Celvol 502 Polyvinyl alcohol 25213-24-5 Celanese Polyvinyl alcohol (PVOH) ADHESIVE Celvol polyvinyl alcohol combines high tensile strength with ease of film formation. Additionally, Celvol resins show excellent adhesive and bonding characteristics. Partially hydrolyzed grades have better adhesion to hydrophobic surfaces. The degree of hydrolysis affects the water sensitivity of both the resin and film. Water resistance increases with increasing hydrolysis. The super hydrolyzed grades should be used when maximum water resistance and humidity resistance are desired. Celvol polyvinyl alcohol resins are generally unaffected by greases, petroleum hydrocarbons and animal or vegetable oils. Resistance to organic solvents increases with the degree of hydrolysis. Celvol polyvinyl alcohol film can be plasticized with glycerol or the lower molecular weight glycols. These materials generally act as humectants, holding water in the film. Polyvinyl alcohol adheres particularly well to cellulosic substrates such as paper and wood. Adding it to a polyvinyl acetate emulsion will increase the efficiency as well as the tensile strength of the resulting adhesive. Wood—High Performance. Partially hydrolyzed grades are recommended for penetration into the wood and devel-opment of fiber tear. Polyvinyl alcohol imparts strength and heat resistance to the bond. Lower-molecular-weight partially hydrolyzed polyvinyl alcohol penetrates the wood pores and dramat-ically boosts fiber tear. Higher-molecular-weight partially hydrolyzed polyvinyl alcohol allows the adhesive to sit on the surface of the wood, thus improv-ing adhesive holdout. A proper balance of penetration and holdout serves to distribute the strain over a wider area of the glue line that develops fiber tear. The polyvinyl alcohol may be borated to enhance wet tack. Consumer/Craft Glue. Partially hydrolyzed polyvinyl alcohol is used for good adhesion to wood and paper and for easy clean-up. Addition of boric acid is possible. Applications: high performance wood and consumer/graft glue. Partially hydrolyzed polyvinyl alcohol resin. Used as the major component in adhesives. Provides high tensile strength, ease of film formation, very good adhesion to cellulosic substrates such as paper and wood and bonding characteristics. Shows resistance to greases, petroleum hydrocarbons and animal or vegetable oils, and to organic solvents. Offers penetration into wood and development of fiber tear. Gives strength, heat resistance and good adhesion to wood and paper. Applications: high performance wood and consumer/graft glue.