Viscosity PVAC dispersion

This short discussion of problems associated with stabilizing dispersions of PVAc and its copolymers leads to the conclusion that the hydrophilic nature of VAc make placement of stabilizing species (surfactant, charge, hydrated layer, etc.) difficult without incurring additional problems (decrease in rate of polymerization, increase in the concentration of water-soluble oligomers, increase in viscosity, etc.). As a result, a combination of approaches is often used in commercial latex production. The need for better surfactants, especially reactive surfactants, for the emulsion polymerization of vinyl monomers is still evident... 

The water dispersions of PVAc were prepared under nitrogen atmosphere using a semi-batch emulsion polymerization technique, in a four-neck kettle equipped with a mechanical stirrer, an inlet for feeding streams and a reflux condenser. The reagent amounts, the reaction conditions and the yields for each preparation are reported in Table 5. Solids content, pH and viscosity were measured and reported in Table 5. 

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