Impact of injection‐molding processing parameters on the electrical, mechanical, and thermal properties of thermoplastic/carbon nanotube nanocomposites

Abstract

Thermoplastic nanocomposites, based on high-density polyethylene, polyamide 6, polyamide 66, poly(butylene terephthalate), or polycarbonate and containing multiwalled carbon nanotubes (CNTs), were compounded with either neat CNTs or commercial CNT master batches and injection-molded for the evaluation of their electrical, mechanical, and thermal properties. The nanocomposites reached a percolation threshold within CNT concentrations of 2-5 wt %; however, the mechanical properties of the host polymers were affected. For some nanocomposites, better properties were achieved with neat CNTs, whereas for others, master batches were better. Then, polycarbonate and poly(butylene terephthalate), both with a CNT concentration of 3 wt %, were injectionmolded with a screening design of experiments (DOE) to evaluate the effects of the processing parameters on the properties of the nanocomposites. Although only a 10-run screening DOE was performed, such effects were clearly observed. The volume resistivity was significantly dependent on the working temperature and varied up to 4 orders of magnitude. Other properties were also dependent on the processing parameters, albeit in a less pronounced fashion. Transmission electron microscopy indicated that conductive samples formed a percolation network, whereas nonconductive samples did not. In conclusion, injection-molding parameters have a significant impact on the properties of polymer/CNT nanocomposites, and these parameters should be optimized to yield the best results.

Energy-Efficient Enhancement for Viscoelastic Injection Rheomolding Using Hierarchy Orthogonal Optimization

“…It is necessary to determine the choice of the scheme from many aspects [54]. According to the previous analysis results, select the two gates type.…”

Influence of injection molding parameters on electrical resistivity of carbon nanotube reinforced polycarbonate

“…Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 6/22/15 9:19 AM Table 10 Comparison of injection molding parameters with Rios ' s study [22] .…”

“…After preparing composite granules by diluting PC/MWNT masterbatch which had 15 wt% MWNT content by using a twin screw extruder down to 2 wt% and 5 wt%, they produced test specimens by injection molding and conducted electrical tests [22] . It was observed that resistivity values of neat PC in Rios ' s study were well matched with the present study, but there was a difference between volume resistivity results of specimens having 5 wt% MWNT, as seen in Tables 10 and 11 . For comparison, injection temperature (300 ° C) and injection rate (35 cm 3 /s) were selected as base parameters of this study.…”

“…In another study, electrical resistivity tests were conducted on injected molded specimens having MWNT content of 2 wt% and 5 wt%, respectively [22] . After preparing composite granules by diluting PC/MWNT masterbatch which had 15 wt% MWNT content by using a twin screw extruder down to 2 wt% and 5 wt%, they produced test specimens by injection molding and conducted electrical tests [22] .…”

Compression Moulding of Thermoplastic Nanocomposites Filled with MWCNT

“…Four grades were chosen (from 1 to 8 wt.%) but the researchers just observed a strong dependence of the Young's modulus and the rupture strain on the CNT content. In a wider study, Rios et al evaluated the effects of the injection-moulding parameters on the electrical, mechanical, and thermal properties of several CNT filled composites 6 . High-density polyethylene (HDPE), polyamide 6 (PA6), polyamide 66 (PA66), polybutylene terephthalate (PBT), and polycarbonate (PC) were selected as matrices.…”