Rheological, Dynamic and Tensile Mechanical Properties of Recycled Styrofoam Loaded with Carbon Nanotubes

Abstract

Styrofoam was recycled and then loaded with different volume fractions of multiwalled carbon nanotubes (MWC-NTs). The frequency dependence of complex viscosity η*, storage modulus E/ and loss modulus E// were studied. All of them were increased with increasing MWCNTs concentration. The dependence of the complex viscosity on CNTs concentration was found to obey the rheological percolation behavior with low percolation threshold and depends on frequency. The addition of MWCNTs to recycled Styrofoam did not change the glass transition temperature. The tensile properties of all composites were studied at different temperatures. Stress-strain curves at temperatures 30, 50, 70 and 90 °C showed brittle behavior. The elastic modulus, ultimate strength, strain at break, and energy density to break were increased with increasing both CNTs concentration and temperature up to 90 °C. The elastic modulus had a tensile percolation behavior with a threshold value close to that obtained for η*. Plastic deformation of all composites took place at 105 °C and sharp decrease in both E and σb was observed. Conversely, sharp increase in both strain at break and energy density to break was observed at temperature 105 °C. The material at this temperature was converted from polydomain to monodomain configuration.