Polyvinyl alcohol is an artificial polymer that is readily soluble in water. It was obtained in 1924 by two chemical scientists - Gonel and German - using the saponification reaction.
Physical properties
Polyvinyl alcohol is a white powder with the ability to form a film. This polymer is very strong and flexible, but since these qualities depend on moisture (it absorbs liquid), the tensile strength decreases, and with a certain degree of humidity, a lot of plasticity appears. It has hygroscopic properties, it is easily soluble (mainly in water). In organic solvents such as fats and oils, it is not able to dissolve. When used, this substance does not have a toxic effect, which means it can be considered harmless.
Alcohol production
Polyvinyl alcohol or PVA is obtained from polyvinyl acetate by hydrolysis or alcoholysis and is produced in the form of granules or powder. Upon receipt of the PVA, a variety of technological methods are used, from simple to quite complex and time-consuming.
Polyvinyl alcohol - application
PVA is widely used today. It can play the role of a thickener in the manufacture of glue and shampoos, with its help produce latex material. It has been successfully used by restorers to restore artistic paintings. Due to its hygroscopicity, it has found wide application in the creation of hygiene products. All kinds of diapers, tampons and pads are made using PVA. Polyvinyl alcohol and food manufacturers have not forgotten. It is used as an emulsifier in the manufacture of mayonnaise, sauces, ketchups and other food products, and is also used as an amplifier for the taste of confectionery.
Modern medicine has also adopted some of the properties of PVA. It is used in the manufacture of certain medications, after having subjected it to thorough purification from impurities. Ophthalmologists use polyvinyl alcohol for the preparation of eye drops and as a lubricant for contact lenses. Even oncologists have found the use of PVA in the treatment of cancer. In particular, it is necessary for performing a non-surgical embolization procedure. And this is not the whole range of applications of polyvinyl alcohol in medicine.
In the textile industry, PVA is used to remove static electricity, and in the paper industry - for the 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 paints and varnishes. All plants producing artificial fibers use PVA for their manufacture, which gives them strength through the process of sizing the threads.
Even a science such as microbiology began to use PVA in the process of immobilization of enzymes and cells. Polyvinyl alcohol has also been used in printing, in particular in silk-screen printing. In this area, it is used as a polymer layer for the copy process. It can also be used as a packaging or protective material in production for coating parts, due to the fact that the PVA layer is easily removed.
Enterprises that manufacture and use molds have also successfully used this polymer. Today, PVA is becoming more widespread in the national economy. It is affordable, easily transported (usually in plastic bags packed in paper bags) in closed transport to avoid getting wet. Since polyvinyl alcohol is flammable, it is necessary to comply with safety rules when storing and loading-unloading.