EFFICIENCY OF CARBON FIBER EXTRACTION BY LOW-TEMPERATURE SOLVOLYSIS

The paper presents the results of a comprehensive study of the effect of the structure of carbon fibers and the type of the initial polymer composite on the quality of the reclaimed fiber obtained by low-temperature solvolysis. The characteristics of the initial and reclaimed carbon fibers were analyzed using a wide range of experimental methods, including structural (X-ray diffraction analysis, scanning electron microscopy, Raman spectroscopy) and thermal studies. Solvolysis was carried out in a mixture of H2SO4 (conc.):H2O2 (conc.): H2O in a mass ratio of 2.5:3:1, respectively, at the boiling point of the solution. The recycling time was 1 h with a solution change every 20 min. The results of electron microscopy showed that, regardless of the type of polymer system, there are practically no binder residues on the surface of the fibers. Using thermal analysis, it was shown that the main mass loss of all samples of the reclaimed fiber occurs at temperatures above 600 ° C. Despite the fact that origin fibers with a smooth surface show greater thermal stability than those with a relief structure (mass loss temperature of 5% - 650°C and 620°C, respectively), extracted fibers based on the same brand have lower mass loss values. In order to assess the destructive effect of the solvolysis solution during extraction, the structural changes in the carbon fiber surface were studied by the method of Raman spectroscopy. The degree of graphitization was estimated by the ratio of the peak areas D (defective component) and G (graphite component). A decrease in the degree of graphitization after solvolysis was shown for both types of carbon fibers. The crystallite sizes of carbon fiber samples were determined by X-ray diffraction analysis. The results showed a decrease in the apparent thickness of Lc and the transverse size of the La crystallite for all samples after solvolysis. For citation: Trukhinov D.K., Lebedeva E.A., Ivanova E.V., Istomina T.S., Astaf’eva S.A. Efficiency of carbon fiber extraction by low-temperature solvolysis. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 4. P. 59-66. DOI: 10.6060/ivkkt.20256804.7162.