Fabrication process of ethylene-vinyl acetate copolymer (EVA)/polypyrrole or polyaniline blends for pressure sensors

Abstract

Conducting rubbery blends offer attractive possibilities for developing pressure sensors, due to their unique properties, such as: flexibility, elastic deformation, and vulcanized rubber resilience associated with the electrical conductivity of the intrinsically conductive polymers. In this study, the effect of polypyrrole and polyaniline mixture that was doped with dodecylbenzenesulfonic acid in the electrical conductivity, and the electromechanical propriety of polymeric blends, with the EVA as the matrix, were studied. The EVA/PPy.DBSA or EVA/PAni.DBSA blends were prepared through the solution casting method, at room temperature, after dissolving both components in toluene as a common solvent. Blends with polypyrrole and polyaniline content above 20% of weight had higher volume of electrical conductivity than the corresponding solution casting blends of EVA/PAni.DBSA. The electrical conductivity variation, which occurs from the compression tension increase, was evaluated for the mixtures, with different compositions of PPy.DBSA and PAni.DBSA. The conducting polymer blends EVA/PPy.DBSA presented appropriate electromechanical proprieties to be used in pressure sensors.