Polymethacrylate (PMA) Viscosity Index Improver
CAS Number: 25087-26-7
Polymethacrylate (PMA) viscosity index improvers are comb-polymer additives that reduce the change in viscosity with temperature, enabling the formulation of multi-grade engine oils and gear oils with excellent low-temperature fluidity and high-temperature viscosity retention. PMA VI improvers also provide inherent pour point depressant functionality. They are extensively used in passenger car motor oils (0W-20 to 5W-40), ATF, and gear oils requiring both viscosity modification and low-temperature performance.
Technical Specifications
| appearance | Amber to dark amber viscous liquid or solid |
| flash point (COC) | >180 °C |
| molecular weight (Mw) | 50,000–500,000 Da |
| shear stability index (SSI) | 10–50 (application dependent) |
| active ingredient in diluent | 40–70 wt% |
| kinematic viscosity of concentrate (100°C) | 200–5000 mm²/s |
Applications
- Passenger car motor oils (0W-20, 5W-30, 5W-40, 10W-40) multi-grade formulations
- Automatic transmission fluids (ATF) and CVT fluids with wide temperature operating range
- Industrial hydraulic oils (ISO VG 22–100 multi-grade)
- Power steering fluids and electric power steering fluids
- Gear oils requiring low-temperature fluidity and high-temperature viscosity retention
Key Features
- Dual VI improvement and pour point depression in one molecule reduces additive package complexity
- Excellent shear stability (low SSI) maintains viscosity grade throughout the oil drain interval
- Enables low-viscosity multi-grade engine oil formulations (0W-16 to 0W-20) for fuel economy
- Available in a wide molecular weight range to optimize the balance of VI improvement and shear stability
Grade Variants & Supplier Reference
Specific grades available from leading Chinese-market suppliers. Spec sheets and lead-time vary per grade — request a quote to confirm availability.
Spec sheet not published — request TDS via inquiry form.
Polymethacrylate copolymer; treat rate ~3-7% depending on viscosity grade target.
View on supplier site →Big 4 Equivalents Cross-Reference
Approximate functional equivalents from leading global additive houses (Lubrizol, Infineum, Afton Chemical, Chevron Oronite). Chemistry tier, treat rate, and additive synergy may differ — always verify against the supplier TDS before formulation lock-in.
- (Lubrizol exited PMA business — now serviced via Evonik Viscoplex)
- SV-261 (PMA VII)
- SV-251 (PMA VII for engine oil)
- HiTEC 5777 (PMA)
- HiTEC 5710 (multi-grade PMA)
- (Chevron Oronite does not market a PMA VII line)
Send Inquiry
CAS Number
25087-26-7
Category
Automotive Lubricant AdditivesAvailability
In StockSample
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