Influence of inorganic nanoparticles on the glass transitions of polyurea elastomers (Phys. Status Solidi A 11∕2013)

The properties of polymers can be significantly changed by incorporating nanoparticles, which yields a great potential for applications. In the study by Reinecker et al. (pp. 2320–2327), nanocomposites of new polyurea elastomers filled with MoS2 nanotubes are investigated. The artwork illustrates the basic principle of the method used to perfom the most essential measurements of this work, dynamic mechanical analysis (DMA). Superimposed on the sample polymer-nanocomposite strip is the corresponding skeletal formula. Also shown are schematics of the featured components, polyurea (background network structure) filled with MoS2 nanotubes (ball and stick model, lower right corner). The two most descriptive and easily discernible graphs taken from the paper represent a good part of the achieved results. The figures show the real and imaginary part of the complex Young's modulus, E' and E′′ respectively, of pure polyurea JD-2000 compared with the nanocomposite JD-2000/MoS2. It is notable that the annealing temperature for removing the hydrogen bonds is influenced by the presence of nanotubes, shifting to higher temperatures in comparison to the pure elastomer (inset of figure showing E′).