Piezoresistive PP/EPDM (TPV) Thermoplastic Vulcanizate Nanocomposites Based on Nanographite / Nanoclay Hybrid

Attempts have been made to prepare pressure sensitive electrically conductive nano composites based on PP/EPDM vulcanizate and hybridized conductive system composed of nanographite and nanoclay. For this purpose, melt mixing process was employed. The role of electrically charged clay silicate layers in conductivity threshold as well as pressure sensitivity (piezoresistive) of the samples has been evaluated. Results revealed that clay nanolayers can play important role in interconnectivity of the graphite conductive networks, and hence pressure sensitivity of the composites. Rheological and mechanical properties of nanocomposites containing various amounts of nanographite and nanoclay were evaluated with RMS and tensile strength measurements. The dispersion behavior of nanographite and nanoclay particles was investigated by field emission scanning electron microscopy. All electrically conductive nanocomposites based on nanographite exhibited positive piezoresistive behavior above their conductive threshold. At higher nanographite concentration, the conductive paths formed in the composites may be saturated, thus leading to weak response in resistivity with external pressure. Incorporation of charge carrier silicate layers into the structure of nanocomposites led to the reduction of conductivity, indicating that clay particles have divers effect upon interconnectivity of graphite nanoplatelets

کلیدواژه ها:

Piezoresistive ، PP/EPDM ، Nanographite ، Nanoclay