Novel polyamide 12 based nanocomposites for industrial applications

In this paper novel electro-active polyamide 12 (PA12) based nanocomposites were prepared though melt compounding by adding different kinds of carbonaceous nanofillers. The thermo-electrical properties of the bulk samples were then compared with those of the corresponding fibers. FESEM images highlighted an homogenous dispersion of carbon black (CB) and carbon nanofibers (CNF) within the matrix, while exfoliated graphite nanoplatelets (xGnP) based nanocomposites showed an aggregated morphology. A slight increase of the glass transition and of the crystallization temperature was evidenced by DSC tests, while thermogravimetric analysis showed an improvement of the thermal degradation resistance. Nanofiller addition promoted substantial increments of the elastic modulus coupled with an electrical resistivity drop up to 103 Ω cm, with interesting synergistic effects for nanocomposites filled with both CB and CNF. FESEM micrographs on the fibers demonstrated how the drawing process promoted the breakage of CB aggregates and their alignment along the drawing direction, leading to an increase of both the elastic and failure properties with respect to the neat fibers. On the other hand, nanofiller orientation led to an electrical resistivity enhancement of two orders of magnitude with respect to the corresponding bulk materials, and a CB amount of 10 wt% was thus required to observe a sensible fiber heating upon voltage application.