Abstract
This study investigates the influence of sonication on the viscosity and mechanical properties of polymeric nanocomposites. Nanocomposites made with sonication show better mechanical properties than the analogous nanocomposites made with mechanical mixing only.
In this work the comparison of polymer matrix properties with and without sonication as well as nanocomposites produced with and without sonication is performed. Parameters of study are temperature level, time of sonication, concentration of nanoparticles [nanoclay], type of neat polymer (vinyl ester, epoxy), and percentage level of catalyst (for kinetics study). It is shown that the viscosity of polymer matrix is increased after sonication and cooling to the initial temperature (Figure 1). The kinetics of solidification checked with help of viscometry is changed also. Viscometry studies significantly affect the nanoparticles dispersion quality and properties of the nanocomposite. Results indicate that there are shifts in mechanical characteristics of polymer matrix and nanocomposites. Decreases in Young's modulus and strength of polymer matrix are experienced while ultimate strain and energy absorption properties exhibit increases (Table 1). Data tend to confirm the hypothesis that cavitations of the sonication process cause rupture of macromolecules and creation of free radicals which are attached as lateral branches making polymer more grafted and rubber-like.