In Situ Exfoliation of Graphite into Graphene Nanosheets in Elastomer Composites Based on Diels–Alder Reaction during Melt Blending

Abstract

We developed a new technique to in situ exfoliate graphite into graphene nanosheets and simultaneously prepare graphene nanosheets/elastomer composites based on the Diels− Alder (DA) reaction under strong shearing force transferred by the hydrogenated nitrile butadiene rubber (HNBR) during melt mixing. To realize the DA reaction, expanded graphite (EG) was used as a diene and maleic anhydride (MA) was chosen as the dienophile. The results show the efficient functionalization and exfoliation of EG into MA-functionalized graphene nanosheets (MAG), the good dispersion of MAG, and the formation of the MAG network structure in MAG/ HNBR composites at low content of MAG (∼1 wt %). These result in the significant increase in stress at certain strain and the electrical conductivity of MAG/HNBR composites over that of neat HNBR and EG/HNBR composites with 1 wt % MAG. Unlike the method used in solution, this method could be applied in industry for large-scale preparation of graphene nanosheets and their elastomer composites.

Highly Stretchable Poly(thiocarbonate)/Graphene Oxide Dielectric Composites toward a High Dielectric Constant and Low Dielectric Loss

“…The composites were prepared via the simple solution-mixing process between PPMTC and GO (Scheme b). The structure of GO was characterized by Raman spectra (Figure S2b), it is observed that a strong D band at about 1348 cm –1 and a strong G band at about 1600 cm –1 appear in the Raman spectrum, indicating that GO possesses significant structural disorders, , and the ratio of the D band to G band intensities ( I D / I G ) is about 1.15. Figure S2c shows the high-resolution XPS spectra of GO, it could be found that three distinct characteristic peaks corresponding to different functional groups of GO: C–C at 284.7 eV, C–O at 287.2 eV, and COO at 289.1 eV .…”

“…For the composites, the significant increase in stress is observed at about 330 and 300% for the PPMTC/GO0.1 and PPMTC/GO-GO0.3 samples, respectively; no obvious upturn in stress is found for PPMTC/GO1 until its ultimate rupture. The possible reason for the upturn of tensile stress in a certain tensile strain is the orientation of PPMTC mainchains or the strain-induced crystallization, , the orientation or the PPMTC crystallites acted as the reinforcing filler; a further study will be carried out to clarify the mechanism of the significant increase of stress for the PPMTC.…”

Ultrasonic-Assisted Diels–Alder Reaction Exfoliation of Graphite into Graphene with High Resveratrol Adsorption Capacity

“…Furthermore, the Diels-Alder reaction has been employed to chemically exfoliate graphite to obtain graphene and its analogs. In 2019, Tian [27] developed a method to exfoliate graphite in situ, in rubber and graphite blends, into graphene nanosheets based on the Diels-Alder reaction under strong shearing force. However, in the above methods, the exfoliation of graphite required strong shear force, and the thickness of the resultant exfoliated graphite was only reduced to the range of 0.1-1 µm.…”

Green Fabrication of High-Performance, Lignosulfonate-Functionalized, and Reduced-Graphene Oxide Styrene–Butadiene Rubber Composites

“…Graphene is a typical “2D material” in that it is a form of carbon with a single atomic layer thickness composed of an sp 2 hybrid structure . In the past decade, graphene has been widely explored in academia and industry due to its compelling features, such as an extraordinarily large specific surface area, ultrahigh strength, and excellent conductivity. , Consequently, graphene has become a promising filler candidate for rubber composites. − Among the preparation methods used for graphene/rubber composites, green latex compounding is an efficient method for the industrialization of achieving uniform dispersion of graphene and further improving the comprehensive properties of rubber composites. , However, the prerequisite for implementing the method is that both graphene and rubber molecular chains must be stably dispersed in the aqueous phase.…”