Characterization of graphite-polyurethane composites used as electrode materials

Graphite powder was mixed with polyurethane in order to prepare composite materials in different proportions intended to be used in voltammetric analysis. Results of thermogravimetry, differential scanning calorimetry and dynamical mechanical analysis were used in the characterization of the composites. Thermal and visco-elastic behavior of pressed and non-pressed graphite-polyurethane composite used as electrode materials was investigated regarding the graphite content. TG curves revealed that thermal stability increases with the graphite content. DSC presented that the composites are completely cured after 24 h and DMA was used in the determination of glass transition of the composites, showing that the pressing during the cure resulted in lower mobility of polymeric chains inside the composites. DMA curves of GPU composites, using a dual cantilever clamp, between - 50 and 120 °C, heating rate of 5.0 °C min-1, frequency of 1.1 Hz and samples with 35 ± 1 mm (length) x 13 ± 1 mm (wide) x 3.5 ± 0.2 mm (thickness).