Methyl Tertiary Butyl Ether (MTBE)
Other Names
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MTBE
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Tertiary-Butyl Methyl Ether
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2-Methoxy-2-methylpropane
CAS Number: 1634-04-4
Chemical Formula: C₅H₁₂O
Molecular Weight: 88.15 g/mol
📘 1. Definition
Methyl Tertiary Butyl Ether (MTBE) is a volatile, colorless liquid that is widely used as a fuel additive to increase the octane rating and reduce engine knocking. MTBE improves combustion efficiency and reduces emissions of carbon monoxide and certain hydrocarbons. It is also used as a solvent in chemical synthesis and industrial applications due to its high solubility in organic solvents and low water solubility.
🧪 2. Physical & Chemical Properties
| Property | Value |
|---|---|
| Chemical Formula | C₅H₁₂O |
| Molecular Weight | 88.15 g/mol |
| Appearance | Colorless liquid |
| Odor | Ether-like, slightly sweet |
| Boiling Point | 55–56 °C |
| Melting Point | -109 °C |
| Flash Point | -28 °C |
| Density | 0.74 g/cm³ at 20 °C |
| Vapor Pressure | 352 mmHg at 20 °C |
| Solubility | Slightly soluble in water; miscible with most organic solvents |
| Stability | Stable under normal conditions; reacts with strong acids and oxidizers |
🧰 3. Applications / Uses
| Industry | Applications |
|---|---|
| Fuel Industry | Octane booster in gasoline, anti-knock agent, oxygenate additive |
| Chemical Industry | Solvent for extraction, chemical synthesis intermediate |
| Laboratory Use | Solvent for organic reactions, chromatographic solvent |
| Industrial Applications | Degreasing solvent, intermediate for chemical manufacturing |
⚠️ 4. Safety & Handling
| Hazard | Details |
|---|---|
| Flammability | Highly flammable liquid and vapor |
| Health Hazards | Exposure may cause dizziness, headache, nausea, or respiratory irritation; long-term exposure may affect the liver and kidneys |
| Environmental | Contaminates groundwater; persistent in the environment |
| PPE | Gloves, goggles, and proper ventilation recommended |
| Storage | Store in cool, well-ventilated area, away from heat, sparks, and open flames |
| Exposure Limits | OSHA PEL: 100 ppm; ACGIH TLV: 50 ppm |
📌 5. Summary
Methyl Tertiary Butyl Ether (MTBE) is a volatile ether used mainly as a gasoline additive to improve octane rating and reduce engine knock. It also serves as a solvent and chemical intermediate in industrial applications. MTBE is highly flammable, slightly soluble in water, and can pose environmental hazards if released into groundwater, so careful handling and storage are required.
