial and marine oils: the hydrophilic EO blocks and lipophilic PO blocks are balanced so the molecule sits at the oil-water interface, breaks the emulsion and lets water coalesce and drop out, while staying fully oil-soluble. The TDS highlights it as particularly suitable for marine lubricating oil, and its high flash point (235°C) suits hot, long-life systems.
CheMost offers two complementary demulsifier chemistries: this non-ionic polyether D2, and the amine-based amine polyether demulsifier (D1) — see the comparison below.
How a Polyether Demulsifier Works
EO/PO interfacial balance
The molecule’s hydrophilic polyoxyethylene and lipophilic polyoxypropylene blocks give it a tuned affinity for both the oil and the water. It concentrates at the oil-water interface, displaces the species that stabilise an emulsion, and lowers the interfacial film strength so dispersed water droplets coalesce and separate.
Fast water separation at very low treat
Because the EO/PO surfactant is highly interface-active, only a tiny addition — on the order of 100 ppm — is needed to restore quick, clean water shedding, keeping the additive’s contribution to the oil’s other properties minimal.
Foam suppression
The same interfacial activity that breaks oil-water emulsions also helps destabilise foam, so D2 contributes some foam suppression alongside its demulsifying role — a useful secondary benefit, though not a replacement for a dedicated defoamer where heavy foaming is expected.
Oil-soluble, high flash
D2 is oil-soluble and blends at room temperature, and its high flash point (235°C) suits the hot, long-service marine and industrial oils it is designed for.
Polyether vs Amine Demulsifier
CheMost’s two demulsifier chemistries are chosen by what the oil needs:
| Property | Polyether (D2) | Amine polyether (D1) |
|---|---|---|
| Chemistry | Non-ionic EO/PO polyether | Amine + propylene oxide |
| Flash point | 235 °C | 130 °C |
| Nitrogen | None | 0.6% (adds antioxidancy) |
| Extra benefit | Helps suppress foam | Rust-inhibitor synergy, antioxidancy |
| Best suited to | Marine, turbine & hydraulic oils | Lube oils that contact water |
Choose D2 for marine oils and wherever foam suppression is wanted alongside water separation; choose the amine polyether D1 where water extractability, antioxidancy and synergy with succinic-acid rust inhibitors are the priority. Both are dosed at very low levels.
Applications
This non-ionic polyether demulsifier is used as the water-separation component in formulations targeting the categories below; the finished-oil water-handling and foam performance depend on the complete additive system.
Marine lubricating oils
The application the TDS specifically highlights: in marine oils that must handle water contamination, D2 promotes fast oil-water separation while helping keep foam under control.
Turbine oils
Steam and water ingress make demulsibility (ASTM D1401) a defining property of turbine oils; the EO/PO demulsifier restores fast water release in steam, gas and hydro turbine lubricants.
Hydraulic & circulating oils
Hydraulic and circulating systems take in water in service; D2 keeps the oil shedding it quickly so it can be drained, protecting the system and helping suppress foam in the reservoir.
Industrial oils needing water release
Any industrial oil that must release water cleanly — and benefit from some foam control — is a fit for the non-ionic polyether chemistry.
Finished-oil performance and any industry approvals belong to the fully formulated oil, not to an individual demulsifier component.
Treat Rate & Handling
Demulsifiers are low-dose, high-impact additives: the technical data sheet indicates an effective addition of about one part in ten thousand — roughly 100 ppm (≈0.01 wt%). They are dosed to the demulsibility result, not to a fixed percentage.
dose to the demulsibility target — more is not better
As with any demulsifier, avoid over-treating. The additive’s bulk solubility in mineral base oils is only slight (the Technical Specifications note it as slightly soluble in Group I–III), so although it dissolves readily and blends at room temperature at its low working level, putting in more than the oil needs exceeds that limit and causes turbidity (haze) — another reason to dose to the demulsibility result rather than higher. Because demulsibility is a whole-formulation property, the demulsifier is balanced against the polar additives that influence it.
The figures above are the TDS guideline and typical practice; the right level depends on the base oil and the rest of the additive system. CheMost can provide demulsibility optimisation support on request.
Formulating With a Polyether Demulsifier — Complementary Additives
Demulsibility and foam control are balanced across the whole additive system; D2 is matched with the related components:
Foam inhibitors & defoamers
D2 helps suppress foam, but where heavy or persistent foaming is expected a dedicated silicone or polyacrylate defoamer is added; the two interfacial additives are tuned together so neither undermines the other.
Rust & corrosion inhibitors
Polar rust inhibitors can hold water in the oil and reduce demulsibility; the demulsifier level is balanced against them so a water-exposed oil keeps both rust protection and fast water release.
Antioxidants
In the hot, long-life marine and turbine oils D2 serves, aminic and phenolic antioxidants carry the oxidation control that keeps the oil — and its demulsibility — stable over a long service life.
Amine polyether demulsifier (D1)
Where strong water extractability and synergy with succinic-acid rust inhibitors are needed instead, the amine-based D1 is the alternative demulsifier chemistry.
Documentation, Qualification & Regulatory Support
Standard documentation — Certificate of Analysis (COA, per shipment), Technical Data Sheet (TDS) and Safety Data Sheet (SDS, GHS/CLP) — is provided. The full TDS is available on request rather than as a public download. Additional support is available on request:
Regulatory documentation
REACH, TSCA and country-specific market-registration documentation support available on request.
Third-party inspection
SGS / Intertek / BV pre-shipment inspection can be arranged on request.
Custom grades & packaging
Custom grades and packaging on request.
Formulation support
Demulsibility optimisation and treat-rate guidance from our technical team.
Packaging & Supply
This polyether demulsifier is stocked and shipped worldwide, with a typical lead time of 1–15 days and a 36-month shelf life at ambient temperature (maximum storage 50°C; maximum blending temperature 70°C). Samples and quotations are answered within 12 hours.
Packaging
25 kg or 200 kg metal drum.
Minimum order
1 drum — no minimum order value.
Incoterms
FOB · CIF · EXW, to suit your freight arrangement.
Loading ports
All major Chinese ports.
Frequently Asked Questions
What is a polyether demulsifier used for?
It is an oil-soluble non-ionic surfactant that helps a lubricant separate from water, and it also helps suppress foam. The EO/PO polyether type (CheMost D2) is the classic demulsifier chemistry for marine, turbine, hydraulic and circulating oils that are exposed to water, and it works at very low treat rates.
How is the polyether (D2) demulsifier different from the amine (D1)?
D2 is a non-ionic EO/PO polyether with a high flash point (235°C) that also suppresses foam and is aimed at marine and industrial oils. D1 is an amine-plus-propylene-oxide chemistry with trace nitrogen, giving stronger water extractability, some antioxidancy and synergy with succinic-acid rust inhibitors. The full comparison is in the table above.
Does it also control foam?
Yes, to a degree — the same interfacial activity that breaks oil-water emulsions helps destabilise foam, so D2 contributes some foam suppression. For heavy or persistent foaming, pair it with a dedicated defoamer rather than relying on the demulsifier alone.
How much should I add?
Very little — about one part in ten thousand, roughly 100 ppm (0.01 wt%). Dose to the demulsibility result rather than a fixed percentage, and avoid over-treating, since too much demulsifier can cause haze in the oil. Confirm the optimum for your oil with our team.
Is it suitable for turbine and hydraulic oils?
Yes. Demulsibility (ASTM D1401) is a defining property of turbine and hydraulic oils because water and steam ingress are common, and a non-ionic polyether demulsifier is the standard way to restore fast water separation. The TDS highlights marine lubricating oil in particular, and the same chemistry serves turbine, hydraulic and circulating oils.