Accelerating the graphitization process of polyimide by addition of graphene

Abstract

In this article, a composite film from polyimide and thermally exfoliated graphene was prepared through in situ polymerization, and the weight percent of thermally exfoliated graphene with respect to the polyimide monomers was 5 wt %. The film was carbonized at 1000 C for 1 h and then heat-treated at various temperatures up to 2100 C. For comparison, the corresponding pure polyimide film was also prepared and heat-treated at the same condition. It was found that the addition of graphene could effectively prevent the polyimide film from shrinking in the direction parallel to the film surface during the heat treatment. Furthermore, the results of density, X-ray diffraction, shrinkage in the direction perpendicular to the film surface and scanning electron microscopy revealed that the graphitization process of the polyimide could be accelerated by addition of graphene obviously. In view of the above phenomena, a reasonable explanation was presented.

Free-standing functional graphene reinforced carbon films with excellent mechanical properties and superhydrophobic characteristic

“…6). It can be clearly seen that rGO sheets were uniformly dispersed in the PI matrix, which is in accordance with the work reported before [25]. .…”

3D Lamellar-Structured Graphene Aerogels for Thermal Interface Composites with High Through-Plane Thermal Conductivity and Fracture Toughness

“…Apparently, these Raman mappings indicate that graphitization converts PI to graphitized carbon and reduce GO to high-quality graphene. It is also seen that GO plays an inducing role in the conversion of PI to graphitized carbon because the large sheet of GO could promote the orientation of PI macromolecules and thus improve the graphitization extent of LSGAs [51,52]. In addition to the low lattice defects, and large graphene crystal size, the high quality of the vertically aligned skeleton walls is also crucial for thermal conduction of LSGAs.…”

Anisotropic and Lightweight Carbon/Graphene Composite Aerogels for Efficient Thermal Insulation and Electromagnetic Interference Shielding

“…The introduction of GO may be responsible for this change. Specifically, the rGO in PI/rGO composite aerogels promoted the orientation of PI molecule chains, and induced the graphitization transformation of the polymer matrix during the carbonization process, ultimately resulting in an increase in the graphitization degree of CG aerogels. , In addition, the d 002 value of rGO-800 was different from that of ideal graphene, which could be attributed to the incomplete reduction of rGO during 800 °C treatment …”