Study on the rheological and electrical properties of PMMA/MWCNT nanocomposites prepared by in situ polymerization assisted by sonication

Carbon nanotubes have high mechanical, electrical and thermal properties that can be incorporated into polymer matrices. Nevertheless, in order to transfer their properties to the matrix, they need to be intimately dispersed in the polymer. This work presents an alternate route for the synthesis of polymer nanocomposites composed of multi-wall carbon nanotubes (MWCNTs) dispersed in a matrix of polymethylmethacrylate (PMMA) for application in optoelectronic devices. Nanocomposites of PMMA / MWCNTs were obtained in situ polymerization by a single reaction step with ultrasonic agitation in chloroform solution. The effect of the of MWCNTs content and ultrasound amplitude was evaluated in a factorial design of experiments. Rheological analysis (SAOS) for nanocomposites have shown at low frequencies, that the storage modulus (G’) tends to approach the loss modulus value (G”), probably indicating the approach of a percolation threshold. TEM analysis showed very well dispersed MWCNT in the PMMA matrix. The electrical conductivity measurements of the nanocomposites (10 mS/m) are typical of semiconducting materials used for EMI shielding applications; thus candidate them as potential polymeric materials for antistatic applications.