Дициклопентадиен химические свойства, назначение, производство
Химические свойства
Dicyclopentadiene (DCPC) is a dimer of cyclopentadiene. First heating is used to copolymerize cyclopentadiene into dicyclopentadiene, dicyclopentadiene is separated from other light components (boiling point <45°C) by distillation, and then other required dienes, monocyclopentadiene are separated by solvent extraction. Alkene and saturated hydrocarbon components. High-purity dicyclopentadiene is a colorless crystal at room temperature. When it contains impurities, it is a light yellow oily liquid with a pungent camphor smell. It is insoluble in water and soluble in organic solvents such as alcohol and ether.
cyclopentadiene, although a stable molecule, has a strong tendency to form the more stable dimer dicyclopentadiene. This dimerisation already takes place at room temperature and its rate rapidly increases with elevated temperatures. This reaction however is reversible too; dicyclopentadiene "cracks" at temperatures above 140°C to form two cyclopentadiene molecules.
Использование
Dicyclopentadiene is used in resins, particularly unsaturated polyester resins. It plays a major role in inks, adhesives and paints. It is also used as a monomer in polymerization reactions. It is a precursor for the preparation of endo-tetrahydrodicyclopentadiene, which reacts with aluminum chloride at higher temperature to give adamantine. It undergoes a retro-Diels-Alder reaction to yield cyclopentadiene, which acts as ligand in inorganic chemistry.
Подготовка
Dicyclopentadiene is formed by the spontaneous dimerization of cyclopentadiene by Diels-Alder reaction insolution.
Методы производства
Dicyclopentadiene is produced by recovery from hydrocarbon streams from high temperature cracked petroleum fractions. It is also a by-product of the coke oven industry. Cyclopentadiene polymerizes to dicyclopentadiene on standing.
Общее описание
Dicyclopentadiene appears as a liquid with an acrid odor. Flash point 90°F. The vapors are irritating to the eyes and respiratory system. Subject to polymerization if subjected to heat for prolonged periods or if contaminated. If the polymerization takes place inside a container, the container may violently rupture. Insoluble in water. Density 8.2 lb / gal. Used in paints, varnishes, as an intermediate in insecticides, as a flame retardant in plastics.
Реакции воздуха и воды
Highly flammable. Insoluble in water.
Профиль реактивности
Dicyclopentadiene may react vigorously with oxidizing agents. May react exothermically with reducing agents to release hydrogen gas. Can undergo exothermic polymierization reactions In the presence of various catalysts (such as acids) or initiators, if subjected to heat for prolonged periods, or if contaminated. Many undergo autoxidation upon exposure to the air to form explosive peroxides.
Угроза здоровью
LIQUID OR SOLID: Irritating to skin and eyes.
Пожароопасность
FLAMMABLE. Flashback along vapor trail may occur. Vapor may explode if ignited in an enclosed area.
Химическая реактивность
Reactivity with Water No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: May occur in presence of acids, but not hazardous; Inhibitor of Polymerization: Not pertinent.
Профиль безопасности
Poison by ingestion and
intraperitoneal routes. Moderately toxic by
inhalation. Mildly toxic by skin contact. A
severe skin and moderate eye irritant.
Dangerous fire hazard when exposed to heat
or flame; can react with oxidizing materials.
To fight fire, use alcohol foam. When
heated to decomposition it emits acrid
smoke and fumes.
Возможный контакт
This compound is used in the
manufacture of cyclopentadiene as a pesticide intermediate;
in the production of ferrocene compounds; in paints,
varnishes, and resin manufacture; in production of elastomers, resin systems, and polymers.
Канцерогенность
Undiluted dicyclopentadiene caused minor
irritation when applied to the skin of rabbits,
and only trace injury occurred when instilled in
the eye.
Dicyclopentadiene has a camphorlike
odor with a 100% recognition threshold of
0.02ppm; however, there may not be noticeable
irritation below 10ppm.
The 2003 ACGIH threshold limit valuetime-
weighted average (TLV-TWA) for dicyclopentadiene
is 5ppm (27mg/m3).
Перевозки
UN2048 Dicyclopentadiene must carry a
“FLAMMABLE LIQUID” label. It falls in Hazard Class 3
Несовместимости
Forms explosive mixture with air above
flash point. Depolymerizes at boiling point and forms two
molecules of cyclopentadiene; unless inhibited and maintained under inert atmosphere to prevent polymerization.
Violent reaction with strong oxidizers; strong acids; strong
bases. Can accumulate static electrical charges, and may
cause ignition of its vapors
Утилизация отходов
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.
Дициклопентадиен препаратная продукция и сырье
сырьё
препарат