Hydrogenated Styrene-Diene Copolymer (HSD)
Hydrogenated styrene-diene copolymer (HSD) — a star-structured viscosity modifier with very high shear stability, ideal for long-drain diesel oils and high-performance multigrade oils.
The shear-stable viscosity modifier for long drains
When an oil must hold its viscosity grade through long, high-shear service, HSD delivers — its star-structured polymer resists permanent shear thinning where other VMs would shear down.
Hydrogenated styrene-diene copolymer (HSD) is a high-performance viscosity modifier known for its very high shear stability (very low SSI). Its hydrogenated, often star-shaped polymer structure resists permanent viscosity loss under mechanical shear, so the oil holds its grade through long, demanding service. This makes HSD ideal for long-drain heavy-duty diesel oils and high-performance multigrade oils where shear durability is critical — the very property that distinguishes it from OCP. It is part of the viscosity index improver range.
Hydrogenated Styrene-Diene Copolymer (HSD) — typical properties
Representative typical values for HSD viscosity modifier. Indicative only — exact values vary by grade and are confirmed on the TDS and batch COA.
| Property | Typical Value | Method / Note |
|---|---|---|
| Appearance | Solid or liquid concentrate | Grade-dependent |
| Polymer type | Hydrogenated styrene-diene | Star structure |
| Shear stability (SSI) | Very low | Very high durability |
| Thickening efficiency | High | Good with shear stability |
| Kinematic viscosity (100°C) | Grade-dependent | ASTM D445 |
| Function | Shear-stable VM | Long-drain |
| Form | Solid / liquid | Various |
Typical values for guidance only — not a specification. Request the TDS for the specific grade you need; the COA reports actual measured values for your batch.
Where HSD viscosity modifier is used
Long-Drain Diesel Oils
Shear-stable viscosity retention for HDDO. See diesel engine oil.
High-Performance Multigrade Oils
Holds grade through demanding high-shear service.
Heavy-Duty Engine Oils
Durable viscosity for extended drain intervals. See engine oil additives.
Premium Oils
Where shear durability justifies a premium VM.
Why formulators choose HSD viscosity modifier
Very high shear stability
Very low SSI — resists permanent viscosity loss where OCP would shear down.
Holds grade through long drains
Maintains viscosity grade through long, high-shear diesel service.
High thickening with durability
Combines good thickening efficiency with outstanding shear durability.
From sample drum to ISO tank
Sinolook supplies HSD viscosity modifier at any scale, from formulation samples to commercial bulk, to over 60 countries.
Other viscosity index improvers
Explore the rest of the viscosity index improver range:
Frequently asked questions
What is hydrogenated styrene-diene copolymer (HSD) used for?
Why is HSD more shear-stable than OCP?
When should I choose HSD over OCP?
What is SSI and why does it matter?
Can Sinolook provide TDS, MSDS and COA?
Request HSD viscosity modifier from Sinolook
Tell us your target grade, application and volume — we'll send the TDS, a batch COA and a delivered quotation within 24 hours.
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