A preprepared monomer ‘‘seed’’ mixture, containing
all five monomers, was added to the flask, while
stirring, and the temperature was allowed to stabilize.
Then an initiator ‘‘seed’’ was similarly added to the
reaction vessel. The mixture was left for approximately
15 min to allow the latex ‘‘seed’’ to develop, before
commencing the monomer feeds. Monomer was fed
into the vessel at a rate of 1.5 mL/min. Initiator was
split into six equal portions and then added at halfhour
intervals during the monomer feeds. Throughout
the process the reaction temperature was maintained
at 80C; however, once the feeds were completed, the
temperature was raised to 83C and allowed to
stabilize for 15 min. A final portion of initiator was
then added and the reaction temperature was maintained
at 83C for a further 75 min, after which the
latex was cooled. The latex was filtered through a mesh
in order to remove large aggregates.