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Isobutylene CAS 115-11-7

Chemical formula: C4H8 Structural formula: (CH3)2C=CH2 CAS number: 115-11-7 Molecular weight: 56.11 English name: Isobutylene; 2-methylpropene ...

Release time：2025-05-01

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Isobutylene is an important petrochemical raw material. The following is a detailed introduction to it:

1. Basic information

Chemical formula: C4H8

Structural formula: (CH3)2C=CH2

CAS number: 115-11-7

Molecular weight: 56.11

English name: Isobutylene; 2-methylpropene

2. Physical properties

State: colorless gas (may also appear as colorless liquid in some cases)

Melting point: -140.35 (or -140)

Boiling point: -6 .8 (or -6.9)

Density: 0.5879 (relative density in gaseous state may be different)

Vapor density: 2 (relative to air)

Vapor pressure: 3278mmHg (at 37.7)

Refractive index: 1.3811

Flash point: -80

Odor threshold: 10ppm

Water solubility: 263mg/L (at 25)

III. Chemical properties

Stability: Stable, but highly flammable, easy to form explosive mixture with air, explosion limit is 1.7%~9.0% (volume fraction).

Reaction characteristics: soluble in organic solvents, easy to polymerize. Incompatible with strong oxidants.

IV. Main uses

Pesticide industry: used to prepare organophosphorus insecticide terbuthion, pyrethroid insecticide permethrin and acaricide pyridaben, etc.

Other industries: widely used in light industry, oil refining, medicine, spices, building materials and other fine chemicals. For example, it is used to produce polyisobutylene, butyl rubber, high-octane alkylated gasoline, methyl tert-butyl ether (excellent gasoline additive), etc.

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