1,1-Dichloroethene

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1,1-Dichloroethene
Structural formula
Ball-and-stick model
Names
IUPAC name
1,1-Dichloroethene
Other names
1,1-Dichloroethylene
1,1-DCE
vinylidene chloride
vinylidene dichloride
Identifiers
75-35-4 YesY
ChEBI CHEBI:34031 N
ChemSpider 6126 YesY
Jmol-3D images Image
KEGG C14039 YesY
PubChem 6366
UNII 21SK105J9D YesY
Properties
C2H2Cl2
Molar mass 96.94 g/mol
Density 1.213 g/cm3
Melting point −122 °C (−188 °F; 151 K)
Boiling point 32 °C (90 °F; 305 K)
0.04% (20°C)[1]
Vapor pressure 500 mmHg (20°C)[1]
1.3 D
Structure
C2v
Planar
Hazards
NFPA 704
Flammability code 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., propane Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g., phosphorus Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point −22.8 °C (−9.0 °F; 250.3 K)
Explosive limits 6.5%-15.5%[1]
Lethal dose or concentration (LD, LC):
16,000 ppm (rat, 4 hr)
17,300 ppm (mouse, 2 hr)
16,000 ppm (rat, 8 hr)[2]
US health exposure limits (NIOSH):
none[1]
Ca[1]
Ca [N.D.][1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 N verify (what isYesY/N?)
Infobox references

1,1-Dichloroethene, commonly called 1,1-dichloroethylene or 1,1-DCE, is an organochloride with the molecular formula C2H2Cl2. It is a colorless liquid with a sharp odor. Like most chlorocarbons, it is poorly soluble in water, but soluble in organic solvents. 1,1-DCE was the precursor to the original cling-wrap for food, but this application has been phased out.

Production[edit]

1,1-DCE is produced by dehydrochlorination of 1,1,2-trichloroethane, a relatively unwanted byproduct in the production of 1,1,1-trichloroethane and 1,2-dichloroethane. The conversion involves a base-catalyzed reaction:

Cl2CHCH2Cl + NaOH → Cl2C=CH2 + NaCl + H2O

The gas phase reaction, without the base, would be more desirable but is less selective.[3]

Applications[edit]

1,1-DCE is mainly used as a comonomer in the polymerization of vinyl chloride, acrylonitrile, and acrylates. It is also used in semiconductor device fabrication for growing high purity silicon dioxide (SiO2) films.

Polyvinylidene chloride[edit]

As with many other alkenes, 1,1-DCE can be polymerised to form polyvinylidene chloride. A very widely used product, cling wrap, or Saran was made from this polymer. During the 1990s research suggested that, in common with many chlorinated carbon compounds, Saran posed a possible danger to health by leaching, especially on exposure to food in microwave ovens. Since 2004, therefore cling wrap's formulation has changed to a form of polyethylene.

Safety[edit]

The health effects from exposure to 1,1-DCE are primarily on the central nervous system, including symptoms of sedation, inebriation, convulsions, spasms, and unconsciousness at high concentrations.[4] 1,1-DCE is considered a potential occupational carcinogen by the National Institute for Occupational Safety and Health .[5]

See also[edit]

References[edit]

  1. ^ a b c d e f "NIOSH Pocket Guide to Chemical Hazards #0661". National Institute for Occupational Safety and Health (NIOSH). 
  2. ^ "1,1-Dichloroethane". Immediately Dangerous to Life and Health. National Institute for Occupational Safety and Health (NIOSH). 
  3. ^ Manfred Rossberg, Wilhelm Lendle, Gerhard Pfleiderer, Adolf Tögel, Eberhard-Ludwig Dreher, Ernst Langer, Heinz Rassaerts, Peter Kleinschmidt, Heinz Strack, Richard Cook, Uwe Beck, Karl-August Lipper, Theodore R. Torkelson, Eckhard Löser, Klaus K. Beutel, Trevor Mann "Chlorinated Hydrocarbons" in Ullmann's Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim. doi:10.1002/14356007.a06_233.pub2.
  4. ^ epa.gov
  5. ^ CDC - NIOSH Pocket Guide to Chemical Hazards

External links[edit]