Vinyl acetate
Encyclopedia
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.
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%).
and acetic acid
with oxygen
in the presence of a palladium
catalyst.
But byproducts are also generated:
Vinyl acetate is also prepared by the gas-phase addition of acetic acid to acetylene
.
s to prepare copolymers such as ethylene-vinyl acetate
(EVA), vinyl acetate-acrylic acid
(VA/AA) and polyvinyl chloride acetate
(PVCA). 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.
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 acid
s. The alkene also undergoes Diels-Alder and 2+2 cycloadditions.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
CH3COOCH=CH2. A colorless liquid with a pungent odor, it is the precursor to polyvinyl acetate
Polyvinyl acetate
Polyvinyl acetate, PVA, PVAc, poly, is a rubbery synthetic polymer with the formula n. It belongs to the polyvinyl esters family with the general formula -[RCOOCHCH2]-...
, an important polymer in industry.
Production
The worldwide production capacity of vinyl acetate monomer (VAM) was estimated at 6,154,000 tonnes/annum 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). The average list price for 2008 was $1600/tonne. CelaneseCelanese
Celanese Corporation is a Fortune 500 global technology and specialty materials company with its headquarters in Dallas, Texas. The company is a leading producer of acetyl products, which are intermediate chemicals for nearly all major industries, and is the world's largest producer of vinyl...
is the largest producer (ca 25% of the worldwide capacity), while other significant producers include China Petrochemical Corporation
China Petrochemical Corporation
China Petrochemical Corporation or Sinopec Group is Asia's largest oil refining and petrochemical enterprise, administered by SASAC for the State Council of the People's Republic of China...
(7%), Chang Chun Group (6%) and LyondellBasell (5%).
Preparation
The major industrial route involves the reaction of ethyleneEthylene
Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...
and acetic acid
Acetic acid
Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...
with oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
in the presence of a palladium
Palladium
Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired...
catalyst.
- 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
Acetylene
Acetylene is the chemical compound with the formula C2H2. It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in pure form and thus is usually handled as a solution.As an alkyne, acetylene is unsaturated because...
.
Polymerization
It can be polymerized, either by itself to make polyvinyl acetate or with other monomerMonomer
A monomer is an atom or a small molecule that may bind chemically to other monomers to form a polymer; the term "monomeric protein" may also be used to describe one of the proteins making up a multiprotein complex...
s to prepare copolymers such as ethylene-vinyl acetate
Ethylene-vinyl acetate
Ethylene vinyl acetate is the copolymer of ethylene and vinyl acetate. The weight percent vinyl acetate usually varies from 10 to 40%, with the remainder being ethylene....
(EVA), vinyl acetate-acrylic acid
Acrylic acid
Acrylic acid is an organic compound with the formula CH2=CHCO2H. It is the simplest unsaturated carboxylic acid, consisting of a vinyl group connected directly to a carboxylic acid terminus. This colorless liquid has a characteristic acrid or tart smell. It is miscible with water, alcohols,...
(VA/AA) and polyvinyl chloride acetate
Polyvinyl chloride acetate
Polyvinyl chloride acetate is a thermoplastic copolymer of vinyl chloride and vinyl acetate. It is used in the manufacture of electrical insulation, of protective coverings , and of credit cards and swipe cards....
(PVCA). Due to the instability of the radical, attempts to control the polymerization via most 'living/controlled' radical processes have proved problematic. However, RAFT
RAFT (chemistry)
Reversible Addition-Fragmentation chain Transfer or RAFT polymerization is one kind of controlled radical polymerization. Discovered at the Commonwealth Scientific and Industrial Research Organisation in 1998, RAFT polymerization is a relatively new method for the synthesis of living radical...
(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 alkeneAlkene
In organic chemistry, an alkene, olefin, or olefine is an unsaturated chemical compound containing at least one carbon-to-carbon double bond...
and an ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
. Bromine
Bromine
Bromine ") is a chemical element with the symbol Br, an atomic number of 35, and an atomic mass of 79.904. It is in the halogen element group. The element was isolated independently by two chemists, Carl Jacob Löwig and Antoine Jerome Balard, in 1825–1826...
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 acid
Carboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...
s. The alkene also undergoes Diels-Alder and 2+2 cycloadditions.