This formulation utilises a pre-emulsified monomer phase which is added continuously throughout the polymerisation.
FORMULATION 2-4
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1. A pre-emulsion is prepared by dispersing the monomers and di-methyl — ethanolamine in colloid dissolved in water.
2. The reaction vessel is charged with water, protective colloids and defoamer and the solution heated to 80°C.
3. At this temperature the ammonium persulphate (dissolved in some of the water) and ammonium hydroxide are added immediately the pre-emulsion feed to the reactor is commenced.
4. The pre-emulsion is fed into the reaction vessel over 2 hours whilst maintaining the temperature at 80-85°C.
5. When the addition is complete, the reactants are held at 80-85°C for a further 2 hours to ensure complete conversion and then cooled to 50°C for filtration via a vibrating screen fdter.