PVA 88 - Polyvinyl Alcohol

About This Product

Polyvinyl alcohol with a degree of hydrolysis near 88 percent, CAS number 9002-89-5, is supplied as a white to cream granule or powder. It is made by polymerising vinyl acetate and then hydrolysing the acetate groups to hydroxyls, stopping short of completion. The residual acetate groups are the whole point of the grade. A fully hydrolysed chain is a regular sequence of hydroxyls that hydrogen-bond strongly to neighbouring chains, packing into crystalline regions that water cannot penetrate at room temperature. Leaving about one acetate in eight disrupts that regularity: the bulky acetate groups prevent close packing, crystallinity falls, and water can get between the chains, so the polymer dissolves in cold water. That single property determines its applications. It is the grade used for water-soluble film, including detergent pods and dissolvable laundry bags, for cold-mixed adhesives, and as a protective colloid in emulsion polymerisation, where its partly hydrophobic acetate segments anchor onto the growing polymer particle while the hydroxyl segments hold it in the water phase. It is used in water-soluble films and pods, emulsion polymerisation, adhesives, textile sizing, paper coating and as a thickener. Bio Green Chem supplies PVA 88 to specification on degree of hydrolysis, viscosity, ash, volatiles, pH and particle size.