Vinyl acetate

Vinyl acetate
IUPAC name	Ethenyl acetate
Systematic name	Ethenyl ethanoate
Other names	Acetic acid vinyl ester, acetoxyethene, VyAc, VAM, zeset T, VAM vinyl acetate monomer, acetic acid ethenyl ester, 1-acetoxyethylene
Identifiers
CAS number	108-05-4 Y
PubChem	7904
SMILES	C=COC(C)=O
Properties
Molecular formula	C4H6O2
Molar mass	86.09 g/mol
Appearance	Colorless liquid
Density	0.934 g/cm3
Melting point	-93 °C, 180 K, -135 °F
Boiling point	72.7 °C, 346 K, 163 °F
Hazards
MSDS	ICSC 0347
R-phrases	R11
S-phrases	S16, S23, S29, S33
NFPA 704	3 2 2
Flash point	-8°C
Autoignition temperature	427 °C
Explosive limits	2.6–13.40%
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Vinyl acetate is an organic compound with the formula CH₃COOCH=CH₂. A colorless liquid with a pungent odor, it is the precursor to polyvinyl acetate, an important polymer in industry.

Preparation

The major industrial route involves the reaction of ethylene and acetic acid with oxygen in the presence of a palladium catalyst.^[1]

Ethylene + acetic acid + 1/2 O₂ → Vinyl acetate + H₂O

But byproducts are also generated:

Ethylene + 3 O₂ → 2 CO₂ + 2 H₂O

Vinyl acetate is also prepared by the gas-phase addition of acetic acid to acetylene.^[2]

Polymerization

It can be polymerized, either by itself to make polyvinyl acetate or with other monomers to prepare copolymers such as ethylene-vinyl acetate. 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 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 generate 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.^[3] The alkene also undergoes Diels-Alder and 2+2 cycloadditions.

Possible label as "toxic" in Canada

Due to research done by the International Agency for Research on Cancer that the substance could be linked to cancer in lab rats, a draft report due from the Government of Canada may label it toxic, along with as many as sixteen other substances.^[4]

References

1. ^ Y.-F. Han, D. Kumar, C. Sivadinarayana, and D.W. Goodman (2004). "Kinetics of ethylene combustion in the synthesis of vinyl acetate over a Pd/SiO2 catalyst". Journal of Catalysis 224: 60–68. doi:10.1016/j.jcat.2004.02.028. http://www.chem.tamu.edu/rgroup/goodman/pdf%20files/442_joc-224-04-60.pdf. 
2. ^ G. Roscher "Vinyl Esters" in Ullmann’s Encyclopedia of Chemical Technology, 2007 John Wiley & Sons: New York.
3. ^ D. Swern and E. F. Jordan, Jr (1963). "Vinyl Laurate and Other Vinyl Esters". Organic Syntheses, Collected Volume 4: 977. http://www.orgsyn.org/orgsyn/pdfs/CV4P0977.pdf. 
4. ^ "Chewing gum substance could be toxic". Vancouver Sun. 2008-05-13. p. A4. 

External links

• EPA health assessment information on vinyl acetate