Simultaneous enhancement in mechanical strength, electrical conductivity, and electromagnetic shielding properties in PVDF–ABS blends containing PMMA wrapped multiwall carbon nanotubes

Abstract

A unique approach was adopted to drive the multiwall carbon nanotubes (MWNTs) to the interface of immiscible PVDF-ABS blends by wrapping the nanotubes with a mutually miscible homopolymer (PMMA). A tailor made interface with an improved stress transfer was achieved in the blends with PMMA wrapped MWNTs. This manifested in an impressive 108% increment in the tensile strength and 48% increment in the Young's modulus with 3 wt% PMMA wrapped MWNTs in striking contrast to the neat blends. As the PMMA wrapped MWNTs localized at the interface of PVDF-ABS blends, the electrical conductivity could be tuned with respect to only MWNTs, which were selectively localized in the PVDF phase, driven by thermodynamics. The electromagnetic shielding properties were assessed using a vector network analyser in a broad range of frequency, X-band (8-12 GHz) and Ku-band (12-18 GHz). Interestingly, enhanced EM shielding was achieved by this unique approach. The blends with only MWNTs shielded the EM waves mostly by reflection however, the blends with PMMA wrapped MWNTs (3 wt%) shielded mostly by absorption (62%). This study opens new avenues in designing materials, which show simultaneous improvement in mechanical, electrical conductivity and EM shielding properties.

Fused filament fabrication of polymer composites for extreme environments

“…It is interesting to notice that samples with PVDF show a significant reduction in elongation. This result is in agreement with a previous work showing that the weaker mechanical properties of PVDF reduce elongation of a PVDF/ ABS composite material [16]. We infer that all of the 1.75E filaments experience a necking phenomenon, where the filament gets thinner as it extends [34], which is expected in thicker materials, while none of the 0.5P filaments exhibit this behavior.…”

“…Its glass transition temperature (T g ) is at around 105°C and remains unchanged when the polymer is incorporated into the composite (not shown in the DSC curves). Composites comprised of ABS and PVDF are known to phase-separate [15,16], so this implies that while the filament can be fabricated and 3D printed, it is not a true blend. On the other hand, Bi and PVDF exhibit endotherm and exotherm peaks, as shown in Figs.…”

“…In this work, we describe the preparation of highly filled FFF filaments containing three different components: ABS, Bi, and polyvinylidene fluoride (PVDF). PVDF is an attractive hydrophobic polymer to be incorporated in the fabrication of filaments since it exhibits high chemical resistance [15,16] and is widely used in numerous applications from electrical storage [17] to membrane filtration, distillation, and ion exchange [18,19]. Our filaments were created to be used by the FFF technology to 3D print objects that would experience combined extreme environments, such as exposure to ionizing radiation and solvent species.…”

High‐performance electromagnetic interference shielding material based on an effective mixing protocol

“…This low electrical percolation threshold value is due to the high aspect ratio observed for the MWCNTs and their three‐dimensional network formation. The lower percolation threshold value is a clear indication of three‐dimensional conductive network patways …”

Multifunctional polymer composites reinforced by carbon nanotubes–Alumina hybrids with urchin-like structure

“…This unavoidably generates π conjugation disruption, sidewall defects and shortening of nanotubes, and significantly impacts the composite mechanical properties and more profoundly their thermal and electrical properties. The non-covalent ways such as polymer wrapping [12,13] and surfactants [14], based on van der Waals forces or π-π stacking, are still limited due to the low thermal stability and weak mechanical performance of surfactants, compatibility, etc. Thus, a compromise between good dispersion and property deterioration is generally made for the available CNTs-contained composites.…”