Preparation of microcellular low-density PMMA nanocomposite foams: Influence of different fillers on the mechanical, rheological and cell morphological properties

Poly(methyl methacrylate) (PMMA) nanocomposites were prepared by incorporating talc, carbon black (CB) and thermally reduced graphite oxide (TRGO) respectively. At a loading content of 5 wt %, the fillers were well dispersed within the PMMA matrix with the exception of CB. As expected, the inclusion of the respective fillers led to an increase of the tensile modulus at the expense of tensile strength and elongation at break compared to neat PMMA. The addition of TRGO (5 wt %) increased the dynamic complex shear viscosity (eta*) and storage modulus (G') of PMMA by one order of magnitude compared to talc and CB at the same concentration. Van Gurp-Palmen-plot further revealed the formation of filler network only for CB and TRGO particles. Physisorption measurements showed that TRGO and CB fillers were more CO2-phillic in comparison to talc and may have contributed to increasing the amount of CO2 retention as confirmed by sorption measurements. These features were exploited to prepare closed-cell microcellular low-density PMMA nanocomposite foams via batch-foam process. (C) 2015 Elsevier Ltd. All rights reserved.