Preparation of flexible, highly conductive polymer composite films based on double percolation structures and synergistic dispersion effect

Abstract

We studied for the first time the synergistic dispersion effect of the carbon nanotube (CNT)/graphene (Gr) and polypropylene (PP)/polycarbonate (PC) (1:1) double percolation structures on conductive polymer composites (CPCs). PP/PC/CNT/Gr films with different CNT/Gr ratios are prepared by melt blending and hot pressing. Results showed that a CNT/Gr ratio of 1:1 facilitated the creation of co-continuous double percolation structures of matrices, and the electronic conductivity reached 33.11 S/m, which was five times greater than that of the matrices containing only CNT. Results showed that the synergistic dispersion effect and the co-continuous double percolation structures provided the matrices with conductivity through an additive effect. Meanwhile, PP/PC/CNT/Gr composite films possessed good thermal stability and hydrophobicity. They also did not exhibit thermal degradation at 300 C and had a water contact angle of 94.5 . However, PP and PC were incompatible, causing considerable brittleness of composite films macroscopically, and the films can hardly curve. To respond to this downside and improve the flexibility, a small amount of thermoplastic polyurethane (TPU) was added to the system. The presence of TPU helped combining the two materials in different phases, thereby strengthening the continuity. However, the presence of TPU adversely affected the double percolation structures and dispersion state of fillers, and subsequently decreased the conductivity.

Preparation of carbon black/graphene nanosheets/PP composites with 3D separated conductive networks based on selective laser sintering

“…(2) forming a conductive network with a lower percolation threshold; (3) due to the synergistic effect of fillers, the mechanical properties and electrical conductivity are improved. [36,37] It is proposed to use zero-dimensional CB and two-dimensional graphene together, adjust the proportion of composite fillers, improve the aggregation state of CB, and increase the contact area between the mixed fillers, The conductivity and mechanical properties of CPC can be improved by adjusting the microstructure and conductive network of CPC. Rollo et al [38] used a mixture of 1 wt% multiwalled carbon nanotubes (MWCNTs) and graphene (GE) nanoparticles (70/30wt/ wt) to modify TPU powders by encapsulation, and the results showed that MWCNTs and GE synergistically enhanced the electrical conductivity of TPU-based composites.…”

Enhanced Electrical and Thermal Conductivities of Polymer Composites with a Segregated Network of Graphene Nanoplatelets

“…Various strategies [20][21][22][23][24][25][26] have been proposed to achieve excellent electrical and thermal conductivities of polymer composites by incorporating smaller amounts of fillers. Double percolation can be generated by the selective localization of nanofillers based on thermodynamic (chemical affinity) and kinetic (melting point difference) factors between nanofillers and an immiscible matrix [20]. This strategy induces a predominant distribution of conductive fillers in one matrix phase.…”