Influence of blending protocol on the mechanical, rheological, and electromagnetic properties of PC/ABS/ABS‐g‐MAH blend‐based MWCNT nanocomposites

Abstract

AbstractPolycarbonate (PC)/acrylonitrile‐butadiene‐styrene copolymer (ABS) blend‐based multi‐wall carbon nanotubes (MWCNT) nanocomposites is an attractive alternative for the manufacture of electronics housing as it can have the mechanical and electromagnetic properties required for this application. The preferred location of MWCNT in PC/ABS blend is an important parameter to obtain better mechanical and electromagnetic properties. In this way, three different blending protocols (BP) were used to obtain PC/ABS/maleic anhydride‐grafted ABS (ABS‐g‐MAH) (85/10/5) blend‐based MWCNT nanocomposites with the addition of 0.5 and 1 wt% of MWCNT in a twin‐screw extruder. Specimens were evaluated by thermal (thermogravimetric analysis—TGA and differential scanning calorimetry—DSC), mechanical (Izod impact strength and tensile tests), dynamic mechanical analysis (DMA), electrical, and rheological properties, which were correlated with the nanocomposites morphology evaluated by high‐resolution scanning electron microscopy. The BP associated with the addition of a compatibilizer agent influenced the MWCNT distribution and location in the polymeric matrix. The one‐step extrusion process results in MWCNT mostly at the interface of the PC/ABS blend and agglomerates, leading to lower mechanical and thermal properties. The BP in which a PC/MWCNT masterbatch was first prepared and then diluted in ABS and ABS‐g‐MAH achieves the higher mechanical properties, increasing Young's modulus and the ultimate tensile strength. The third BP in which MWCNT was added in a second step in the blend already processed resulted in a homogeneous dispersion of MWCNT on both phases and a lower electrical resistivity.