About This Product
Polyvinyl formal results from the reaction of polyvinyl alcohol with formaldehyde and behaves as a thermoplastic. The resin offered here comes as a white powder with a softening point of about 190 °C, a thermal deformation temperature of 65–75 °C and water absorption of about 1%; literature values put its density at 1.23 g/mL at 25 °C and its refractive index (n20/D) at 1.502. It is soluble in acetone, chlorinated hydrocarbons, acetic acid and phenols. The resin is used for the insulating enamel on wire where the film has to resist abrasion, and in adhesives joining metal, wood, rubber and glass. Further uses are interlayers in laminated plastics and impact-resistant foamed plastics. No grade specification is given: solution viscosity, the formal, hydroxyl and residual acetate levels and volatile matter are confirmed on enquiry, along with packing. Four CAS numbers are quoted for this resin (63450-15-7, 9003-33-2, 63148-61-1 and 26876-25-5), so confirm which one applies to the grade supplied. The density and refractive index are literature figures rather than lot limits, and the colour should be checked on a sample, as a faintly yellow solid is also described.
