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Flocculation of PVC Latex Particles in the Presence of Vinyl Chloride

  • Helen Hassander
  • Holger Nilsson
  • Christer Silvegren
  • Bertil Törnell

Summary

A study has been carried out to elucidate the mechanism of a process by which a polyvinyl chloride (PVC) resin in powder form is obtained by flocculation of a PVC latex in the presence of liquid vinyl chloride monomer (VCM). The steps in the process were:
  1. 1.

    addition of a flocculating polymer to the latex,

     
  2. 2.

    addition of VCM under thorough stirring, and

     
  3. 3.

    evaporation of VCM.

     

The PVC latex used was stabilized by ammonium laurate; the flocculating polymer was a polyvinyl alcohol with a low degree of hydrolysis. The agglomeration process was found to proceed in two steps. In the first, the particles flocculated and formed primary aggregates containing hundreds of latex particles. By addition of VCM these aggregates rapidly passed into the VCM phase forming macroscopic agglomerates, the precursors to the resin powder particles. During the passage into the VCM phase most of the laurate desorbed. The flocculating polymer also desorbed, but at a much lower rate.

During the evaporation step this polymer was readsorbed, whereas the laurate remained in the serum phase; during the last stage of this step, the specific surface area of the resin phase decreased sharply, indicating a large degree of particle coalesence.

Keywords

Latex Particle Sodium Lauryl Sulphate Vinyl Alcohol Recede Contact Angle Serum Phase 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Plenum Press, New York 1980

Authors and Affiliations

  • Helen Hassander
    • 1
  • Holger Nilsson
    • 1
  • Christer Silvegren
    • 1
  • Bertil Törnell
    • 1
  1. 1.Department of Chemical TechnologyThe Lund Institute of TechnologyLund 7Sweden

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