Electrochemical Preparation of Elastic Conductive Films with Polypyrrole and Tri-block Polyelectrolyte

摘要

Producing a conducting polymer material, which has both elasticity and durable electric conductivity are a goal that deserves much effort. Blending conducting polymers or in situ polymerizing π-conjugated polymers in rubbery medium could increase elasticity of conducting materials. In these blends, conductivity is achieved by percolation of the dispersed conducting polymers phase hosted in insulating matrices. Significant achievement has been obtained to reduce the percolation threshold by forcing π -conjugated polymers into three-dimensianally minor continuous phase by the self-assembly techniques. To improve the stability of conductivity, polyelectrolytes were also used as macromolecular dopant against the diffusion out effect. One category of polyelectrolyte such as sulfonated tri-block copolymer of styrene/(hydrogenated) butadiene was used as dopant and allow the formation of free-standing films of polypyrrole. Despite these efforts, it nevertheless remains the case that there is phase separation of dispersed conducting phase and continuous phase during the application. In this preprint, we choose sulfonated [poly(styrene-ethylene/butylene-styrene) resin] (S-SEBS) as the dopant to electropolymerize conducting polymer films. Dynamic mechanic thermal analysis (DMTA) measurements find that the glass transition of the sulfonated polystyrene block at about 168 °C was replaced by the rubber plateau, indicating the formation of network by certain crosslink interaction. Raman scattering and UV spectroscopy provide evidences suggesting that polypyrrole segments crosslink the S-SEBS elastomer through the doping of the sulfonated entities. Conducting rubber of such topology suppresses the phase separation and provides stable conductivity even at the elongation ratio over 120%.