Core-shell latices based on conductive polymers

A poly(butyl methacrylate) (PBMA) latex was coated with a thin polypyrrole (PPy) layer in a chemical in situ polymerization. Ammonium persulfate and Fenton's reagent were used as the oxidants. The influence of reaction time on the conversion of pyrrole and on the conductivity of the resulting coated latices was investigated. Furthermore, the influence of the reaction atmosphere was investigated. It was found that the ammonium persulfate-oxidized reaction was quite insensitive towards the reaction atmosphere, whereas the Fenton's reagent oxidized system was very sensitive. In the latter system, when kept in air the conductivity reached a maximum after 30 minutes. In a nitrogen reaction atmosphere the conductivity gradually increased. The maximum conductivity, which was about 20 times as high as in air, was reached after 90 minutes and remained stable.