Product Details
Tert-Butyl Methyl Ether CAS#1634-04-4
Methyl tert-butyl ether (widely known as MTBE) is a colorless liquid with a distinct, pungent odor, synthesized via the reaction of isobutylene and methanol. Since the 1980s, it has been a standard unleaded gasoline additive, engineered to enable far cleaner, lower-emission fuel combustion.
Beyond fuel applications, MTBE also serves a niche medical use for gallstone dissolution. In this targeted clinical procedure, MTBE is perfused directly into the gallbladder through specially placed surgically inserted catheters.
tert-Butyl methyl ether Chemical Properties
| Melting point | -110 °C |
| Boiling point | 55-56 °C(lit.) |
| density | 0.7404 |
| vapor density | 3.1 (vs air) |
| vapor pressure | 4.05 psi ( 20 °C) |
| refractive index | n20/D 1.369(lit.) |
| Fp | -27 °F |
| storage temp. | Store at +2°C to +25°C. |
| solubility | 42g/l |
| form | Powder or Needles |
| color | APHA: ≤10 |
| Specific Gravity | 0.74 |
| Odor | Characteristic ethereal odor |
| Relative polarity | 0.124 |
| explosive limit | 1.5-8.5%(V) |
| Water Solubility | 51 g/L (20 ºC) |
| FreezingPoint | -108.6℃ |
| λmax | λ: 210 nm Amax: 1.0 |
| λ: 225 nm Amax: 0.50 | |
| λ: 250 nm Amax: 0.10 | |
| λ: 300-400 nm Amax: 0.005 | |
| Merck | 146032 |
| BRN | 1730942 |
| Exposure limits | ACGIH: TWA 50 ppm |
| Dielectric constant | 4.5 |
| Stability: | Stable, but may form explosive peroxides in contact with air. Extremely flammable - note low flash point. Incompatible with strong oxidizing agents. |
| InChIKey | BZLVMXJERCGZMT-UHFFFAOYSA-N |
| LogP | 1.06 at 20℃ |
| CAS DataBase Reference | 1634-04-4(CAS DataBase Reference) |
| IARC | 3 (Vol. 73) 1999 |
| NIST Chemistry Reference | Propane, 2-methoxy-2-methyl-(1634-04-4) |
| EPA Substance Registry System | Methyl tert-butyl ether (1634-04-4) |
| Hazard Codes | Xn,F,Xi,T |
| Risk Statements | 36/37/38-40-38-11-39/23/24/25-23/24/25 |
| Safety Statements | 9-16-24-45-36/37-7 |
| RIDADR | UN 2398 3/PG 2 |
| WGK Germany | 3 |
| RTECS | KN5250000 |
| F | 46091 |
| Autoignition Temperature | 705 °F |
| TSCA | Yes |
| HS Code | 2909 19 90 |
| HazardClass | 3 |
| PackingGroup | II |
| Hazardous Substances Data | 1634-04-4(Hazardous Substances Data) |
| Toxicity | . LC50 in mice (15 min): 1.6 mmol/liter of atmosphere (Marsh) |
Product Usage
Prior to 2005, methyl tert-butyl ether (MTBE) was a mainstream unleaded gasoline additive widely adopted across the United States. It also serves as a key raw material for isobutene production, and functions as a chromatographic eluent, especially for high-performance liquid chromatography workflows.
Beyond these industrial uses, MTBE has established pharmaceutical applications, where it can be delivered directly into the gallbladder to dissolve gallstones (ATSDR, 1996). In the petrochemical sector, tert-butyl methyl ether can also undergo a reversed synthesis reaction: under temperatures higher than its production conditions, it can be catalytically cracked over acidic catalysts to yield pure isobutene and methanol.
