Technical Specifications
This grade family is available as 2 CheMost grades — the differences are in the columns below.
| Property | Unit | J0010 | J0050 | Test Method |
|---|---|---|---|---|
| Shear Stability Index (SSI) | 23 | 40 | ASTM D6022 | |
| Ethylene content | % | 51.5 | 55.5 | ASTM D3900 |
| Mooney Viscosity ML(1+4) 100°C | 10 | 47 | ASTM D1646 | |
| Volatile matter content | % | 0.35 | 0.20 | ASTM D5668 |
| Ash matter content | % | 0.02 | 0.02 | ASTM D297 |
| Vanadium content | µg/g | 1 | 1 | — |
| Solubility (Mineral Group I–III) | >8% | >8% | — | |
| Appearance | White transparent lump | White transparent solid | 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 · ethylene-propylene copolymer (EPM)
–[CH₂–CH₂]ₓ–[CH₂–CH(CH₃)]ᵧ–
Idealised repeat unit of the amorphous ethylene–propylene copolymer (EPM); both grades sit in the amorphous 45–55 % ethylene band.
What Is a Solid Ethylene-Propylene Copolymer (EPM) Base Polymer?
CheMost supplies a solid ethylene-propylene copolymer (EPM) — the raw, amorphous olefin copolymer that a blender dissolves in oil to make an OCP viscosity index improver. It is the same ethylene-propylene chemistry that dominates the engine-oil viscosity-modifier market, supplied here as a base polymer rather than a ready-made concentrate: a white, transparent bale produced by PetroChina, with high thickening efficiency and excellent shear stability.
Because the ethylene/propylene ratio sits in the amorphous band (about 45–55% ethylene), the polymer is soft and cold-flows at room temperature, so it is shipped as compressed bales in rigid boxes. To use it, the blender grinds the bale and dissolves the crumb into a high-quality diluent oil at roughly 100–130°C with agitation; the dissolved polymer then thickens the finished oil and raises its viscosity index exactly as a liquid concentrate would. The pay-off for that extra in-house step is a lower cost per unit of active polymer.
This page covers two base-polymer grades — J0010 and J0050 — which differ in molecular weight (Mooney viscosity), ethylene content and shear stability, set out grade-by-grade in the Technical Specifications table above. Blenders without dissolving capacity can take the identical OCP chemistry as a ready-to-meter liquid concentrate instead.
How an EPM Base Polymer Works
Dissolve, then thicken
The solid bale carries no diluent oil, so it must first be ground and dissolved in hot base oil (≈100–130°C) to form a polymer-in-oil solution. Once dissolved, the ethylene-propylene chains expand as the finished oil heats, offsetting the base oil’s thinning and building high-temperature viscosity — the same temperature-responsive mechanism behind every multigrade oil.
Mooney viscosity tracks molecular weight
The Mooney viscosity (ML 1+4 at 100°C) is the raw-polymer measure of molecular weight: J0010 is a low-Mooney, lower-molecular-weight grade and J0050 a higher-Mooney, higher-molecular-weight grade. Higher molecular weight means more thickening per unit of polymer, but also a higher shear stability index — the central trade-off between the two grades.
Ethylene content & thickening efficiency
Thickening efficiency rises with ethylene content, so J0050 (55.5% ethylene) thickens more efficiently than J0010 (51.5%). Both stay within the amorphous 45–55% band, below the ~60% threshold where long ethylene runs crystallise — so neither behaves as a wax-sensitive low-temperature OCP, and both dissolve cleanly in mineral base oils.
Shear stability & stay-in-grade
The shear stability index (SSI, ASTM D6022) is the fraction of polymer-contributed viscosity permanently lost under shear. J0010’s lower SSI makes it the more shear-stable, stay-in-grade choice, while J0050’s higher SSI buys greater thickening efficiency where shear severity is less critical.
Choosing Between J0010 and J0050
Both grades are the same amorphous ethylene-propylene base polymer; the choice is the classic viscosity-modifier trade-off between thickening efficiency and shear stability, read straight from the Technical Specifications table above.
J0010 — low Mooney, maximum shear stability. A low-molecular-weight grade (Mooney 10) with the lower SSI (23), so it resists permanent viscosity loss best and keeps a multigrade oil in grade through high-shear service. It is the choice for high-grade passenger-car and heavy-duty engine oils where shear durability and long drain intervals matter most. Because its thickening efficiency is lower, it needs a little more polymer to reach a given viscosity.
J0050 — higher Mooney, maximum thickening efficiency. A higher-molecular-weight, higher-ethylene grade (Mooney 47, SSI 40) that reaches a target viscosity at a lower polymer level and offers strong, economical thickening. It is well suited to medium-grade gasoline and diesel engine oils and industrial oils where the highest shear stability is not the governing requirement — the higher ethylene content also gives it good low-temperature behaviour with a matched pour-point depressant.
In short: pick J0010 when shear durability and stay-in-grade performance lead the specification, and J0050 when thickening efficiency and cost-in-use lead it. Our technical team can advise on the right grade and the dissolution conditions for your base oil on request.
Applications
This EPM base polymer is dissolved into a concentrate and used as the viscosity-modifier component in formulations targeting the categories below; it provides viscosity build and viscosity-index improvement only, with no detergency, dispersancy or antiwear of its own.
Multigrade engine oils (PCMO & HDDEO)
The primary use: making the viscosity modifier for multigrade passenger-car and heavy-duty diesel oils (for example SAE 10W-30, 15W-40). J0010 suits high-grade and long-drain engine oils where shear stability is critical; J0050 suits medium-grade gasoline and diesel oils.
Industrial multigrade oils
Dissolved OCP from these bales builds viscosity index in industrial and circulating oils, giving a flatter viscosity-temperature curve and a longer-lived multigrade industrial lubricant.
In-house concentrate production
For blenders who run their own polymer-dissolving line, the bale is the economical feedstock: ground and dissolved in diluent oil, it yields a custom liquid OCP concentrate tuned to the SSI and viscosity the formulation needs.
Custom shear-stability blends
Because J0010 and J0050 sit at different points on the shear-stability/thickening curve, they can be dissolved alone or together to hit an intermediate SSI target that a single grade would not reach.
Finished-oil OEM and industry approvals (API, ACEA, ILSAC and OEM bench sequences) are held by the fully formulated oil, not by an individual viscosity modifier or its base polymer.
Treat Rate & Formulation Notes
The technical data sheet specifies the base polymer itself and does not give a finished-oil treat rate, because the effective dose depends on the diluent oil you dissolve it into and your viscosity target. As an indicative guide grounded in published engine-oil data, roughly 0.5–1.5 wt% of neat polymer is enough to lift a base oil to a multigrade viscosity target:
J0050 (higher thickening efficiency) → lower end · J0010 (more shear-stable) → higher end
Because thickening efficiency scales with molecular weight and ethylene content, the higher-Mooney J0050 reaches a viscosity target at the lower end of that band, while the more shear-stable J0010 sits higher. In practice the bale is first dissolved into a liquid concentrate (typically a few hundred to ~1500 mm²/s at 100°C) and that concentrate is metered into the blend. Low-temperature pumpability is controlled jointly by the base oil, the dissolved OCP and the pour-point depressant, which must be co-optimised — the PPD, not the polymer, is the primary cold-flow control.
The figures above are indicative and derived from typical formulating practice, not a fixed dosage from the TDS; the correct level depends on your diluent oil, viscosity target and the rest of the package. CheMost can provide dissolution and treat-rate support on request.
Formulating With an EPM Viscosity Modifier — Complementary Additives
The dissolved OCP controls viscosity only; a finished multigrade oil pairs it with the additives that cover the rest of the performance envelope:
Pour-point depressants
The PPD is the primary control over low-temperature pumpability and must be matched to the base oil and the viscosity modifier together. Amorphous EPM grades like these are generally well-behaved with conventional PPDs, without the wax-interaction sensitivity of high-ethylene low-temperature OCPs.
Ashless dispersants
Dispersants suspend soot and sludge — a function the base polymer does not provide. The dispersant–detergent–viscosity-modifier balance is the backbone of any multigrade crankcase formulation.
Antioxidants
Aminic and phenolic antioxidants protect the base oil and the dissolved polymer from oxidative breakdown, preserving the viscosity the OCP builds across the drain interval.
Detergents & TBN boosters
In an engine-oil package the viscosity modifier sets the grade while overbased detergents, dispersants and the ZDDP antiwear system deliver cleanliness, acid control and wear protection.
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 Mooney/shear-stability grades and packaging on request.
Formulation support
Dissolution conditions, grade selection and treat-rate guidance from our technical team.
Packaging & Supply
This EPM base polymer is stocked and shipped worldwide, with a typical lead time of 1–15 days and a 48-month shelf life at ambient temperature (maximum storage 50°C; maximum blending/dissolving temperature 70°C for the diluent oil). Samples and quotations are answered within 12 hours.
Packaging
25 kg bag · 42 bags per box · 1050 kg per box.
Minimum order
1 box — 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 solid ethylene-propylene copolymer (EPM) viscosity index improver?
It is the raw ethylene-propylene base polymer that blenders dissolve in oil to make an OCP viscosity modifier. Supplied as an amorphous solid bale, it is ground and dissolved in hot diluent oil (about 100–130°C) to form a polymer-in-oil concentrate that then thickens a finished oil and raises its viscosity index. CheMost offers two grades — J0010 and J0050 — that differ in molecular weight, ethylene content and shear stability.
What is the difference between J0010 and J0050?
Both are amorphous ethylene-propylene base polymers, differing along the thickening-efficiency-versus-shear-stability axis. J0010 is a low-Mooney (10), low-SSI (23) grade — the more shear-stable, stay-in-grade choice for high-grade and long-drain engine oils. J0050 is a higher-Mooney (47), higher-ethylene (55.5%), higher-SSI (40) grade that thickens more efficiently, suited to medium-grade gasoline and diesel oils. The full specifications are in the table above.
Is this the same as EPDM rubber or the cosmetic ethylene/propylene copolymer?
It is the lubricant-grade ethylene-propylene copolymer (EPM), sometimes also called EPM, EPDM or EPR in the additive trade — a low-molecular-weight, oil-soluble grade made specifically as a viscosity index improver. It is not the high-molecular-weight EPDM elastomer used for seals and roofing, and not the “ethylene/propylene copolymer” listed as a cosmetic (INCI) ingredient. Those share the monomers but are different products for different uses.
Do I need to dissolve the bale before use?
Yes. The solid bale carries no diluent oil, so it must be ground and dissolved into a high-quality base oil at roughly 100–130°C with good agitation to form a liquid concentrate before it is blended with other additives. If you do not have polymer-dissolving capacity, the same OCP chemistry is available as a ready-to-meter liquid concentrate.
How much polymer do I need in the finished oil?
As an indicative guide, roughly 0.5–1.5 wt% of neat polymer lifts a base oil to a multigrade viscosity target, with the higher-thickening J0050 at the lower end and the more shear-stable J0010 higher. The TDS specifies the base polymer rather than a finished-oil dose, because the exact level depends on the diluent oil and your viscosity target — so treat these figures as indicative and confirm with our team for your formulation.