115-11-7

115-11-7 - Names and Identifiers

Name	Isobutene
Synonyms	Isobutene ISOBUTENE ISOBUTYLENE Isobutylene HP-ISOBUTYLENE 2-methylpropene 2-methyl-propen 2-methyl-1-propen 1,1-dimethylethene 1,1-Dimethylethylene 2-Methylpropene-isobutylene
CAS	115-11-7
EINECS	204-066-3
InChI	InChI=1/C4H8/c1-4(2)3/h1H2,2-3H3
InChIKey	VQTUBCCKSQIDNK-UHFFFAOYSA-N

115-11-7 - Physico-chemical Properties

Molecular Formula	C4H8
Molar Mass	56.11
Density	0.5879
Melting Point	−140°C
Boling Point	−6.9°C(lit.)
Flash Point	-80°C
Water Solubility	263mg/L(25 ºC)
Vapor Presure	3278 mm Hg ( 37.7 °C)
Vapor Density	2 (vs air)
Appearance	clear liquid
Color	Colorless to Almost colorless
Merck	14,5141
BRN	773645
Stability	Stable. Highly flammable - readily forms an explosive mixture with air. Incompatible with strong oxidizing agents.
Refractive Index	1.3811
Physical and Chemical Properties	Boiling point 6.9 ℃ freezing point -140.34 ℃ relative density 0.5879 refractive index 1.3811
Use	Water can be prepared tert-butyl alcohol, oxidation of methacrolein and methacrylic acid, ammonia oxidation of methacrylonitrile, etc

115-11-7 - Risk and Safety

Hazard Symbols	F+ - Highly flammable
Risk Codes	12 - Extremely Flammable
Safety Description	S9 - Keep container in a well-ventilated place. S16 - Keep away from sources of ignition. S33 - Take precautionary measures against static discharges.
UN IDs	UN 1055 2.1
WGK Germany	-
RTECS	UD0890000
FLUKA BRAND F CODES	4.5-31
HS Code	29012330
Hazard Class	2.1
Packing Group	III
Toxicity	LC50 (inhalation) for mice 415 g/m3/2-h, rats 620 g/m3/4-h (quoted, RTECS, 1985).

115-11-7 - Upstream Downstream Industry

Downstream Products

p-tert-butyl toluene
3-Chloro-2-methylpropene
2,6-Di-tert-butylphenol
tert-Butylhydroquinone
6-tert-Butyl-3-methylphenol
Triisobutylaluminum
p-tert-Butylphenol
Antioxidant 300
2,4-Di-tert-butylphenol
2,6-Di-tert-butyl-4-methylphenol

115-11-7 - Nature

Open Data Verified Data

at room temperature and atmospheric pressure, isobutylene is a colorless combustible gas with a gas-like odor.

Last Update：2024-01-02 23:10:35

115-11-7 - Hair-making

Open Data Verified Data

Industrial isobutylene is used as a raw material (isobutylene 99%), which can be dried, dehydrated and purified by distillation.

Last Update：2022-01-01 09:31:43

115-11-7 - Use

Open Data Verified Data

high purity isobutylene is mainly used as standard gas and special standard mixture.

Last Update：2022-01-01 09:31:44

115-11-7 - Safety

Open Data Verified Data

isobutylene has a slight stimulating effect on the mucosa and has an anesthetic effect on the human body. Inhalation of high concentrations of isobutylene can produce a asphyxiating effect. Skin contact with liquid isobutylene can cause frostbite. The toxicity of isobutylene is 4.5 times that of ethylene. Maximum allowable concentration: 400 x 10-6. Gas cylinders should be stored in a cool and well-ventilated place, away from heat source and fire, with oxygen, chlorine, high oxidation and flammable substances Isolation. All equipment and lines shall be grounded.

Last Update：2022-01-01 09:31:44

115-11-7 - Reference Information

cylinders for combustion-supporting gases

olfactory Threshold	10ppm
freezing point	-140.34 ℃
Henry's Law Constant	0.20, 0.26, 0.33, and 0.41 at 30, 40, 50, and 60 °C, respectively (Leung et al., 1987:Zhang et al.,2002)
LogP	2.35 at 20℃
EPA chemical substance information	information provided by: ofmpeb.epa.gov (external link)
Introduction	isobutylene is also known as 2-methylpropene. Industrially, isobutylene is almost always obtained from refinery gas and cracking C4 fraction. The content of Isobutene in the refinery gas is generally 5-12%, and that in the cracking C4 fraction is generally 20%-30%.
Application	the chemical utilization of isobutylene can be divided into two categories, one is mixed C (extracted butadiene) direct Utilization of fractions and processing utilization of high-purity isobutene.
Application	isobutylene, also known as 2-methylpropene, is an important petrochemical raw material, in the pesticide industry, it is mainly used for the preparation of organophosphorus insecticide terbuthyl phosphorus, pyrethroid insecticide permethrin and acaricide pyridaben and other varieties, at the same time, isobutylene is also widely used in light industry, oil refining, medicine, spices, building materials and other fine chemicals and other departments. high concentration of isobutylene is mainly used in the production of polyisobutylene and isoprene copolymerization to produce butyl rubber. High-octane alkylated gasoline can be produced by alkylation of isobutene with isobutane. Methyl tert-butyl ether obtained by reaction with methanol is an excellent gasoline additive. It is also suitable for use as a raw material for alkylation of aromatic hydrocarbons, or fine chemicals produced by oxidation, ammonification and other operations. 2-tert-butyl-p-cresol, a derivative of Isobutene, is coupled with 2-nitro-5-chloroaniline diazonium and then reduced to obtain 2,3 '-tert-butyl -2'-hydroxy-5 '-methylphenyl-5-chlorobenzotriazole is a good ultraviolet absorber. Also, 2-tert-butyl-4, 6-dinitrophenol, which is an agricultural herbicide, is obtained by nitration of O-tert-butylphenol. adding water to prepare tert-butyl alcohol, oxidation to methacrolein and methacrylic acid, ammoxidation to methacrylonitrile, etc.
production method	Isobutene is obtained industrially from almost all refinery gases and cracked C4 fractions. The content of Isobutene in the refinery gas is generally 5-12%, the cracking C4, and the fraction is generally 20%-30%. In a few cases, a chromium oxide-alumina catalyst is used to catalyze hydrogen from isobutane. When propylene oxide is produced from propylene and isobutane by co-oxidation, isobutylene is the co-product. There are many preparation methods of isobutene. At present, methyl tert-butyl ether is mainly used in the production, that is, methyl tert-butyl ether (MTBE) is obtained by catalytic etherolysis. (CH3)3COCH3 [catalyst] →(CH3)2C = CH2 + CH3OH catalytic etherolysis reaction catalysts used in Al2O3, sulfate, phosphate, the reaction temperature of uranium oxide, hydroxide and activated carbon is 150~300 ℃, the reaction pressure is 0.3~0.6MPa, and the volume space velocity of liquid is 1~5h-1. When modified Al2O3 was used as catalyst and the temperature was 180 ℃, the recovery rate of isobutylene reached 100%. Further, there are absorption and separation methods using sulfuric acid or hydrochloric acid from the C4 fraction, isobutane dehydrogenation method, tert-butyl alcohol dehydration method, ion exchange method, adsorption method, selective polymerization separation method and the like.
category	hazardous gas
toxicity grade	low toxicity
Acute toxicity	inhalation-rat LC50:620g/m3/2 H; Inhalation-mouse LC50:415g/m3/2 h
explosive hazard characteristics	open flame mixed with air, thermal explosion
flammability hazard characteristics	open flame, combustible under heat; Combustion-induced smoke
storage and transportation characteristics	The warehouse is ventilated and dried at low temperature; Light loading and light unloading; And oxygen, separate storage of
fire extinguishing agent	water mist, carbon dioxide, foam
Occupational Standard	SEL 100 mg/m3
spontaneous combustion temperature	869 ° F.
DOT Classification	2.1 (Flammable gas)
toxic substance data	information provided by: pubchem.ncbi.nlm.nih.gov (external link)