Nanocomposites Based on Isotactic Polypropylene-Copper Nanoparticles as Electromagnetic Shields

Hybrids based on isotactic polypropylene (iPP) and various concentrations of copper nanoparticles (up to a 15% by volume) have been prepared in order to analyze their electromagnetic interference shielding response and, consequently, their capability of being a good alternative to replace metals for that application. Promising results have been found in this area since shielding effectiveness values higher than 40 dB (which provide at least a 99% attenuation of the electromagnetic radiation) are reached. In addition, the Cu nanoparticle incorporation leads to other interesting improvements in several ultimate properties. Thus, these hybrids are being transformed from insulator into conductor materials, with an increase in conductivity amounting to around 14 orders of magnitude (at 1 Hz), due, in part, to the fact that the Cu nanoparticles are homogeneously dispersed within the iPP matrix, as deduced from SEM pictures. This enhancement is even more noticeable in mechanical properties since the elastic modulus (at room temperature) is doubled on passing from neat iPP to the nanocomposite with a Cu content of 15 vol.%. All these features make these hybrids as suitable candidates to be employed against electromagnetic interference and electrostatic discharge. The replacement of metals for various shielding applications also involves a significant reduction in weight.