The performance of different redox initiator couples to initiate the emulsion polymerization of butyl acrylate at low temperature (40–50 °C) was investigated in both batch and seeded semibatch polymerizations. Polymerizations were carried out mimicking industrial conditions, that is, technical grade monomer and no N2 purging was used during the polymerizations. The redox systems used contained as oxidants persulfates or hydroperoxides and as reducing agents ascorbic acid, formaldehyde sulfoxilate (SFS), tetramethyl ethylene diamine (TMEDA), Bruggolit 6 and 7 (FF6 and FF7), and sodium metabisulfites. Batch experiments showed that for systems using persulfates, the ammonium persulfate (APS)/TMEDA system provided the lower induction period and higher conversion, whereas for the systems with hydroperoxide oxidants, tert‐butyl hydroperoxide (TBHP)/FF7, TBHP/SFS, and H2O2/FF7 were the best alternatives. When these selected systems were used in seeded semibatch experiments of BA with allyl methacrylate, it was found that to obtain similar kinetics and microstructure (gel content and crosslinking density) than in case of using a thermal initiator at 80 °C, the polymerization could be run at 40 °C if the reactor was purged with N2. Alternatively, in absence of N2 polymerization, temperature should be increased to 50 °C and initiator concentration increased. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2917–2927, 2009

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A simple way to obtain a conducting nanocomposite is described, and the conducting particles are characterized. Core-shell particles [polystyrene-polyaniline (PANI)] have been obtained by the dispersion process from three types of polystyrene latexes: a no-cross-linked core stabilized by a nonylphenolethoxylate (NP40) and two cross-linked cores stabilized by NP40 and a mixture NP40/Surfamid (a surfactant bearing an amide group). The surface of these particles has been extensively characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy, and scanning electron microscopy. A maximum coverage of 94% was obtained for the high PANI content as revealed by XPS analysis. A better coverage was obtained for the cross-linked polystyrene latex stabilized by the Surfamid. The amide group of this surfactant allows the H-bonding formation with the PANI backbone and, thus, improves the conductivity. It was shown that a uniform coverage of the core particles was not required to ensure a good conductivity.

Intrinsically conductive polymers (ICPs) and conductive composites offer many potential industrial applications due to their conductive properties, processability and mechanical properties. Much work has been carried out to develop the synthesis and formulation of various conductive polymers. Nevertheless, polyaniline (PANI) seems to be one of the most interesting conductive polymer based on the low cost of its synthesis, its conductive properties and its thermal and environmental stability. In this paper, we describe the synthesis and formulation of conductive composites containing PANI by considering two synthetic approaches. The first one is based on the oxidative polymerization of aniline. This synthesis has been optimized from laboratory‐scale to a 50 L pilot‐plant reactor. After a post‐doping procedure, the composite is obtained using a twin‐screw extruder. The second approach concerns a core/shell synthesis (polymer matrix/PANI) procedure which allows synthesis and formulation at the same time. Conductive composites of various compositions (polymer matrix/PANI content and additives) were synthesized by both of these methods and the advantages and drawbacks of each of them are discussed. Copyright © 2006 Society of Chemical Industry