In recent years, due to the low price of polyester fiber, it has become increasingly widespread in the Russian textile industry. This has led to a gradual reduction in the use of polyacrylonitrile fibers in textile products, and polyacrylonitrile fibers have been used more for the production of carbon fibers.
Russian scientists studied Russian samples of polyacrylonitrile fibers used in the preparation of carbon fibers, their filament formation processes, different components of acrylonitrile copolymers, and the types of solvents used. Studies using X-ray photography, differential Scanning calorimetry, pyrolysis yield analysis, the results show that:
The copolymer composition does not actually affect the crystallization process of the polyacrylonitrile fibers;
The difference in the solvent has a significant effect on the crystal size of the precipitated polymer. The crystals of the polyacrylonitrile fibers formed in the organic solvent are 60-66% larger than the crystals of the polyacrylonitrile fibers formed in the saline solution.
The temperature data analysis and heat capacity index analysis of the sample in the vitrification section showed that the polyacrylonitrile fiber polymer chain formed by the salt water solution has a small heat capacity, a large rigidity of its segment, and a rigidity of its amorphous region, exceeding the organic solvent. Formed polyacrylonitrile fiber polymer chains.
When the fibers were heated, thermogravimetric analysis demonstrated that the mass loss of the three samples began at 287°C, 245°C, and 241°C, respectively. At 292°C, 250°C, and 248°C, respectively, the mass loss is the fastest. At 300°C, 257°C, and 259°C, respectively, the moment of maximum mass loss ends. At 400°C, the total mass changes were 35.5%, 23.1%, and 24.5% for the three samples, respectively.
The change in the gravimetric gravimetric data reveals that when the fiber is heated, the temperature after the start of the mass loss is reduced, so that the quality loss of the PAN precursor during oxidation can be reduced accordingly.
Russian scientists studied Russian samples of polyacrylonitrile fibers used in the preparation of carbon fibers, their filament formation processes, different components of acrylonitrile copolymers, and the types of solvents used. Studies using X-ray photography, differential Scanning calorimetry, pyrolysis yield analysis, the results show that:
The copolymer composition does not actually affect the crystallization process of the polyacrylonitrile fibers;
The difference in the solvent has a significant effect on the crystal size of the precipitated polymer. The crystals of the polyacrylonitrile fibers formed in the organic solvent are 60-66% larger than the crystals of the polyacrylonitrile fibers formed in the saline solution.
The temperature data analysis and heat capacity index analysis of the sample in the vitrification section showed that the polyacrylonitrile fiber polymer chain formed by the salt water solution has a small heat capacity, a large rigidity of its segment, and a rigidity of its amorphous region, exceeding the organic solvent. Formed polyacrylonitrile fiber polymer chains.
When the fibers were heated, thermogravimetric analysis demonstrated that the mass loss of the three samples began at 287°C, 245°C, and 241°C, respectively. At 292°C, 250°C, and 248°C, respectively, the mass loss is the fastest. At 300°C, 257°C, and 259°C, respectively, the moment of maximum mass loss ends. At 400°C, the total mass changes were 35.5%, 23.1%, and 24.5% for the three samples, respectively.
The change in the gravimetric gravimetric data reveals that when the fiber is heated, the temperature after the start of the mass loss is reduced, so that the quality loss of the PAN precursor during oxidation can be reduced accordingly.
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