Polyacrylonitrile preoxidized fiber skin-core structure detection method

A technology of pre-oxidized fiber and polyacrylonitrile, which is applied in the direction of measuring devices, test sample preparation, sampling, etc., can solve the problems of poor curing effect of collodion liquid, rough hole wall, affecting accuracy, etc., and achieves guaranteed treatment Efficiency and effect, avoiding fiber lodging, and ensuring the effect of flatness

Inactive Publication Date: 2017-04-26
SHANXI INST OF COAL CHEM CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Zhu Xiaolong (CN103575754A) adopted SEM observation and measurement method after sulfuric acid solution etching. In this method, the pre-oxidized fiber was first solidified with collodion solution, then cut along the fixture with a blade, and then etched with normal temperature sulfuric acid solution. The toughness of the fiber is relatively high, and the curing effect of the collodion solution is poor. When cutting with a blade, the fiber is prone to lodging and the cross section is uneven; Not smooth, affecting the accuracy of observation and core diameter measurement results
Qi Mingzhi (CN101825558A) used the optical density method, but this method first needs to go through strict ultra-thin section processing with a thickness of about 50-1500nm, and needs to ensure that the cut surface is flat and free of knife marks, and secondly, the obtained pictures need to be professionally analyzed. The data can be obtained, the overall processing steps are complicated, and the operation is difficult

Method used

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  • Polyacrylonitrile preoxidized fiber skin-core structure detection method
  • Polyacrylonitrile preoxidized fiber skin-core structure detection method
  • Polyacrylonitrile preoxidized fiber skin-core structure detection method

Examples

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Effect test

Embodiment 1

[0022] 1g3cm long 1KPAN pre-oxidized short fiber is immersed in a flask filled with sulfuric acid solution, the concentration of sulfuric acid solution is 20wt%, the sulfuric acid solution is heated to boiling, and the treatment time is 2h. Stir and wash the treated pre-oxidized short fibers in a beaker filled with deionized water until neutral to remove residual sulfuric acid solution. After filtering with filter paper, collect the pre-oxidized short fibers in a watch glass, put Dry in a blast oven at 120°C for 1.5h, and cool to room temperature naturally in a desiccator. Take the treated pre-oxidized short fiber, place the pre-oxidized short fiber in parallel, wrap the pre-oxidized short fiber tightly with strip-shaped double-sided conductive tape, and then quickly cut off the two ends of the wrapped tape with a blade, Keep a 0.5cm long section in the middle, stick one end of it firmly with double-sided conductive tape and stand it upright on the SEM sample stage, use SEM to...

Embodiment 2

[0028] 1g of 3cm long 3KPAN pre-oxidized fiber short filaments are immersed in a flask filled with sulfuric acid solution, the concentration of sulfuric acid solution is 40wt%, and the sulfuric acid solution is heated to boiling for 0.8h. Stir and wash the treated pre-oxidized short fibers in a beaker filled with deionized water until neutral to remove residual sulfuric acid solution. After filtering with filter paper, collect the pre-oxidized short fibers in a watch glass, put Dry in a blast oven at 120°C for 1.5h, and cool to room temperature naturally in a desiccator. Take the processed pre-oxidized short fiber, place the short pre-oxidized fiber in parallel, wrap the short pre-oxidized fiber tightly with strip-shaped double-sided conductive tape, and then quickly cut off the two ends of the wrapped tape with a blade , keep a 0.5cm-long section in the middle, stick one end of it firmly with double-sided conductive tape and stand it upright on the SEM sample stage, use SEM t...

Embodiment 3

[0034] 1g of 3cm long 6KPAN pre-oxidized fiber short filaments are immersed in a flask filled with sulfuric acid solution, the concentration of sulfuric acid solution is 60wt%, the sulfuric acid solution is heated to boiling, and the treatment time is 0.1h. Stir and wash the treated pre-oxidized short fibers in a beaker filled with deionized water until neutral to remove residual sulfuric acid solution. After filtering with filter paper, collect the pre-oxidized short fibers in a watch glass, put Dry in a blast oven at 120°C for 1.5h, and cool to room temperature naturally in a desiccator. Take the treated pre-oxidized short fiber, place the pre-oxidized short fiber in parallel, wrap the pre-oxidized short fiber tightly with strip-shaped double-sided conductive tape, and then quickly cut off the two ends of the wrapped tape with a blade, Keep a 0.5cm long section in the middle, stick one end of it firmly with double-sided conductive tape and stand it upright on the SEM sample ...

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Abstract

A polyacrylonitrile preoxidized fiber skin-core structure detection method includes impregnating preoxidized short fibers in a sulfuric acid solution, heating to be boiling, performing refluxing treatment for 0.1-2 hours, washing the treated sample to be neutral, drying the washed sample, and cooling the dried sample to the room temperature; scanning the sections of the treated preoxidized short fibers by an SEM, storing pictures, subjecting the pictures to fiber diameter and core diameter measurement by SEM measuring software, averaging, and determining the core proportion. The polyacrylonitrile preoxidized fiber skin-core structure detection method is simple and convenient to operate and capable of detecting a PAN (polyacrylonitrile) preoxidized fiber skin-core structure accurately and quickly.

Description

technical field [0001] The invention belongs to a method for detecting the homogenization degree of polyacrylonitrile (PAN) pre-oxidized fibers, in particular to a method for detecting the sheath-core structure of pre-oxidized fibers. Background technique [0002] Carbon fiber has excellent properties such as high specific strength, high specific modulus, corrosion resistance, high temperature resistance, friction resistance, thermal conductivity, and electrical conductivity. It has a wide range of applications in aerospace, sports, construction, automobiles, new energy and other fields. In the preparation process of PAN-based carbon fibers, pre-oxidation treatment is one of the key links affecting the performance of carbon fibers. It is a non-plastic heat-resistant trapezoidal structure. In this process, due to the rapid cyclization of the outer layer of the fiber to form a dense structure, which hinders the transmission of oxygen to the inside along the fiber radial direc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N23/225G01N1/28G01N1/44
CPCG01N23/2251G01N1/286G01N1/44G01N2001/2873
Inventor 吕春祥孙同庆李永红邵伟
Owner SHANXI INST OF COAL CHEM CHINESE ACAD OF SCI
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