propilen + hcl

From Wikipedia, the không tính tiền encyclopedia

Bạn đang xem: propilen + hcl

Propylene oxide
Structural formula
Ball-and-stick model of the propylene oxide molecule
Names
Preferred IUPAC name

(2R)-2-Methyloxirane
(2S)-2-Methyloxirane

Other names

Propylene oxide
Epoxypropane
Propylene epoxide
1,2-Propylene oxide
Methyl oxirane
1,2-Epoxypropane
Propene oxide
Methyl ethylene oxide
Methylethylene oxide

Identifiers

CAS Number

  • 75-56-9 check

3D model (JSmol)

  • Interactive image
ChEBI
  • CHEBI:38685 ☒
ChemSpider
  • 6138
ECHA InfoCard 100.000.800 Edit this at Wikidata
EC Number
  • 200-879-2
KEGG
  • C15508 ☒

PubChem CID

  • 6378
UNII
  • Y4Y7NYD4BK check

CompTox Dashboard (EPA)

  • DTXSID5021207 Edit this at Wikidata

InChI

  • InChI=1S/C3H6O/c1-3-2-4-3/h3H,2H2,1H3

    Key: GOOHAUXETOMSMM-UHFFFAOYSA-N

SMILES

  • CC1CO1

Properties

Chemical formula

C3H6O
Molar mass 58.080 g·mol−1
Appearance Colourless liquid
Odor benzene-like[1]
Density 0.859 g/cm3[2]
Melting point −111.9 °C (−169.4 °F; 161.2 K)[2]
Boiling point 35 °C (95 °F; 308 K)[2]

Solubility in water

41% (20 °C)[1]
Vapor pressure 445 mmHg (20 °C)[1]

Magnetic susceptibility (χ)

−4.25×10−5 cm3/mol[3]

Refractive index (nD)

1.3660[2]
Thermochemistry

Heat capacity (C)

120.4 J·(K·mol)−1

Std molar
entropy (S298)

196.5 J·(K·mol)−1

Std enthalpy of
formation fH298)

−123.0 kJ·mol−1[4]
Hazards
Occupational safety and health (OHS/OSH):

Main hazards

Extremely flammable[5][6]
GHS labelling:

Pictograms

GHS02: FlammableGHS08: Health hazardGHS07: Exclamation mark

Signal word

Danger
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may size explosive mixtures with water. E.g. white phosphorusSpecial hazards (white): no code

3

4

2

Flash point −37 °C (−35 °F; 236 K)

Autoignition
temperature

747 °C (1,377 °F; 1,020 K)
Explosive limits 2.3–36%[1]
Lethal dose or concentration (LD, LC):
660 mg/kg (guinea pig, oral)
380 mg/kg (rat, oral)
440 mg/kg (mouse, oral)
1140 mg/kg (rat, oral)
690 mg/kg (guinea pig, oral)[7]

LC50 (median concentration)

1740 ppm (mouse, 4 h)
4000 ppm (rat, 4 h)[7]

LCLo (lowest published)

2005 ppm (dog, 4 h)
4000 ppm (guinea pig, 4 h)[7]
NIOSH (US health exposure limits):

PEL (Permissible)

TWA 100 ppm (240 mg/m3)[1]

REL (Recommended)

Ca[1]

IDLH (Immediate danger)

Ca [400 ppm][1]

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

☒ verify (what is check☒ ?)

Infobox references

Propylene oxide is an acutely toxic and carcinogenic organic compound with the molecular formula CH3CHCH2O. This colourless volatile liquid with an odour similar to tướng ether, is produced on a large scale industrially. Its major application is its use for the production of polyether polyols for use in making polyurethane plastics. It is a chiral epoxide, although it is commonly used as a racemic mixture.

This compound is sometimes called 1,2-propylene oxide to tướng distinguish it from its isomer 1,3-propylene oxide, better known as oxetane.

Production[edit]

Industrial production of propylene oxide starts from propylene.[8] Two general approaches are employed, one involving hydrochlorination and the other involving oxidation.[9] In 2005, about half of the world production was through chlorohydrin technology and one half via oxidation routes. The latter approach is growing in importance.[10]

Hydrochlorination route[edit]

The traditional route proceeds via the conversion of propene to tướng propylene chlorohydrin according to tướng the following simplified scheme:

The mixture of 1-chloro-2-propanol and 2-chloro-1-propanol is then dehydrochlorinated. For example:

Lime (calcium hydroxide) is often used to tướng absorb the HCl.

Oxidation of propylene[edit]

The other general route to tướng propylene oxide involves oxidation of propylene with an organic peroxide. The reaction follows this stoichiometry:

CH3CH=CH2 + RO2H → CH3CHCH2O + ROH

The process is practiced with four hydroperoxides:[10]

  • In the Halcon process, t-Butyl hydroperoxide derived from oxygenation of isobutane, which affords t-butanol. This coproduct can be dehydrated to tướng isobutene, converted to tướng MTBE, an additive for gasoline.
  • Ethylbenzene hydroperoxide, derived from oxygenation of ethylbenzene, which affords 1-phenylethanol. This coproduct can be dehydrated to tướng give styrene, a useful monomer.
  • Cumene hydroperoxide derived from oxygenation of cumene (isopropylbenzene), which affords cumyl alcohol. Via dehydration and hydrogenation this coproduct can be recycled back to tướng cumene. This technology was commercialized by Sumitomo Chemical.[11]
  • Hydrogen peroxide is the oxidant in the hydrogen peroxide to tướng propylene oxide (HPPO) process, catalyzed by a titanium-doped silicalite:
    C3H6 + H2O2 → C3H6O + H2O

In principle, this process produces only water as a side product. In practice, some ring-opened derivatives of PO are generated.[12]

Reactions[edit]

Like other epoxides, PO undergoes ring-opening reactions. With water, propylene glycol is produced. With alcohols, reactions, called hydroxylpropylation, analogous to tướng ethoxylation occur. Grignard reagents add to tướng propylene oxide to tướng give secondary alcohols.

Some other reactions of propylene oxide include:[13]

  • Reaction with aluminium oxide at 250–260 °C leads to tướng propionaldehyde and a little acetone.
  • Reaction with silver(I) oxide leads to tướng acetic acid.
  • Reaction with sodium–mercury amalgam and water leads to tướng isopropanol.

Uses[edit]

Between 60 and 70% of all propylene oxide is converted to tướng polyether polyols by the process called alkoxylation.[14] These polyols are building blocks in the production of polyurethane plastics.[15] About 20% of propylene oxide is hydrolyzed into propylene glycol, via a process which is accelerated by acid or base catalysis. Other major products are polypropylene glycol, propylene glycol ethers, and propylene carbonate.

Niche uses[edit]

Fumigant[edit]

The United States Food and Drug Administration has approved the use of propylene oxide to tướng pasteurize raw almonds beginning on September 1, 2007, in response to tướng two incidents of contamination by Salmonella in commercial orchards, one incident occurring in Canada and one in the United States.[16][17] Pistachio nuts can also be subjected to tướng propylene oxide to tướng control Salmonella.

Microscopy[edit]

Propylene oxide is commonly used in the preparation of biological samples for electron microscopy, to tướng remove residual ethanol previously used for dehydration. In a typical procedure, the sample is first immersed in a mixture of equal volumes of ethanol and propylene oxide for 5 minutes, and then four times in pure oxide, 10 minutes each.

Munition[edit]

Propylene oxide is sometimes used in thermobaric munitions as the fuel in fuel–air explosives. In addition to tướng the explosive damage from the blast wave, unexploded propylene oxide can cause additional effects from direct toxicity.[18]

Safety[edit]

Propylene oxide is both acutely toxic and carcinogenic. Acute exposure causes respiratory tract irritation, eventually leading to tướng death [19]. Signs of toxicity after acute exposure include salivation, lacrimation, nasal discharge, gasping, lethargy and hypoactivity, weakness, and incoordination. Propylene oxide is also neurotoxic in rats, and presumably in humans [20]

Propylene oxide alkylates DNA.[21] As such, it is known animal carcinogen[22] and a potential human carcinogen, and is included into the List of IARC Group 2B carcinogens.[23]

Natural occurrence[edit]

In năm nhâm thìn it was reported that propylene oxide was detected in Sagittarius B2, a cloud of gas in the Milky Way weighing three million solar masses. It is the first chiral molecule to tướng be detected in space, albeit with no enantiomeric excess.[24]

Xem thêm: điphotpho pentaoxit

References[edit]

  1. ^ a b c d e f g NIOSH Pocket Guide to tướng Chemical Hazards. "#0538". National Institute for Occupational Safety and Health (NIOSH).
  2. ^ a b c d Haynes 2011, p. 3.384
  3. ^ Haynes 2011, p. 3.577
  4. ^ Haynes 2011, p. 5.24
  5. ^ "NFPA DIAMOND". www.otrain.com.
  6. ^ GOV, NOAA Office of Response and Restoration, US. "PROPYLENE OXIDE | CAMEO Chemicals | NOAA". cameochemicals.noaa.gov.
  7. ^ a b c "Propylene oxide". Immediately Dangerous to tướng Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  8. ^ Nijhuis TA, Makkee M, Moulijn JA, Weckhuysen BM (2006). "The Production of Propene Oxide: Catalytic Processes and Recent Developments". Industrial & Engineering Chemistry Research. 45 (10): 3447–3459. doi:10.1021/ie0513090. hdl:1874/20149.
  9. ^ Kahlich D, Wiechern U, Lindner J. "Propylene Oxide". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_239.
  10. ^ a b Nijhuis TA, Makkee M, Moulijn JA, Weckhuysen BM (2006). "The Production of Propene Oxide: Catalytic Processes and Recent Developments". Industrial & Engineering Chemistry Research. 45 (10): 3447. doi:10.1021/ie0513090. hdl:1874/20149.
  11. ^ "Summary of Sumitomo process from Nexant Reports". Archived from the original on 2006-01-17. Retrieved 2007-09-18.
  12. ^ Russo V, Tesser R, Santacesaria E, Di Serio M (2013). "Chemical and Technical Aspects of Propene Oxide Production via Hydrogen Peroxide (HPPO Process)". Industrial & Engineering Chemistry Research. 52 (3): 1168–1178. doi:10.1021/ie3023862.
  13. ^ Heilbron I, ed. (1953). Dictionary of Organic Compounds. Vol. 4. Oxford University Press. p. 249.
  14. ^ Adam N, Avar G, Blankenheim H, Friedrichs W, Giersig M, Weigang E, et al. "Polyurethanes". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a21_665.pub2.
  15. ^ "Usage of proplyene oxide". Dow Chemical. Archived from the original on 2007-09-15. Retrieved 2007-09-10.
  16. ^ "Guidance for Industry: Measures to tướng Address the Risk for Contamination by Salmonella Species in Food Containing a Pistachio-Derived Product As An Ingredient; Draft Guidance". fda.gov. June 2009. Archived from the original on 2011-02-09.
  17. ^ Agricultural Marketing Service, USDA (30 March 2007). "Almonds Grown in California; Outgoing Quality Control Requirements" (PDF). Federal Register. 72 (61): 15, 021–15, 036. Archived from the original (PDF) on 28 September 2007. Retrieved 2007-08-22.
  18. ^ "Backgrounder on Russian Fuel Air Explosives ("Vacuum Bombs") | Human Rights Watch". Hrw.org. February 1, 2000. Archived from the original on February 10, 2013. Retrieved April 23, 2013.
  19. ^ National Research Council (US) Committee on Acute Exposure Guideline Levels (2010). Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 9. National Academies Press.
  20. ^ Ohnishi A, Murai Y (February 1993). "Polyneuropathy due to tướng ethylene oxide, propylene oxide, and butylene oxide". Environmental Research. 60 (2): 242–247. doi:10.1006/enrs.1993.1032. PMID 8472653.
  21. ^ Lawley PD, Jarman M (February 1972). "Alkylation by propylene oxide of deoxyribonucleic acid, adenine, guanosine and deoxyguanylic acid". The Biochemical Journal. 126 (4): 893–900. doi:10.1042/bj1260893. PMC 1178497. PMID 5073240.
  22. ^ Ringo DL, Brennan EF, Cota-Robles EH (September 1982). "Epoxy resins are mutagenic: implications for electron microscopists". Journal of Ultrastructure Research. 80 (3): 280–287. doi:10.1016/s0022-5320(82)80041-5. PMID 6752439.
  23. ^ Grana R, Benowitz N, Glantz SA (May 2014). "E-cigarettes: a scientific review". Circulation. 129 (19): 1972–1986. doi:10.1161/circulationaha.114.007667. PMC 4018182. PMID 24821826.
  24. ^ "Scientists just detected this life-forming molecule in interstellar space for the first time". Science Alert. 2016-06-15.

Cited sources[edit]

  • Haynes WM, ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. ISBN 1-4398-5511-0.

External links[edit]

  • WebBook page for C3H6O
  • Propylene oxide at the United States Environmental Protection Agency
  • Propylene oxide – chemical product info: properties, production, applications.
  • Propylene oxide at the Technology Transfer Network Air Toxics Web Site
  • CDC – NIOSH Pocket Guide to tướng Chemical Hazards