The effect of temperature on the roll graphite films derived from Kapton polyimide films

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2024-07, Vol.130 (7), Article 497
• Main Authors: Lan, Yu, Xi, Yuchun, Xiong, Wei, Liu, Xiaoyang, Wang, Zhixin, Huang, Shirong, Lin, Jitao, Yin, Chuanqiang, Li, Xiaomin, Zhou, Lang
• Format: Article
• Language: English
• Subjects: Carbon content; Characterization and Evaluation of Materials; Condensed Matter Physics; Ductile-brittle transition; Electrical properties; Electrical resistivity; Graphite; Graphitization; Heat conductivity; Heat transfer; Heat treatment; Kapton (trademark); Machines; Manufacturing; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Polyimide resins; Polymer films; Prepolymers; Processes; Raman spectra; Surfaces and Interfaces; Temperature; Temperature effects; Thermal conductivity; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-024-07665-7

Aromatic polyimide films are widely used in high-tech fields due to their excellent combination of thermal, mechanical, and electrical properties. These films serve as precursors for the preparation of high thermal conductivity graphite films, with carbon content up to 70%, exhibits exceptional thermal and electrical conductivity, making it a promising precursor for polymer-based graphite films. This study focuses on the reserch of graphitization using commercial DuPont Kapton polyimide film. The polyimide film was rapped around a cylindrical mold and heat-treated at various temperatures. The impact of the process system on graphitization was thoroughly investigated, along with the evolution of polyimide’s structure and properties during heat treatment. Results demonstrated that the size of the prepared films initially increased and then decreased with the increase in graphitization temperature. Additionally, the color of the prepared films transitioned from yellow-brown to black and eventually gray matte. The brittleness of the prepared films followed a similar pattern of initially increasing and then decreasing. When the temperature was below 2200 °C, the surface of the graphite films was smooth and defectless. However, at 2200 °C, small holes appeared on the surface, and at 2300 °C, the surface began to exhibit a “foaming” phenomenon, which intensified with temperature. XRD and Raman spectra analysis revealed that the degree of graphitization, crystallinity, and order of the prepared films increased with temperature. At 2800 °C, the sample achieved a theoretical degree of graphitization of 95.35% and a thermal conductivity of 1246.36 W/(m·K).