пропин

Химические свойства

Propyne,C3H4, is a colorless, highly flammable, and explosive gas. Sources of propyne emissions to the atmosphere include automobile and turbine exhaust, biomass and polymer combustion, petroleum manufacturing, and tobacco smoke.

Использование

Propyne is produced by thermal or catalytic pyrolysis of propene. Like acetylene, propyne is used as a welding torch fuel, as a specialty fuel, and chemical intermediate.

Общее описание

A colorless liquefied gas with a sweet odor. Mp: -104°C, bp: -23.1°C. Insoluble in water, soluble in ethanol, chloroform and benzene. Moderately toxic by inhalation. Used as a speciality fuel. Denser than air. Vapors may ignite at distant sources of ignition and flash back.

Реакции воздуха и воды

Highly flammable. PEROXIDE FORMING WHICH LEADS TO EXPLOSIONS

Профиль реактивности

Propyne is highly flammable. The liquid material in cylinders contains about 30% propadiene. Detonation may occur at 95° C [MCA Case History No. 632]. Reacts exothermically with many oxidizing agents and with some reducing agents as well. May react with silver, copper, and mercury salts in aqueous solution to give explosive acetylides. Incompatible with brass that contains more than 65% copper, with other copper-containing alloys, with Monel metal, with neoprene, polyethylene, and, to a lesser extent, with Teflon. May enflame in air in the presence of Co, Hg, Hg salts, K, Ag, Ag salts, RbH, CsH, halogens, HNO3, NaH. Can decompose explosively when compressed to 4.5 to 5.6 atmospheres. Moderate explosion hazard when exposed to heat or flame or by spontaneous chemical reaction. Has been known to decompose explosively at high pressures and moderate temperatures in the absence of air.

Опасность

Flammable, dangerous fire risk. Toxic by inhalation. Central nervous system impairment.

Угроза здоровью

At high concentrations methyl acetylene causes narcosis in animals, and it is expected that severe exposure will produce the same effect in humans.

Профиль безопасности

Ths compound is a simple anesthetic and in high concentration is an asphyxiant. Mutation data reported. Dangerous fire hazard when exposed to heat or flame; can react vigorously with oxibzing materials. Explosive in the form of vapor when exposed to heat or flame. Localized heating of liquid-containing cylinders to 95°C may cause an explosion. Product of reaction with silver nitrate ignites at 150°C. A commercial mixture containing 30% propyne in MAPP gas is similar to ethylene in potential hazards and handling requirements. To fight fire, stop flow of gas. When heated to decomposition it emits acrid smoke and irritating fumes. See also ACETYLENE COMPOUNDS.

Возможный контакт

This material may be used as a liquid rocket propellant, in admixture with propadiene as an industrial cutting fuel.

Экологическая судьба

Chemical/Physical. When passed through a cold solution containing hydrobromite ions, 1-bromo-1-propyne was formed (Hatch and Kidwell, 1954).
Combustion products include carbon monoxide, carbon dioxide, and water vapor.

Перевозки

UN3161 Liquefied gas, flammable, n.o.s., Hazard Class: 2.1; Labels: 2.1-Flammable gas, Technical Name Required. Cylinders must be transported in a secure upright position, in a well-ventilated truck. Protect cylinder and labels from physical damage. The owner of the compressed gas cylinder is the only entity allowed by federal law (49CFR) to transport and refill them. It is a violation of transportation regulations to refill compressed gas cylinders without the express written permission of the owner.

Методы очистки

Purify it by preparative gas chromatography. [Beilstein 1 H 246.]

Несовместимости

Forms explosive gas mixture with air. The liquid material in cylinders contains about 30% propadiene. Detonation may occur at 95C. May form explosive peroxides. Can decompose explosively on heating and @ 4.5
5.6 atmospheres of pressure. Strong oxidizers may cause fire and explosions. Forms shock sensitive compounds with copper, magnesium, silver and their alloys. Copper or copper alloys containing more than 67% copper should not be used in handling equipment. Attacks some plastics, rubber and coatings.

Утилизация отходов

Return refillable compressed gas cylinders to supplier. Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.