Vinyl acetate monomer (VAM) is a colourless, volatile, flammable mobile liquid, with characteristic sweet etheral odour. Vinyl acetate is a dangerous fire and explosion hazard because it will polymerise violently when exposed to heat.
It is a key intermediate used in the making of a number of polymers and resins for adhesives, coatings, paints, films, textiles and other end-products.
The largest derivative is polyvinyl acetate (PVA) which is mainly used in adhesives as it has good adhesion properties to a number of substrates including paper, wood, plastic films and metals. Other uses for PVA include paper coatings, paints and industrial coatings.
The second largest consumer of VAM is polyvinyl alcohol (PVOH) which is manufactured from PVA.
VAM is consumed in the manufacture of ethylene vinyl acetate (EVA) and vinyl acetate ethylene (VAE).
A fast growing use of VAM is the manufacture of ethylene vinyl alcohol (EVOH) which is used as a barrier resin in food packaging, plastic bottles and gasoline tanks, and in engineering polymers.
Other VAM derivatives include vinyl chloride-vinyl acetate copolymers which have major applications in coatings, paints and adhesives.
VAM is usually produced by the catalysed, vapour phase reaction of acetic acid with ethylene and oxygen in a fixed bed tubular reactor using a supported noble metal catalyst. The VAM is recovered by condensation and scrubbing and purified by distillation.