Enhancement of surface and bulk mechanical properties of polycarbonate through the incorporation of raw MWNTs — Using the twin-screw extruder mixed technique

In this paper, we present the effects of incorporated multi-walled nanotubes (MWNTs) on a metal surface and the bulk mechanical properties of as-synthesized PC/MWNTs composites that are prepared using the twin-screw extruder mixed technique. MWNTs used for preparing the composites were raw compounds that were not treated with any surface modifications. Transmission Electron Microscopy (TEM) subsequently characterized morphology for the dispersion capability of MWNTs in the PC matrix. In this experiment, the surface mechanical property studies (i.e., wear resistance and hardness) show that the integration of MWNTs exhibited a distinct increase on shore hardness was up to 5 wt.% of MWNTs loaded in composites. Moreover, the enhancement of wear resistance of as-prepared composites, compared to pure PC, can be further identified by the Scanning Electron Microscopy (SEM) observation of the surface morphology after testing. On the other hand, for the bulk mechanical property studies (i.e., tensile strength and flexural strength), we found that the composites containing 3 wt.% of MWNTs in the PC matrix exhibited the best performance in tensile strength and flexural strength. It means that this composition of MWNTs exhibit good compatibility with PC matrix, which may be attributed to the π–π interacting forces existing between the aromaticity of MWNTs and PC matrix. Furthermore, it was found that at higher MWNTs loading (e.g., 5 wt.%), raw MWNTs were to be aggregated in the polymer matrix, as observed in TEM. Also, the result leads to an obvious decrease in tensile and flexural strength tests.