2,2,4-トリメチルペンタン 化学特性,用途語,生産方法
外観
無色澄明の液体
性質
异辛烷的熔点为-107℃，沸点为99℃。 它在室温和压力下是无色液体，在石油中含有微量。
不溶于水，但能与烃类溶剂以任意比例混合。
溶解性
水に難溶, エタノール, エーテルに混和。エタノール及びジエチルエーテルに極めて溶けやすく、水に溶けにくい。
解説
イソオクタンとは、炭素数8個の飽和炭化水素のうち、分岐した化合物の1つです。
燃料分野では、2,2,4-トリメチルペンタン (英: 2,2,4-Trimethylpentane) と呼ばれています。燃焼が安定しているため、オクタン価 (英: octane ratingまたはoctane number) の基準になっています。消防法では「第4類危険物第1石油類」に該当します。
| 化学式 |
C8H18 |
| 英語名 |
Isooctane |
| 分子量 |
114.23 |
用途
抽出溶媒、有機合成用溶剤、オクタン価測定用。
用途
溶剤、抽出溶媒、有機合成用溶剤、塗料、接着剤。
用途
比色分析、紫外吸光分析、高感度機器分析用溶媒、抽出溶媒。
用途
ビール苦味成分定量用抽出溶剤。
用途
液体クロマトグラフ用溶離液調製用。
用途
スペクトル用
構造
イソオクタンの分子式はC8H18、分子量は114.23、密度は0.69 g/cm3です。分枝状に3つのメチル基がに結合した構造をしています。示性式はCH3C(CH3)2CH2CH(CH3)2です。
18種類の構造異性体が存在します。ただし、立体異性体も考えると24種類です。
合成
イソオクタンは、イソブタンをイソブチレンによってアルキル化することで生成可能です。イソブチレンを・などを用いて二量化し、生成されたジイソブチレンを水素化することでも得られます。
使用上の注意
不活性ガス封入
説明
Isooctane is a flammable liquid isomer of octane. It is best known for defining the octane
number to rate the antiknock quality of gasoline, which is related to engine performance.
Since 1930, many chemical processes, such as alkylation
and polymerization, have been developed to increase the production of branched compounds
in refi nery operations. High octane numbers in gasoline are those associated with the alkenes
(olefins) and aromatics, especially akyl benzene compounds. For example, 2-pentene has a
RON of 154. Benzene itself has a RON of 98, but 1,3,5-trimethylbenzene has a RON of 170.
The highest octane numbers in gasoline are associated with cyclic alkenes, but these account
for only a minute fraction of gasoline.
化学的特性
2,2,4-Trimethylpentane (isooctane), C8H18, is a colorless
liquid naturally found in crude petroleum and in small
amounts in natural gas. It is released to the
environment by the petroleum industries, by automotive
exhausts and emissions, and from hazardous-waste sites,
landfills, and emissions from wood combustion.
物理的性質
Octane is a colorless liquid with a gasoline-like odor. The odor threshold is 4 ppm and 48 ppm (New Jersey Fact Sheet). An odor threshold concentration of 670 ppbv was reported by Nagata and Takeuchi (1990).
使用
2,2,4-Trimethylpentane is used as a mobile phase in High Performance Liquid Chromatography and Liquid Chromatography coupled with Mass Spectrometry.
調製方法
Isooctane is produced from the fractional distillation of
petroleum fractions and naphthas. It is also produced from
the alkylation of 2-methylpropene with isobutane.
定義
ChEBI: 2,2,4-Trimethylpentane is an alkane that consists of pentane bearing two methyl substituents at position 2 and a single methyl substituent at position 4.
一般的な説明
A clear colorless liquid with a petroleum-like odor. Flash point 10°F. Less dense than water and insoluble in water. Vapors are heavier than air.
空気と水の反応
Highly flammable. Insoluble in water.
反応プロフィール
Saturated aliphatic hydrocarbons, such as 2,2,4-Trimethylpentane, may be incompatible with strong oxidizing agents like nitric acid. Charring of the hydrocarbon may occur followed by ignition of unreacted hydrocarbon and other nearby combustibles. In other settings, aliphatic saturated hydrocarbons are mostly unreactive. They are not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents.
危険性
Intermediate, azeotropic distillation entrainer.
健康ハザード
Inhalation or contact with material may irritate or burn skin and eyes. Fire may produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.
火災危険
Highly flammable liquid; flash point (closed
cup) －12.2°C (10°F); autoignition temperature
418°C (784°F) (NFPA 1997); fireextinguishing
agent: dry chemical, foam, or
CO2; use a water spray to keep fire-exposed
containers cool. Isooctane forms explosive
mixtures with air within the range 1–4.6%
by volume of air.
使用用途
イソオクタンは、オクタン価を測定するため、正標準燃料 (オクタン価100) として使用されています。また、高オクタン価ガソリン製造のための混合材としても利用可能です。オクタン価の高い燃料は、アンチノック性が低いため、自動車エンジンの稼働に適しています。
他にも、「溶剤」「抽出溶媒」「有機合成用溶剤」「エアゾール溶剤」「修正液用剤」「金属洗浄剤」「インキ」「塗料」「」などとしての用途もあります。さらに、高速液体クロマトグラフィなどの「分析用の溶媒」として用いることも可能です。
安全性プロファイル
Mutation data reported.
High concentrations can cause narcosis. A
very dangerous fire hazard when exposed to
heat, flame, oxidmers. Can react vigorously
with reducing materials. Explosive in the
form of vapor when exposed to heat or
flame. To fight fire, use CO2, dry chemical.
When heated to decomposition it emits
acrid smoke and irritating fumes. See also
ALKANES.
職業ばく露
Octane is used as a solvent; as a
fuel; as an intermediate in organic synthesis; and in
azeotropicdistillations.
発がん性
Male and female rats were initiated
with 170 ppm N-ethyl-N-hydroxyethylnitrosamine for
2 weeks and subsequently exposed to isooctane for 61
weeks. An increase in atypical cell foci (a preneoplastic
lesion) was observed in male but not female rats promoted
with the high dose.
環境運命予測
Surface Water. Mackay and Wolkoff (1973) estimated an evaporation half-life of 4.1 sec from a
surface water body that is 25 °C and 1 m deep.
Photolytic. The following rate constants were reported for the reaction of 2,2,4-trimethylpentane
and OH radicals in the atmosphere: 2.3 x 10
-12 cm
3/molecule?sec at 300 K (Hendry and
Kenley, 1979); 2.83 x 10
-12 cm
3/molecule?sec at 298 K (Greiner, 1970); 3.73 x 10
-12
cm
3/molecule?sec at 298–305 K (Darnall et al., 1978); 3.7 x 10
-12 cm
3/molecule?sec (Atkinson et
al., 1979); 3.90 x 10
-12 cm
3/molecule?sec at 298 K (Atkinson, 1985). Based on a photooxidation
rate constant of 3.68 x 10
-12 cm
3/molecule?sec for the reaction of 2,2,4-trimethylpentane and OH
radicals in summer sunlight, the lifetime is 16 h (Altshuller, 1991).
Products identified from the reaction of 2,2,4-trimethylpentane with OH radicals in the presence
of nitric oxide included acetone, 2-methypropanal, 4-hydroxy-4-methyl-2-pentanone, and hydroxy
nitrates (Tuazon et al., 2002).
Chemical/Physical. Complete combustion in air produces carbon dioxide and water vapor.
2,2,4-Trimethylpentane will not hydrolyze in water.
輸送方法
UN1262 Octanes, Hazard Class: 3; Labels:
3-Flammable liquid.
純化方法
Distil isooctane from sodium, pass it through a column of silica gel or activated alumina (to remove traces of olefins), and again distilled from sodium. Extract repeatedly with conc H2SO4, then agitate it with aqueous KMnO4, wash it with water, dry (CaSO4) and distil it. Purify it also by azeotropic distillation with EtOH, which is subsequently washed out with water, and the trimethylpentane is dried and fractionally distilled. [Forziati et al. J Res Nat Bur Stand 36 126 1946.] [Beilstein 1 IV 439.]
不和合性
Reacts with strong oxidizers, causing fire
and explosion hazard. Attacks some forms of plastics, rubber
and coatings.
廃棄物の処理
Dissolve or mix the material
with a combustible solvent and burn in a chemical incinerator
equipped with an after burner and scrubber. All federal,
state, and local environmental regulations must be observed.
2,2,4-トリメチルペンタン 上流と下流の製品情報
原材料
準備製品