PVOH

PVOH, or polyvinyl alcohol, is a synthetic, water-soluble polymer derived from vinyl acetate. It is commonly supplied as a powder, granules, or aqueous solution and is valued for its film-forming ability, clarity, and chemical resistance. The name PVOH is often used interchangeably with polyvinyl alcohol (PVA), though production methods and degree of hydrolysis distinguish grades used for different applications.

Production and properties

PVOH is produced by hydrolysis of polyvinyl acetate. The degree of hydrolysis and the polymer’s molecular weight determine solubility, viscosity, and mechanical properties. Highly hydrolyzed grades (near 98–99% hydrolysis) are typically water-soluble and form transparent, flexible films, whereas lower or partial hydrolysis yields grades with different solubility, swelling behavior, and strength. Molecular weight affects solution viscosity and the strength of films and binders. PVOH is generally non-toxic and compatible with water-based systems, making it suitable for coatings, binders, and thickeners.

Applications

PVOH serves as a versatile binder and film-former in papermaking, textiles, and coatings. It is used in water-based adhesives, including PVA glues, and as a binder for coatings and inks. In packaging, PVOH can be made into water-soluble films for dissolvable packaging and detergent sachets. It also finds use in hydrogels, pharmaceutical coatings, and various cosmetic and personal care formulations due to its film-forming and thickening properties. PVOH can act as an oxygen barrier in certain packaging applications and as a stabilizer or thickener in emulsions.

Safety and environment

PVOH is widely regarded as non-toxic and is used in food-contact and pharmaceutical-related applications under appropriate grades. Solubility in water means it requires proper handling to avoid unintended dissolution in process streams. Biodegradability varies with grade and environmental conditions, and some environments may see slower breakdown of certain PVOH forms.