Enhanced properties of poly(styrene–b–ethylene–co–butylene–b–styrene) nanocomposites with in situ construction of interconnected graphene network

Abstract

In this work, such elastomeric nanocomposites were fabricated with graphene (GE) sheets selectively distributing between polymer matrices and forming three-dimensional networks. The solvent evaporation process was first introduced to produce poly(styrene-ethylene-co-butadiene-b-styrene) (SEBS) microspheres and then reduced GE oxide attached to the surface of SEBS microspheres via electrostatic interaction and sonication-assisted reduction. The microstructure of nanocomposites, prepared by compression molding using SEBS/GE microspheres, was investigated using scanning electron microscopy and transmission electron microscopy. The results showed that interconnected GE networks formed in heat-pressing composite and was destroyed after twin-roll mixing. The SEBS/GE nanocomposites showed enhanced electrical, thermal, and mechanical properties. The electrical resistivity of nanocomposites obtained via heat-pressing reached to 1.1 × 10 3 Ω m at a 2.5 wt % (1.07 vol %) content of GE. The thermal and mechanical properties were also characterized. It was found that the initial degradation temperature increased by nearly 40 C and the mechanical properties continued to rise with GE content below 0.5 wt %.

Effect of π–π Stacking Interfacial Interaction on the Properties of Graphene/Poly(styrene-b-isoprene-b-styrene) Composites

“…According to the electrical percolation theory, graphene sheets provide percolated pathways for electron transfer, which imparts electric conductivity to the nanocomposites. However, the improvement efficiency of graphene sheets dramatically depends on the degree of sheets’ dispersion and interfacial interaction [ 32 , 33 ]. The electrical properties of graphene/SIS composites obtained with different contents of graphene were investigated in detail.…”

“…This improvement in thermal stability could be attributed to the tortuous path effect, which formed between graphene and SIS through π–π stacking [ 10 , 40 ]. The decreased degradation rate with increase in graphene content can be ascribed to the effective obstruction of low molecules from degraded SIS, and the shield function of the heat [ 32 ].…”

“…It is found that all the composites present similar degradation behavior to pristine SIS, and the composites have an obvious improved thermal stability in comparison to pure SIS, especially in the range of 30-350 • C. This improvement in thermal stability could be attributed to the tortuous path effect, which formed between graphene and SIS through π-π stacking [10,40]. The decreased degradation rate with increase in graphene content can be ascribed to the effective obstruction of low molecules from degraded SIS, and the shield function of the heat [32].…”

Relationship between the Microstructure and Performance of Graphene/Polyethylene Composites Investigated by Positron Annihilation Lifetime Spectroscopy

“…This improvem of thermal stability can be ascribed to the tortuous path effect, which formed betw graphene and PE through CH-π interaction [17,29]. The thermal stability increased w the increase of graphene content can be ascribed to the effective obstruct towards l molecules from degraded PE, and the shield function to the heat [46]. This result is c sistent with the variation of the relative free volume fraction fr with the graphene cont (Figure 2c), because the thermal stability is related to the free volume fraction.…”

Recent Studies on Thermally Conductive 3D Aerogels/Foams with the Segregated Nanofiller Framework

“…However, other approaches, including adding a higher weight percentage of particle fillers, are less effective, as they deteriorate the mechanical integrity of thermally conductive polymer composites. However, the in-situ fabrication of a connected conducting composite network is another easy and scalable method that has been reported in recent years for fabricating thermally conductive 3D-framework polymer composites [103][104][105]. In this procedure, following the fabrication of carbon nanomaterial-based polymer composites, polymer powders are first precoated with a thermally conductive filler before being hot-pressed and compressed into a monolith framework.…”