Polypyrrole-coated latex particles as core/shell composites for antistatic coatings and energy storage applications

Antistatic coatings based on latexes of core/shell composites were prepared from poly(styrene-co-butyl acrylate-co-acrylamide-co-acrylic acid) (PSBAA) core and polypyrrole (PPy) shell. PSBAA was prepared by semicontinuous seeded emulsion polymerization in a typical process to that implemented in the industrial scale. The copolymer-emulsified particles were surface-modified by in situ polymerization of 2 and 10 wt% pyrrole to PSBAA solid to yield PSBAA/2PPy and PSBAA/10PPy composites, respectively. The purpose of this modification is to enhance the electrical properties of PSBAA particles, thus preventing the buildup of static electricity on their coatings. The composites were characterized by FTIR, DSC, TGA, XRD, DLS, TEM, SEM, and EDX. The mechanical, antistatic, and dielectric properties of the coatings were determined. The volume resistivity of PSBAA/2PPy and PSBAA/10PPy composites was 2.60 x 10(9) and 1.2 x 10(7) Omega.cm, respectively, that is, proper to act as antistatic coatings. AC conductivity (sigma(ac)) measurements showed that the modification of PSBAA transferred it from insulator material with sigma(ac) 1.83 x 10(-10) S/cm to semiconducting material PSBAA/10PPy with sigma(ac) 8.33 x 10(-8). The increase in dielectric constant from 0.73 in PSBAA to 149.90 in PSBAA/10PPy indicates that the prepared composites represent promising candidates to be used as energy storage materials in electronic devices.