Elvanol 90-50 Polyvinyl alcohol DuPont Vinyl >> Polyvinyl Alcohol (PVOH) Architectural / Decorative Other industry >> Paper coatings Insoluble in water, cold Soluble in water, hot DuPont Elvanol® polyvinyl alcohol (PVOH, sometimes also referred to as PVA) is a water-soluble synthetic polymer with excellent film-forming, emulsifying, and adhesive properties. This versatile polymer offers outstanding resistance to oil, grease and solvents, plus high tensile strength, flexibility, and high oxygen barrier. DuPont markets three types of Elvanol®: fully hydrolyzed, partially hydrolyzed, and copolymers. All are made by alcoholysis of polyvinyl acetate (PVAc). The fully hydrolyzed grades contain few, if any, residual acetate groups; while partially hydrolyzed grades retain some of the residual acetate groups. The partially hydrolyzed grades dissolve in water at room temperature; fully hydrolyzed grades dissolve in hot (200 degree F) water, and remain in solution when cooled to room temperature. Elvanol® 90-50 is a fully hydrolyzed polyvinyl alcohol (PVOH) designed to provide high film strength and binding power in relatively low-viscosity systems. Table 1 lists typical resin properties. This polyvinyl alcohol provides tensile and adhesive strength approaching that of the medium viscosity, fully hydrolyzed commercial grade, Elvanol® 71-30. Like Elvanol® 71-30, Elvanol® 90-50 is resistant to cold water, but dissolves readily on heating to 90°C (194°F) or above with good agitation. However, Elvanol® 90-50 permits higher solids solutions at a given viscosity and temperature, or lower solution viscosities at the same solids content and temperature as compared with Elvanol® 71-30. Elvanol® 90-50 is suggested for evaluation wherever the high film strength and oil, grease, and solvent resistance associated with higher viscosity, fully hydrolyzed polyvinyl alcohols are desired, but a lower solution viscosity is needed. For example, it should be useful in such applications as paper coating and sizing, adhesives for porous substrates including paper and paperboard, hot-water-soluble film, and as a binder for pigments or other solid particles. Elvanol® 90-50 is particularly useful as a pigment binder for ceiling tile primers. Fully hydrolyzed polyvinyl alcohol. Used in paper coating and as a pigment binder for ceiling tile primers. Provides high film strength and binding power in relatively low-viscosity systems. Gives resistance to cold water. Offers very good film-forming, emulsifying, and adhesive properties., outstanding resistance to oil, grease and solvents, high tensile strength, flexibility, and high oxygen barrier.