Vinyl acetate

Vinyl acetate
Names
Preferred IUPAC name
Ethenyl acetate
Systematic IUPAC name
Ethenyl ethanoate
Other names
  • Acetic acid vinyl ester
  • Vinyl ethanoate
  • Acetoxyethene
  • VyAc
  • VAM
  • Vinyl acetate monomer
  • Acetic acid ethenyl ester
  • 1-Acetoxyethylene
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.003.224
EC Number 203-545-4
KEGG
MeSH C011566
UNII
Properties
C4H6O2
Molar mass 86.09 g·mol−1
Appearance Colorless liquid
Odor Sweet, pleasant, fruity; may be sharp and irritating[1]
Density 0.934 g/cm3
Melting point −93.5 °C (−136.3 °F; 179.7 K)
Boiling point 72.7 °C (162.9 °F; 345.8 K)
-46.4·10−6 cm3/mol
Hazards
Safety data sheet ICSC 0347
R-phrases (outdated) R11
S-phrases (outdated) S16, S23, S29, S33
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasolineHealth code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroformReactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g., phosphorusSpecial hazards (white): no codeNFPA 704 four-colored diamond
3
2
2
Flash point −8 °C (18 °F; 265 K)
427 °C (801 °F; 700 K)
Explosive limits 2.6–13.40%
US health exposure limits (NIOSH):
PEL (Permissible)
 none[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Vinyl acetate is an organic compound with the formula CH3CO2CH=CH2. This colorless liquid is the precursor to polyvinyl acetate, an important industrial polymer.[3]

Production

The worldwide production capacity of vinyl acetate was estimated at 6,154,000 tonnes/year in 2007, with most capacity concentrated in the United States (1,585,000 all in Texas), China (1,261,000), Japan (725,000) and Taiwan (650,000).[4] The average list price for 2008 was $1600/tonne. Celanese is the largest producer (ca 25% of the worldwide capacity), while other significant producers include China Petrochemical Corporation (7%), Chang Chun Group (6%), and LyondellBasell (5%).[4]

It is a key ingredient in furniture glue.[5]

Preparation

Vinyl acetate is the acetate ester of vinyl alcohol. Since vinyl alcohol is highly unstable (with respect to acetaldehyde), the preparation of vinyl acetate is more complex than the synthesis of other acetate esters.

The major industrial route involves the reaction of ethylene and acetic acid with oxygen in the presence of a palladium catalyst.[6]

2 C2H4 + 2 CH3CO2H + O2 → 2 CH3CO2CHCH2 + 2 H2O

The main side reaction is the combustion of organic precursors.

Mechanism

Isotope labeling and kinetics experiments suggest that the mechanism involves PdCH2CH2OAc-containing intermediates. Beta-hydride elimination would generate vinyl acetate and a palladium hydride, which would be oxidized to give hydroxide.[7]

Alternative routes

Vinyl acetate was once prepared by hydroesterification. This method involves the gas-phase addition of acetic acid to acetylene in the presence of metal catalysts. By this route, using mercury(II) catalysts, vinyl acetate was first prepared by Fritz Klatte in 1912.[3] Another route to vinyl acetate involves thermal decomposition of ethylidene diacetate:

(CH3CO2)2CHCH3 → CH3CO2CHCH2 + CH3CO2H

Polymerization

It can be polymerized to give polyvinyl acetate (PVA). With other monomers it can be used to prepare various copolymers such as ethylene-vinyl acetate (EVA), vinyl acetate-acrylic acid (VA/AA), polyvinyl chloride acetate (PVCA), and polyvinylpyrrolidone (Vp/Va Copolymer, used in hair gels).[8] Due to the instability of the radical, attempts to control the polymerization via most 'living/controlled' radical processes have proved problematic. However, RAFT (or more specifically MADIX) polymerization offers a convenient method of controlling the synthesis of PVA by the addition of a xanthate or a dithiocarbamate chain transfer agent.

Other reactions

Vinyl acetate undergoes many of the reactions anticipated for an alkene and an ester. Bromine adds to give the dibromide. Hydrogen halides add to give 1-haloethyl acetates, which cannot be generated by other methods because of the non-availability of the corresponding halo-alcohols. Acetic acid adds in the presence of palladium catalysts to give ethylidene diacetate, CH3CH(OAc)2. It undergoes transesterification with a variety of carboxylic acids.[9] The alkene also undergoes Diels-Alder and 2+2 cycloadditions.

Toxicity evaluation

Tests suggest that vinyl acetate is of low toxicity. For rats (oral) LD50 is 2920 mg/kg.[3]

On January 31, 2009, the Government of Canada's final assessment concluded that exposure to vinyl acetate is not harmful to human health.[10] This decision under the Canadian Environmental Protection Act (CEPA) was based on new information received during the public comment period, as well as more recent information from the risk assessment conducted by the European Union.

It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.[11]

See also

References

  1. ↑ "Public Health Statement for Vinyl Acetate". Agency for Toxic Substances and Disease Registry, Centers for Disease Control. It has a sweet, pleasant, fruity smell, but the odor may be sharp and irritating to some people.
  2. ↑ "NIOSH Pocket Guide to Chemical Hazards #0656". National Institute for Occupational Safety and Health (NIOSH).
  3. 1 2 3 G. Roscher (2007). "Vinyl Esters". Ullmann's Encyclopedia of Chemical Technology. Weinheim: Wiley-VCH. doi:10.1002/14356007.a27_419.
  4. 1 2 H. Chinn (September 2008). "CEH Marketing Research Report: Vinyl Acetate". Chemical Economics Handbook. SRI consulting. Retrieved July 2011. Check date values in: |accessdate= (help)
  5. ↑ Karl Shmavonian (2012-10-24). "Madhukar Parekh's Pidilite Industries Earns His Family $1.36 Billion". Forbes.com. Retrieved 27 January 2013. though Pidilite has had to contend with the rising price of vinyl acetate monomer, its key raw material
  6. ↑ Y.-F. Han; D. Kumar; C. Sivadinarayana & D.W. Goodman (2004). "Kinetics of ethylene combustion in the synthesis of vinyl acetate over a Pd/SiO2 catalyst" (PDF). Journal of Catalysis. 224: 60–68. doi:10.1016/j.jcat.2004.02.028.
  7. ↑ Stacchiola, D.; Calaza, F.; Burkholder, L.; Schwabacher Alan, W.; Neurock, M.; Tysoe Wilfred, T., (2005). "Elucidation of the Reaction Mechanism for the Palladium‐Catalyzed Synthesis of Vinyl Acetate". Angewandte Chemie International Edition. 44: 4572–4574. doi:10.1002/anie.200500782.
  8. ↑ "VP/VA Copolymer". Personal Care Products Council. Retrieved 13 December 2012.
  9. ↑ D. Swern & E. F. Jordan, Jr. (1963). "Vinyl Laurate and Other Vinyl Esters" (PDF). Organic Syntheses, Collected Volume 4: 977. Archived from the original (PDF) on 2011-06-05. Retrieved 2007-11-11.
  10. ↑ http://www.ec.gc.ca/ese-ees/59EC93F6-2C5D-42B4-BB09-EB198C44788D/batch2_108-05-4_pc_en.pdf
  11. ↑ "40 C.F.R: Appendix A to Part 355—The List of Extremely Hazardous Substances and Their Threshold Planning Quantities" (PDF). Code of Federal Regulations (December 2017 ed.). Government Printing Office. title 40, vol 30, part 355, app A (EPA): 474. December 2017. Retrieved 7 March 2018 – via US GPO.
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