Polyvinyl Alcohol PVA is composed of Vinyl Acetate and obtained by alcoholysis reaction, polymerization. It is a kind of white, powdery, stable, non-toxic and water soluble high molecular polymer. It can be quickly dissolved in water at the room temperature, and forming a stable colloid. Water is a good solvent of Polyvinyl Alcohol. Polyvinyl Alcohol PVA has a good film-making property. And the film has excellent adhesion, solvent resistance, friction resistance, strength with oxygen denial of access. Polyvinyl Alcohol has both hydrophobic and hydrophilic functional groups, so that Polyvinyl Alcohol PVA is a surfactant substances. And Polyvinyl Alcohol PVA can be used as the protective colloid of polymer emulsion and suspended polymerization.
Physical properties:
Solubility: Polyvinyl Alcohol PVA powder can dissolves in water at room temperature.
Thermal stability: Polyvinyl Alcohol PVA will softem when heated at 40 ℃ and with no significant change. When the temperature is more than 160 ℃, prolonged heating will gradually coloring. When the temperature is more than 220 ℃, it will occur decomposition, and generation water, acetic aicd, acetaldehyde and crotonaldehyde.
Chemical resistance: PVA is hardly under the influence of weak acid, week alkali or organic solvents, the oil resistance of it is very high.
Film: PVA film formation, formed film is colorless transparent, has good mechanical strength.
Chemical properties:
PVA can be thought of as a liner polymer with secondary hydroxyl.