Polyvinyl alcohol is a polymer made from vinyl acetate monomers. It is a white granular powder, has no odor and toxic properties. This component also is known as PVOH and PVAL that dissolves in water, slightly soluble in ethanol, and insoluble in other organic solvents.
This component produced by Hermann and Haehnel in 1924. They hydrolyzed polyvinyl acetate (PVAc) in the presence of ethanol and potassium hydroxide. Polyvinyl alcohol molecular formula is 44.053 g/mol and has a boiling point at 644oF at 760 mmHg and a melting point at 442oF. Typically, a 5% PVA solution has a PH between 5.0 and 6.5. It is used for packaging in the food industry, moisture barrier, in sizing (coating with a substance like, gelatinous to reduce moisture or oxygen absorbency) agent, and in freshwater sports fishing. In the following, we will continue to review its properties and other applications.
Chemical and physical properties of Polyvinyl alcohol
As we mentioned earlier, PVA is made of polyvinyl acetate monomer, which means the key raw material for PVA is PVAc. PVAc monomer forms from the polymerization of vinyl acetate. After partial hydrolysis of this material, ester groups in PVAc will be exchanged with a hydroxyl group in presence of an alkaline catalyst such as solution sodium hydroxide. Then aqueous saponification agent should be added gradually. Finally, PVA will be precipitate and should wash and dry. Shanghai Chemex is one of the most reputable manufacturers of this chemical in the world.
Applications of Polyvinyl alcohol:
About this chemical consumption in the world, we should say that has been used 41% as a resin in the fishing and textile industry; 22% in adhesives; 18% in the polymerization of vinyl chloride; 9% as the pigment binder, and 10% in other applications.
PVA is widely used in sizing, packaging, pharmaceutical market, and strength textile, like sodium diacetate. It is used even in some sports such as freshwater sports fishing. This component attaches to the hook and lands on the bottom of the water. It breaks down there because is soluble in water. This attracts fish to the hood and fishes are trapped in this way. Food packaging is one of the most applications of PVA (31.4% of the global market of this component in 2016). Its mechanism is that forms a thin film on the surface that is water-resist.
Polyvinyl alcohol Global Market:
In general, Asia Pacific has the biggest market for this component in the world. In Asia Pacific market is projected to grow at a CAGR of 5.5% from 2017 to 2025. The U.S market is anticipated to grow at a CAGR of 5.4% in the forecast period.