Hybrids nanocomposites based on a polymer blend (linear low‐density polyethylene/poly(ethylene‐co‐methyl acrylate) and carbonaceous fillers (graphene and carbon nanotube)

Abstract

Interfacial or separate phase location of carbonaceous nanofillers (graphene and carbon nanotubes) in polymer blends with co‐continuous phases can lead to double percolation behavior, significantly increasing rheological and electrical properties. The prediction of the morphology and the location of the nanofillers has been used as a tool to evaluate the proprieties of co‐continuous polymer blends. This work aims to highlight the superior conductivity levels achieved using a low amount of carbon‐based fillers, by the proper selection in a multiphase polymer matrix as a template for controlled dispersion and spatial distribution of the nanoparticles, offering a compromise between easy processability and enhanced performance. Here, two polymers (linear low‐density polyethylene [LLDPE] and ethylene‐co‐methylacrylate [EMA]) and their co‐continuous blend (LLDPE/EMA) were loaded with nanofillers (few‐layer graphene [FLG], few‐walled carbon nanotube [FWCNT]) via continuous melt mixing in twin‐screw extrusion, separate and simultaneously. It was observed that the addition of the nanofillers changed the co‐continuity of the blend, with the probable migration of the nanofillers from the EMA (hydrophilic) phase to the LLDPE (hydrophobic) phase. Rheological percolation occurred preferentially in blends containing FWCNT and FLG/FWCNT. Electrical conductivity was observed in all compositions, with higher electrical conductivity being noticed in hybrids.

Tailoring the rheology and electrical properties of polyamide 66 nanocomposites with hybrid filler approach: graphene and carbon nanotubes

“…In addition, below frequencies of 10 0 rad s −1 , the tan δ values of the PA66/CNT nanocomposites (open and filled red stars) and the hybrid nanocomposite with GNP‐25 (black circles) became less than 1, indicating the transition to a solid‐like behavior. This rheological behavior has also been reported by Nunes et al 13 . in blends of PE/poly[ethylene‐ co ‐(methyl acrylate)] with both CNT and GNP included.…”

“…Interesting are the results for the relaxation times ( τ ). The value of τ represents the time the polymer chains take to relax completely while they are melt‐processed 13 . Although the tendency is not very clear with composition, it seems that the relaxations are faster in the GNP binary nanocomposites, and slower in the CNT binary and CNT/GNP hybrid filler nanocomposite with GNP‐25.…”

“…Faster relaxations would indicate a more liquid‐like response while slower relaxations would point to a solid‐like behavior, which agree well with the G ′ and G ″ behavior that was observed and already discussed for these systems. Higher relaxation times indicate a hindering of the polymer chain mobility due to the presence of a percolated network structure created by the nanofillers, and therefore longer times are required in order to break the interconnections 13 …”

“…Those values agreed well with our results. It has been reported that the rod‐like structure of CNT is more effective in creating conducting networks than the sheet‐like form of GNP 13 . In addition, the intrinsic electrical conductivity of the nanoparticles may have an influence on the electrical behavior obtained.…”

“…Therefore, a combined strategy has been proposed in order to address the rise of the viscosity and to gain the best features of both types of nanoparticles. With that purpose, the simultaneous use of both CNT and GNP as a hybrid filler have been evaluated in different types of matrices, from thermosetting to thermoplastic ones, 1–5 as well as in polymer blends 13 …”