Untitled

Zlatoustova, L. A.; Смирнова, В. Н.; Медведев, В. А.; Serkov, A. T.

doi:10.1023/a:1020571131832

Cited by 7 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure shows the HRTEM morphology of the PAN fiber longitudinal ultrathin section. The pore structures were unevenly distributed in the PAN Fiber S1 [Figure (a)], which were formed due to the removal of the residual DMSO solvent from the fibers leaving behind open pores, and originated from the coagulation process . The size and number of the pores increased in the PAN Fiber S2 [Figure (b)] due to the removal of a large amount of the DMSO solvents from nascent fibers in the coagulation bath.…”

Section: Resultsmentioning

confidence: 99%

“…They were generated when the fibril backbone were formed by phase separation during coagulating process. 14,30 The surface was smoother and denser in the PAN Fibers S3-S5 [ Figure 4(c-e)]. The reduction of surface defects was conducive to improving the mechanical properties of PAN fibers.…”

Section: Evolution Of the Pore Structures Of The Pan Fibersmentioning

confidence: 97%

“…The pore structures were unevenly distributed in the PAN Fiber S1 [ Figure 3(a)], which were formed due to the removal of the residual DMSO solvent from the fibers leaving behind open pores, and originated from the coagulation process. 30 The size and number of the pores increased in the PAN Fiber S2 [ Figure 3(b)] due to the removal of a large amount of the DMSO solvents from nascent fibers in the coagulation bath. After densifying process, the number and sizes of pores decreased distinctly in the PAN Fiber S3 [ Figure 3(c)], which might be resulted by the pore collapse and fibril movement.…”

Section: Evolution Of the Pore Structures Of The Pan Fibersmentioning

confidence: 99%

See 2 more Smart Citations

Correlation between fibril structures and mechanical properties of polyacrylonitrile fibers during the dry‐jet wet spinning process

Gao

Jiang

Wang

et al. 2018

J of Applied Polymer Sci

View full text Add to dashboard Cite

The high quality polyacrylonitrile (PAN) fibers, which were used to manufacture the high performance carbon fibers, were prepared by the dry‐jet wet spinning process. The fiber samples were treated by using the ultrathin sectioning and solution etching methods. Subsequently, the changes of the fibril structures and mechanical properties were investigated by utilizing scanning electron microscopy, high‐resolution transmission electron microscopy and mechanical tester. The fiber titer and diameters, the amount of the pores decreased during the spinning process. The microfibrils were oriented along the fiber axis to form the fiber backbone in PAN fibers. Furthermore, the microfibrils with small size were incorporated into the large fibrils and some fold chains formed the interfibril transverse joint bridges to reinforce the connection of the fibril elements. The fibrils served as self‐reinforcing element to efficiently resist the cracks propagation and dissipate much energy to increase the tensile strength and initial modulus. Consequently, the PAN precursor fibers with the homogeneous, compact, well‐oriented, and closely interlinked fibrils, presented high tensile strength and initial modulus. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47336.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Evolution Of the Pore Structures Of The Pan Fibersmentioning

confidence: 97%

Section: Evolution Of the Pore Structures Of The Pan Fibersmentioning

confidence: 99%

See 1 more Smart Citation

Correlation between fibril structures and mechanical properties of polyacrylonitrile fibers during the dry‐jet wet spinning process

Gao

Jiang

Wang

et al. 2018

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…All of this negatively affects the quality of the final carbon fibre. When the precipitator content decreases, the porosity of the PAN fibre decreases [3], which results in CF with high strength and elasticity. However, decreasing the precipitator content below a certain limit is again accompanied by an increase in the porosity and a decrease in the quality of the CF.…”

mentioning

confidence: 99%

“…Repeated wetting and drying of the fibre decrease the porosity to 20 arb. units [3]. The porosity can be additionally reduced to 10-15 arb.…”

mentioning

confidence: 99%

Improvement of Manufacturing Technology for Ultrastrong and High-Modulus Carbon Fibres

et al. 2005

Self Cite

View full text Add to dashboard Cite

1. The quality of CF, their strength and modulus of elasticity in particular, can be increased by the following methods: reducing the porosity of the initial PAN fibres by selecting the optimum conditions for spinning, plasticization drawing, finishing, and drying; decreasing the nonuniformity of the fibre diameter due to suppression of deformation resonance during spinning by selecting the jet formation and hardening conditions; decreasing the fibril and crystallite size by reducing the precipitator and solvent concentration gradient in the precipitation zone (spinning into mild baths); creating optimum conditions for mesophase self-ordering of the material at 450-550°C during precarbonization; increasing the cohesive energy by increasing the density to 1.8-2.1 g/cm 3 . 2. Replacing convective tempering of PAN twists in thermooxidative treatment by conductive tempering reduces the treatment time by 3-4 times.Carbon fibres (CF) made from polyacrylonitrile (PAN) copolymers are the most widely used CF. This type of fibre has a set of properties (high strength and modulus of elasticity, dimensional stability, resistance to corrosion, low density) that predetermined their use in high-tech industries such as rocket-space, aviation and atomic, ship building, and production of high-quality sporting goods. However, the production volumes of these fibres is still comparatively small, 12-15,000 tons a year, which is due to imperfect technology and equipment that do not ensure the required level of quality indexes, production economy, and respect of environmental requirements. Some scientific premises and technical solutions on improving PAN CF manufacturing technology are examined below.As for the quality indexes, together with the CF manufacturing technology, many investigators [1] believe that the properties of the initial PAN fibre, particularly its defectiveness, degree of orientation, and microfibril structure are of determining importance here.Of the large number of defects characteristic of wet-spun PAN fibres, we distinguish the two that most strongly affect the quality of CF: porosity and nonuniformity of the filament diameter. The negative effect of porosity on the quality of CF is manifested in two ways. First, since the features of the structure of the initial PAN fibre are preserved in the structure of the CF, the porosity is also preserved, causing nonuniformity of internal stresses and brittleness in the CF. The second negative mechanism of the effect of porosity is the decrease in the thermal stability of PAN fibre, i.e., the lower value of the maximum attainable limiting temperature of thermal decomposition of the polymer. Pores serve as nuclei or centers of the onset of thermolysis of PAN fibre and do not allow attaining the temperature of 500-550°C in rapid heating required for mesophase rearrangement of the structure of the oxidized fibre during carbonization without intensive decomposition [2].The appearance of pores in PAN fibre is predetermined by the nature of wet spinning, where the volume of solve...

show abstract

Producing high‐quality precursor polymer and fibers to achieve theoretical strength in carbon fibers: A review

Kaur

Millington

Smith

2016

J of Applied Polymer Sci

View full text Add to dashboard Cite

ABSTRACT:The precursor fiber quality has a large impact on carbon fiber processing in terms of its performance, production yield, and cost. Polyacrylonitrile precursor fibers have been used commercially to produce strong carbon fibers with average tensile strength of 6.6 GPa. There is a scope to improve the average tensile strength of carbon fibers, since only 10% of their theoretical strength has been achieved thus far. Most attempts to increase the tensile strength of carbon fibers have been made during the conversion of precursor fiber to carbon fiber. This review highlights the potential opportunities to enhance the quality of the polyacrylonitrile-based precursor fiber during polymer synthesis, spinning, and postspinning. These high-quality precursor fibers can lead to new generation carbon fibers with improved tensile strength for high-performance applications.

show abstract

Untitled

Cited by 7 publications

References 0 publications

Correlation between fibril structures and mechanical properties of polyacrylonitrile fibers during the dry‐jet wet spinning process

Correlation between fibril structures and mechanical properties of polyacrylonitrile fibers during the dry‐jet wet spinning process

Improvement of Manufacturing Technology for Ultrastrong and High-Modulus Carbon Fibres

Producing high‐quality precursor polymer and fibers to achieve theoretical strength in carbon fibers: A review

Contact Info

Product

Resources

About