اثر شرايط اختلاط بر خواص فيزيكي و مكانيكي آميزه‫هاي نانوكامپوزيتي بر پايه‫ NBR/PVC/Nanoclay

Effect of Mixing Conditions on Mechanical and Physical Properties of Nanocomposites Based on NBR/PVC/Nanoclay

mixing conditions of NBR/PVC nanocomposites such as mixing tempera¬ture, rotor speed and mixing time are determining parameters in rheologi- cal, mechanical and morphological properties of the compound. Three lev¬els were chosen for each parameter using Design Expert software via Box-Behnken method. The nanocomposite samples were melt-mixed in Brabender internal mixer. The effect of various mixing parameters such as mixing temperature, rotor speed and mix¬ing time was investigated by stress-strain and rheological curves. The TPE nanocom¬posites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic mechanical thermal analysis (DMTA), and mechanical properties. It was found that only at low temperature, high tensile strength, storage mod¬ulus and low swelling index were obtained by increasing the rotor speed and mixing time simultaneously. As a consequence by increasing the mixing temperature samples undergo two processes. The former is self-crosslinking that leads to torque rise, and the latter is torque drop due to chain sessions. The morphology of nanoclay layers in poly¬mer matrix was studied by X-ray diffraction and TEM. By studying the mechanical and rheological properties of the nanocomposites the optimum preparation condition was found to be the temperature of 160°C, mixing speed of 50 rpm at 6 min.