Abstract

RODRIGUES, Elton J. da R.; NASCIMENTO, Suéllen A. M.; TAVARES, Maria I. B.  and  MERAT, Pedro P.. On the influence of processing parameters on the molecular dynamics of melt intercalated polycarbonate-clay nanocomposites. Polímeros [online]. 2012, vol.22, n.5, pp. 436-439.  Epub Oct 11, 2012. ISSN 0104-1428.  http://dx.doi.org/10.1590/S0104-14282012005000058.

Polycarbonate-organofilic clay nanocomposites were obtained via the melt intercalation method in the blending chamber of a torque rheometer, under distinct values of shear and temperature. The influence of those processing parameters on the clay dispersion in the polymer matrix was probed by low-field nuclear magnetic resonance (NMR), using the T₁H measurement technique and by wide angle X-ray scattering (WAXS). The differences in longitudinal relaxation times and in the X-ray reflection patterns were correlated with the formation of relaxation domains with particular molecular mobility, as progressively larger intercalated morphologies were found in the nanocomposites due to the increase of shear stress and temperature. ¹H NMR has shown that both shearing and temperature have played a fundamental part on the polymer chains mobility, which explains the increase in the domain´s homogeneity following the increment of those processing parameters.

Keywords : Nanocomposite; melt intercalation; NMR.