Morphological, dielectric, tunable electromagnetic interference shielding and thermal characteristics of multiwalled carbon nanotube incorporated polymer nanocomposites: A facile, environmentally benign and cost effective approach realized via polymer latex/waterborne polymer as matrix

Abstract

Recent years have witnessed an increased interest in the designing of composite materials in an uncomplicated and economical route for electromagnetic interference (EMI) shielding applications. Herein we report a simple; user friendly and cost effective method comprising of aqueous emulsion of polypropylene (PP) being used as the polymer matrix to manufacture uniformly and efficiently dispersed multiwalled carbon nanotube (MWCNT) incorporated PP composites with excellent electrical conductivity and EMI shielding potential; making use of non‐conventional fabrication techniques. Scanning electron microscopy (SEM) and field emission SEM (FE‐SEM) analysis revealed the uniform distribution of MWCNT's throughout the PP matrix. The dielectric constant and ac conductivity of the 20 wt% MWCNT incorporated sample showcased few order magnitude increment with the ac conductivity reaching as high as ∼66 S/m. Exemplary EMI shielding effectiveness (EMI SE) of ∼57 dB (S band), ∼47 dB (X band), and ∼44 dB (Ku band) was achieved during this study over a broad range of microwave frequency. The composites illustrated marginally improved thermal stability compared to that of neat PP; and the onset crystallization and crystallization temperatures increased with increasing MWCNT concentration. This simple process can be utilized to prepare fine tuned composites/blends of polypropylene with nanofillers/incompatible polymers easily and effectively. Present work also suggests that designing polymer composites based on matrices dispersed in aqueous media is a promising approach to prepare nanocomposites with high filler loading and tunable properties. POLYM. COMPOS., 39:E1169–E1183, 2018. © 2017 Society of Plastics Engineers

High electromagnetic interference shielding of poly(ether-sulfone)/multi-walled carbon nanotube nanocomposites fabricated by an eco-friendly route

“…This indicated that the nanocomposites exhibited almost similar EMI-SE in both the X-band and K u -band and there is a negligible variation with varying frequency. This is similar to the results reported by George et al [67] for the polypropylene (PP)/MWCNT nanocomposites prepared by the solution method followed by hot pressing. However, in contrast to the PES/MWCNT (which showed 29-30 dB) nanocomposites, the PP/MWCNT showed a total EMI-SE of about 25 dB for the 10 wt% MWCNT nanocomposite.…”

“…Abbas et al [27] reported an EMI-SE of 35 dB (in the X-band) for 20 wt% MWCNT filled Poly(ether-sulfone) (PES) nanocomposites (thickness = 0.5 mm) fabricated by the solution method. Similarly, George et al [28] reported an EMI-SE of ∼47 dB (in the X-band) for the 2 mm thick PP/MWCNT composite fabricated by the solution method followed by hot pressing. The functionalization of the CNTs can also increase the EMI-SE compared to CNTs without functionalization.…”

Improved dispersion of reduced graphene oxide in benzoxazine composites via electrostatic interaction with M‐cresol

“…In order to further illustrate the utility and advancement of in‐situ synthesized rGO/mC‐A, the comparison of the dielectric constants and EMI SE performance of our results and previously reported values are shown in Figure 5. As a result, Figure 5E, F demonstrate the superiority of in‐situ synthesized rGO/mC‐A with in terms of relatively high dielectric constants and EMI SE values at low addition of rGO, compared to other systems, such as CNT/Epoxy, [ 40 ] MWCNTs/Epoxy, [ 41 ] MWCNT/PS, [ 42 ] MWCNT/PP, [ 43 ] TGO/SCI/Epoxy, [ 44 ] Graphene/Epoxy, [ 45 ] GNPs/Epoxy, [ 46 ] rGM/Epoxy, [ 47 ] GNPs/Epoxy, [ 48 ] Graphene/PU, [ 49 ] Graphene/TPU, [ 50 ] at 8.2–12.4 GHz.…”

Porous Carbon–Carbon Composite Materials Obtained by Alkaline Dehydrochlorination of Polyvinyl Chloride

“…An important problem in the synthesis scheme of PCCCM considered above is to ensure close interaction of the modifying additive nanoparticles with the initial polyvinyl chloride molecules (or aggregates of molecules). This problem is of interest, per se; it is considered in many studies where PVC modification by carbon NC is used to render antistatic or shielding properties to NC/PVC composite materials [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ], to improve thermal or electrophysical properties [ 39 , 40 , 41 , 42 , 43 , 44 ], and to apply such materials in energy storage devices [ 41 , 42 ], chemical sensors [ 41 , 42 ] and microelectronics [ 39 , 44 ]. A uniform distribution of carbon nanoparticles in PVC melt or its solutions in organic solvents is obtained using ultrasonic treatment [ 33 , 40 , 41 , 42 , 44 , 45 ], preliminary surface functionalization of the modifying carbon nanoparticles [ 46 , 47 , 48 ], surfactant additives [ 49 , 50 ], and mechanical mixing in a dry form in special-purpose mills [ 35 , 39 , 42 , 43 ] or extruders [ 33 , 34 ].…”