PVA

PVA is an acronym used for several vinyl-based polymers, with polyvinyl alcohol (PVOH) and polyvinyl acetate (PVAc) being the two most common. In everyday usage, PVA can refer to either material or the family of related polymers, which can lead to confusion because they have different properties and applications. PVA glue sold for craft use typically refers to PVAc.

Polyvinyl alcohol is produced by the hydrolysis of polyvinyl acetate, giving a water-soluble synthetic polymer. It forms clear, flexible films with good gas barrier properties and high tensile strength. The solubility and film characteristics depend on the degree of hydrolysis and molecular weight. PVOH is generally non-toxic and is used in papermaking as a sizing agent, in textile sizing, coatings, and adhesives. It also appears in certain coatings, cosmetics, pharmaceutical excipients, and stabilizers for contact lens solutions. Environmental degradation of PVOH depends on conditions such as microbial activity and temperature.

Polyvinyl acetate is a thermoplastic polymer prepared by polymerizing vinyl acetate monomer. It is typically processed as an aqueous latex emulsion and forms insoluble, flexible films upon drying. PVAc is widely used as a binder in paints and coatings, as a primary component of many white wood glues and paper glues, and as a component in packaging adhesives. It provides good adhesion, clarity, and flexibility, especially when combined with plasticizers or other polymers. PVAc is commonly used in coatings for paper, textiles, and wood products, and as an additive in latex paints.

Both polymers are important in industry and consumer products. PVAc is often encountered as PVA glue, while PVOH refers to the water-soluble film-forming polymer used in various technical and consumer applications.