The influence of chemical constitution on the structure and properties of polyimide fibre and their graphite fibre. (28th February 2019)

• Record Type: Journal Article
• Authors: Xiao, Meng; Zhang, Xingwei; Xiao, Wentao; Du, Jianjun; Song, Huaihe; Ma, Zhaokun
• Is Part Of: Polymer. Volume 165(2019)
• Page Start: 142
• Page End: 151
• Publication Date: 2019-02-28
• Subjects: Polyimide fiber -- Graphite fiber -- Thermal stability -- Thermal conductivity; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2018.12.047
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstracts: Randomly copolymerized polyimide(co-PI) fibres were prepared from pyromellitic dianhydride (PMDA), 4, 4′-oxydianiline (ODA), and p-phenylenediamine (p-PDA) by two-step wet spinning process. Co-PI fibres were carbonised at 1400 °C under a pure N2 atmosphere for preparing carbon fibre and then graphitised at 2800 °C under a pure Ar atmosphere for preparing graphite fibre. The influence of ODA/p-PDA molar ratios on the molecular weight and molecular weight distribution, chemical structure, morphology, thermal stability and carbonisation yield of co-PI fibre were carefully discussed. Co-PI fibres with 50% ODA content (POP-50%) has the highest thermal stability and the lowest heat release during the carbonisation process. The relationship of structure and property between co-PI fibres and co-PI based graphite fibres were analysed by XRD, Raman and thermal conductivity test. Co-PI based graphite fibres showed an increased graphitisation degree and crystal lattice size La(110) with the proper amount of ODA adding. The thermal conductivity of co-PI based graphite fibres showed a close relationship with La(110) . POP-20% reaches a maximum La(110) of 170 nm and the highest thermal conductivity of 305.2 W m −1 K −1 which is 35.2% higher than that of POP-0%. Graphical abstract: Graphite fibre with high thermal conductivity for effective heat dissipation prepared from co-polyimide fibre.Image 1 Highlights: Successfully converting co-Polyimide fibre into graphite fibre through simple graphitization process at 2800 °C. Graphitization degree of co-PI based graphite fibre can be induced with proper ODA/p-PDA molar ratio. Co-polyimide fibre with 20% ODA component reaches a high thermal conductivity of 305.2 W m −1 K −1 .