Electrically conductive sensors for liquids based on quaternary ethylene vinyl acetate (EVA)/copolyamide/maleated-EVA/polyaniline blends

摘要

Electrically conductive blends, containing two immiscible polymers (ethylene vinyl acetate copolymer, EVA-19, and copolyamide 6/6.9, CoPA), polyaniline (PANT), and maleated EVA compatibilizer were studied as sensing materials for a homologous series of alcohols. (methanol, ethanol, and I-propanol). Recent results have shown that the corresponding uncompatiblized blends exhibited a preferred localization of PANT in the CoPA phase, leading to a cocontinuous morphology (i.e., both the CoPA phase and the PANI component located in it are continuous). The concept of the compatibilizer addition was to improve compatibility between the EVA-19 and the CoPA, modifying the morphology of the PANI-containing blend and altering its sensing properties. Extruded EVA-19/CoPA/maleated-EVA/PANI filaments produced by a capillary rheometer process at various shear rate levels were used for the sensing experiments. The filaments displayed high sensitivity levels upon. exposure to the various alcohols as well as improved sensing stability and reproducibility at low compatibilizer contents. The sensing properties vary with compatibilizer concentration and are of inferior quality beyond a certain content. The sensing behavior of the compatibilized filaments is compared to, the previously reported results for the corresponding uncompatibilized filaments. (c) 2006 Wiley Periodicals, Inc.