Super-tough conducting carbon nanotube/ultrahigh-molecular-weight polyethylene composites with segregated and double-percolated structure

Abstract

Super-tough conducting carbon nanotube (CNT)/ultrahigh-molecular-weight polyethylene (UHMWPE) composites were prepared by a facile method; a very small amount of high-density polyethylene (HDPE) was used as the percolated polymer phase to load the CNTs. A structural examination revealed the formation of unique conductive networks by combination of the typical segregated and double-percolated structure, in which the fully percolated CNT/carrier polymer layers were localized at the interfaces between UHMWPE granules. Owing to the synergistic effect of the segregated and double-percolated structures, only 0.3 wt% of CNTs can make the composite very conductive. More interestingly, after the addition of only 2.7 wt% of HDPE, the ultimate strain, tear strength, and impact strength reached 478%, 35.3 N and 58.1 kJ m À2 , respectively; these corresponded to remarkable increases of 265%, 61.9%, and 167% in these properties compared with the conventional segregated materials. These results were ascribed to the intensified interfacial adhesion between UHMWPE granules, which resulted from the strong inter-diffusion and heat-sealing between the HDPE and UHMWPE molecules. A model was proposed to explain the outstanding ductility and toughness properties of the segregated and double-percolated CPC material.

Formation of Conductive Networks with Both Segregated and Double-Percolated Characteristic in Conductive Polymer Composites with Balanced Properties

“…In Figure 1B,i−m, the overall morphology of segregated and double-percolated network are more pronounced for SPP with the smallest particle size. 10,11,45 As shown in Figure 1B,a,e,i, it is apparent that the amount of conductive pathways augments with polymer particle size decreasing from ∼3600 μm to ∼898 μm for the same PENT concentration. Meanwhile, the thickness of PENT channels surrounding PP particles sequentially decreases and the boundaries between polymer particles are more visually obvious.…”

Effects of titanate treatment on morphology and mechanical properties of graphene nanoplatelets/high density polyethylene nanocomposites

“…In the nanocomposite, a completely different interfacial morphology is observed as compared with the bulk polymer due to the higher number of interfacial contacts of nanofillers with the polymer chains. The excellent electrical, thermal, and mechanical properties of graphene have already enthralled the attention of researchers for the generation of polymer nanocomposites . A single defect‐free graphene layer possesses excellent gas impermeability, specific surface area of ∼2600 m 2 /g, Young's modulus of ∼1.0 TPa, and thermal conductivity ∼6000 W/m K .…”

Studies on the selective localization of multi-walled carbon nanotubes in blends of poly(vinylidene fluoride) and polycaprolactone

“…Many studies were carried out to deal with the problem [11][12][13][14]. The design of double percolation structure in composites is one of the methods to reduce the percolation threshold of conductive fillers [15][16][17][18][19][20][21].The concept of double percolation was first proposed by Sumita et al [21] in immiscible blends that were filled with carbon black. Two requirements are needed to realize the double percolation structure in composites.…”