Improving Transverse Compressive Modulus of Carbon Fibers during Wet Spinning of Polyacrylonitrile
The performance of carbon fibers depends on the properties of the precursor polyacrylonitrile (PAN) fibers. Stretching of PAN fibers results in improved tensile properties, while potentially reducing its compressive properties. To determine optimization trade-offs, the effect of coagulation conditio...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-06-01
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| Series: | Fibers |
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| Online Access: | https://www.mdpi.com/2079-6439/10/6/54 |
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| author | Sherman Wong Linda K. Hillbrick Jasjeet Kaur Aaron J. Seeber Jurg A. Schutz Anthony P. Pierlot |
| author_facet | Sherman Wong Linda K. Hillbrick Jasjeet Kaur Aaron J. Seeber Jurg A. Schutz Anthony P. Pierlot |
| author_sort | Sherman Wong |
| collection | DOAJ |
| description | The performance of carbon fibers depends on the properties of the precursor polyacrylonitrile (PAN) fibers. Stretching of PAN fibers results in improved tensile properties, while potentially reducing its compressive properties. To determine optimization trade-offs, the effect of coagulation conditions and the stretching process on the compressive modulus in the transverse direction (<i>E<sub>T</sub></i>) was investigated. A method for accurately determining <i>E<sub>T</sub></i> from polymer fibers with non-circular cross-sectional shapes is presented. X-ray diffraction was used to measure the crystallite size, crystallinity, and crystallite orientation of the fibers. <i>E<sub>T</sub></i> was found to increase with decreasing crystallite orientation along the drawing direction, which decreases the tensile modulus in the longitudinal direction (<i>E<sub>L</sub></i>) proportionally to crystallite orientation. Stretching resulted in greater crystallite orientation along the drawing direction for fibers formed under the same coagulation conditions. Increasing the solvent concentration in the coagulation bath resulted in a higher average orientation, but reduced the impact of stretching on the orientation. The relationship between <i>E<sub>T</sub></i> and <i>E<sub>L</sub></i> observed in the precursor PAN fiber is retained after carbonization, with a 20% increase in <i>E<sub>T</sub></i> achieved for a 2% decrease in <i>E<sub>L</sub></i>. This indicates that controlled stretching of PAN fiber allows for highly efficient trading off of <i>E<sub>L</sub></i> for <i>E<sub>T</sub></i> in carbon fiber. |
| first_indexed | 2024-03-09T23:50:43Z |
| format | Article |
| id | doaj.art-763ba66045744460ae88d3837503bc79 |
| institution | Directory Open Access Journal |
| issn | 2079-6439 |
| language | English |
| last_indexed | 2024-03-09T23:50:43Z |
| publishDate | 2022-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fibers |
| spelling | doaj.art-763ba66045744460ae88d3837503bc792023-11-23T16:35:27ZengMDPI AGFibers2079-64392022-06-011065410.3390/fib10060054Improving Transverse Compressive Modulus of Carbon Fibers during Wet Spinning of PolyacrylonitrileSherman Wong0Linda K. Hillbrick1Jasjeet Kaur2Aaron J. Seeber3Jurg A. Schutz4Anthony P. Pierlot5CSIRO Manufacturing, Clayton, VIC 3168, AustraliaCSIRO Manufacturing, Waurn Ponds, VIC 3216, AustraliaCSIRO Manufacturing, Waurn Ponds, VIC 3216, AustraliaCSIRO Manufacturing, Clayton, VIC 3168, AustraliaCSIRO Manufacturing, Waurn Ponds, VIC 3216, AustraliaCSIRO Manufacturing, Waurn Ponds, VIC 3216, AustraliaThe performance of carbon fibers depends on the properties of the precursor polyacrylonitrile (PAN) fibers. Stretching of PAN fibers results in improved tensile properties, while potentially reducing its compressive properties. To determine optimization trade-offs, the effect of coagulation conditions and the stretching process on the compressive modulus in the transverse direction (<i>E<sub>T</sub></i>) was investigated. A method for accurately determining <i>E<sub>T</sub></i> from polymer fibers with non-circular cross-sectional shapes is presented. X-ray diffraction was used to measure the crystallite size, crystallinity, and crystallite orientation of the fibers. <i>E<sub>T</sub></i> was found to increase with decreasing crystallite orientation along the drawing direction, which decreases the tensile modulus in the longitudinal direction (<i>E<sub>L</sub></i>) proportionally to crystallite orientation. Stretching resulted in greater crystallite orientation along the drawing direction for fibers formed under the same coagulation conditions. Increasing the solvent concentration in the coagulation bath resulted in a higher average orientation, but reduced the impact of stretching on the orientation. The relationship between <i>E<sub>T</sub></i> and <i>E<sub>L</sub></i> observed in the precursor PAN fiber is retained after carbonization, with a 20% increase in <i>E<sub>T</sub></i> achieved for a 2% decrease in <i>E<sub>L</sub></i>. This indicates that controlled stretching of PAN fiber allows for highly efficient trading off of <i>E<sub>L</sub></i> for <i>E<sub>T</sub></i> in carbon fiber.https://www.mdpi.com/2079-6439/10/6/54fiber compressionmicrostructure of fibersstructure–property relations |
| spellingShingle | Sherman Wong Linda K. Hillbrick Jasjeet Kaur Aaron J. Seeber Jurg A. Schutz Anthony P. Pierlot Improving Transverse Compressive Modulus of Carbon Fibers during Wet Spinning of Polyacrylonitrile Fibers fiber compression microstructure of fibers structure–property relations |
| title | Improving Transverse Compressive Modulus of Carbon Fibers during Wet Spinning of Polyacrylonitrile |
| title_full | Improving Transverse Compressive Modulus of Carbon Fibers during Wet Spinning of Polyacrylonitrile |
| title_fullStr | Improving Transverse Compressive Modulus of Carbon Fibers during Wet Spinning of Polyacrylonitrile |
| title_full_unstemmed | Improving Transverse Compressive Modulus of Carbon Fibers during Wet Spinning of Polyacrylonitrile |
| title_short | Improving Transverse Compressive Modulus of Carbon Fibers during Wet Spinning of Polyacrylonitrile |
| title_sort | improving transverse compressive modulus of carbon fibers during wet spinning of polyacrylonitrile |
| topic | fiber compression microstructure of fibers structure–property relations |
| url | https://www.mdpi.com/2079-6439/10/6/54 |
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