Polyvinyl alcohol is an artificial polymer that dissolves easily in water. It was obtained in 1924 by two chemists, Gonel and Herman, using a saponification reaction.
Physical properties
Polyvinyl alcohol is a white powder,having the ability to form a film. This polymer is very strong and flexible, but since these qualities depend on humidity (it absorbs the liquid), the tensile strength decreases, and at a certain degree of humidity, greater plasticity appears. It has hygroscopic properties, easily dissolves (mainly in water). In organic solvents such as fats and oils, it is not able to dissolve. When used, this substance does not have toxic effects, which means it can be considered harmless.
Getting alcohol
Polyvinyl alcohol or PVA is obtained frompolyvinyl acetate by hydrolysis or alcoholysis and is produced in the form of granules or powder. When receiving PVS, a variety of technological methods are used, from simple to fairly complex and time-consuming.
Polyvinyl alcohol - application
PVS is used widely today.It can play the role of thickener in the manufacture of glue and shampoos, with its help produce latex material. It is successfully used by restorers to restore art paintings. Due to its hygroscopicity, it has found wide application in the creation of hygiene products. All kinds of diapers, tampons and gaskets are made with the help of PVS. Do not forget polyvinyl alcohol and food manufacturers. It is used as an emulsifier for the production of mayonnaises, sauces, ketchups and other food products, and is also used as an enhancer for the taste of confectionery.
Modern medicine is also usedsome properties of PVA. It is used in the manufacture of certain medications, subjecting it to thorough cleaning of impurities. Ophthalmologists use polyvinyl alcohol to prepare eye drops and as a lubricant for contact lenses. Even oncologists have found the use of PVS in the treatment of cancer. In particular, it is necessary for performing a non-surgical procedure of embolization. And this is not the whole range of polyvinyl alcohol in medicine.
In the textile industry, PVA is used forremoval of static electricity, and in paper - for recycling of waste paper. In addition, it is an indispensable component in the production of pulp. Polyvinyl alcohol is necessary for builders and metallurgists, tanners and manufacturers of paint and varnish products. All the factories producing artificial fibers use for their manufacture PVA, which gives them strength by means of the sizing process of the yarns.
Even such a science as microbiology has becomeuse PVA in the process of immobilization of enzymes and cells. Polyvinyl alcohol was also used in printing, in particular, in silk-screen printing. In this area it is used as a polymer layer for the copying process. It can also be used as a packaging or protective material in the production to cover parts, thanks to the fact that the PVA layer is easily removed.
Enterprises manufacturing and applyingmolds, also use this polymer successfully. Today, PVS is becoming increasingly widespread in the national economy. It is affordable, easily transported (usually in plastic bags packed in paper bags) in closed transport to avoid wetting. Since polyvinyl alcohol is flammable, it is necessary to comply with safety regulations when storing and loading / unloading it.
