Polyvinyl alcohol – artificial water synthetic thermoplastic polymer. Synthesis of polyvinyl alcohol is exchange reaction of alkaline hydrolysis or alcoholysis.
The German chemists Willie Hermann and Volfram Gonel in 1924 were pioneers of polyvinyl alcohol.
Unlike many vinyl polymers receiving polyvinyl alcohol does not happen by polymerization of the corresponding monomers. Monomer of polyvinyl alcohol exists only in the form of a tautomeric form steady acetic aldehyde. Receiving polyvinyl alcohol happens by partial or full hydrolysis of polyvinyl acetate to remove etilatsetatovy groups.
Industrial ways of receiving polyvinyl alcohol are various options of saponification of polyvinyl alcohol in the water or spirit environment in the presence of acids and the bases.
In 2002 under the leadership of Kuznetsov A. A. the laboratory of the ISPM heat-resistant thermolayers of Enikolopov in Moscow developed the gel-free way of receiving polyvinyl alcohol having a number of advantages in comparison with other ways, such as low cost, high efficiency and short-term synthesis.
The film-forming, emulsifying and sticking together properties of polyvinyl alcohol allow to use it in various industries and spheres. Polyvinyl alcohol is steady against influence of oils, fats and solvents. It has no smell and is non-toxical, has high durability on stretching and flexibility, and also has the high content of oxygen.
However, these properties of polyvinyl alcohol are in direct dependence on humidity at which increase it absorbs water. Water which works as the plasticizer reduces durability of polyvinyl alcohol. It completely breaks up and is quickly dissolved in it.
Molecular formula of polyvinyl alcohol – C2H4Ox, density – from 1,19 to 1,31 g/cm ³, melting temperature – 200 °C, boiling temperature – 228 °C.
Polyvinyl alcohol is raw materials for production of other polymers, such as:
Use of polyvinyl alcohol as a thickener and the modifier in polyvinyl acetate glues is also known.
Use of polyvinyl alcohol as the stabilizer of emulsion polymerization and protective colloid for production of polyvinyl acetate dispersions is widely widespread in China.
In the textile industry of Japan and North Korea use of polyvinyl alcohol is widely widespread in production of fiber.
Polyvinyl alcohol found application in various industries and spheres in quality:
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