| 摘要 |
Improved process for the preparation of partially alcoholyzed polyvinyl acetate having good compositional uniformity comprises rapid premixing of the polyvinyl acetate polymer and base catalyst solutions in a static mixer and carrying out the alcoholysis reaction in an intermeshing, self-wiping, twin-rotor mixer or mixing extruder. The process yields polyvinyl alcohol product having a maximum hot water insoluble fraction of about 1.1% by weight obtained by the proper adjustment of the feed temperature, the shear rate in the premixer and the catalyst concentration in the catalyst feed solution. |
