PVA

PVA, or Polyvinyl Alcohol, is a water soluble, colorless synthetic resin, primarily used to treat paper and textiles. Sometimes, it is supplied as a solution in water, or as beads. The compound is notable in that, as a polymer, it is not derived from monomer polymerization reactions. Rather, it is produced by dissolving PVAc (polyvinyl acetate) into alcohol, then adding sodium hydroxide or another alkaline catalyst. PVA has good adhesive, film forming and emulsifying attributes. Furthermore, it is resistant to solvents, oil and grease. It has good tensile flexibility and strength, along with aroma barrier and high oxygen properties. Nonetheless, in humid conditions, these properties are less pronounced. Often, it is used as a base material for the production of other resins, and in emulsifiers and adhesives -- as a protective, water soluble film. It is often used to make vinylon fibers. PVA biodegrades gradually and is nontoxic.