Research on the correlation between the performance of domestic high-strength and high-modulus carbon fiber in Ningbo

High-strength and high-mode carbon fiber has many advantages such as high specific modulus, small thermal expansion coefficient and dimensional stability. It is an irreplaceable key material for the main structure, functional structure and protective structure of satellites and spacecraft. The Special Fiber Division of the Institute of Materials Technology and Engineering of the Chinese Academy of Sciences has long been committed to the research and development of domestic high-performance carbon fiber technology. In February 2016 and March 2018, the company made breakthroughs in the preparation of domestic M55J and M60J high-strength and high-modulus carbon fiber.

Based on the domestic high-strength and high-modulus carbon fiber serial preparation technology, the Special Fiber Division conducted in-depth research on the basic scientific issues of the domestic M55J high-strength and high-modulus carbon fiber microstructure-macro-performance correlation, and found through fiber cross-sectional morphology research. The domestic M55J high modulus carbon fiber has a regular circular cross section, while the Toray M55J carbon fiber has a waist shape (Fig. 1). Further, through the study of the evolution mechanism of fibrous graphite in the high temperature graphitization process, it is found that the high modulus carbon fiber tensile modulus and Raman spectroscopy. There is a certain functional relationship between the D-peak of the disordered structure and the G-peak of the characteristic structure of graphite. The smaller the value of the F-peak and G-peak, the higher the tensile modulus of the fiber, and the higher the tensile strength of the domestic M55J carbon fiber. 4.86GPa, which is significantly higher than the 4.02GPa of Toray M55J carbon fiber. Combined with the difference in performance, it is found that the microstructure of the microcrystalline layer is the key factor affecting the tensile strength of the high modulus carbon fiber. The domestic M55J high modulus The carbon fiber is the same as the Toray M55J carbon fiber graphite microcrystalline layer, but the domestic M55J high modulus carbon fiber has higher graphite crystallite orientation (Fig. 2). DESCRIPTION highly oriented graphite crystallites help to improve the structure of a high modulus carbon fiber tensile strength. The results of this series of studies are published in Composites Part A: Applied Science and Manufacturing. 2018, 112: 111-118; Journal of Raman Spectroscopy, 2019, doi.org/10.1002/jrs. 5569.

In addition, based on the basic research on the influence of polyacrylonitrile pre-oxidized fiber density and element content, low-temperature two-stage graphitization on the performance of high-mode carbon fiber, the Special Fiber Division recently applied for 5 national invention patents (application number 201810536653) .x;201810431103.1;201810431101.2;201810339670.4;201810311440.7), 2 authorized utility model patents (201820826573.3; 201102536161.6).

The research work of this series was funded by the Key Project of the Equipment Development Department (Finance Project) (6140922010103) and the Chinese Academy of Sciences Pilot Project (XDA17020405).