In comparison with pan based carbon fiber cf pan, mesophase pitch based carbon fiber cf mp has higher thermal conductivity due to fewer lattice defects, higher preferred orientation, and larger graphite crystallite size 15,16. Effect of liquid crystalline texture of mesophase pitches. Chargedischarge characteristics of mesophasepitchbased. Investigation of the degradation of pitchbased carbon. The term mesophase pitch1 with thermotropic properties has been introduced recently. Carbon fibers attract considerable attention because they provide a high tensile strength and modulus with low weight. The fibres with high strength and elongation to failure were found to be composed of turbostratic carbon structure, which was. The preparation method involved thermal condensation, vacuum treatment, and annealing treatment. Four kinds of mesophasepitchbased carbon fibers with different textures in their crosssections were used as host materials for graphite intercalation compounds with sulfuric acid. Petroleum mesophase pitch based carbon fibers are produced by melt spinning of pitch precursors.
The conoco carbon fiber is made from a higher performing petroleum pitch called mesophase. Mesophase pitchbased carbon fiber and its composites. Mesophase pitch based carbon fiber spinning through a filter assembly and the microstructure evolution mechanism. The meltblown fibers are continuous fibers which are collected into a fibrous web form, and the diameter of the filaments is attenuated by the flow rate of air. Carbon fiber is also available by oilcoal pitch based carbon fiber, mesophase pitch based carbon fiber, isotropic pitch based carbon fiber, pan based carbon fiber, rayon based carbon fiber and gas phase based carbon fibers. The pitch was pelletized before spinning because the pitch powder can agglomerate in the feed throat of a screw extruder, which can render uniform heating difficult. Pan based carbon fibers pitch based carbon fibers mesophase pitch based carbon fibers isotropic pitch based carbon fibers rayon based carbon fibers gasphasegrown carbon fibers 12. Pdf meltblown solvated mesophase pitchbased carbon fibers. An advantage in the production of pitch carbon fibers over pan carbon fibers is that pitch carbon fibers do not require constant tension on the fibers at all processing stages.
Pdf preparation and evaluation of isotropic and mesophase pitch. Semantic scholar extracted view of mesophase pitch based carbon fiber and its composites. The resultant carbon fibers have a fibrillar microtexture and exhibit exceptional tensile strength. Mesophase pitch is made by polymerizing isotropic pitch to a higher molecular weight. Semantic scholar extracted view of mesophase pitchbased carbon fiber and its composites. Carbon fibers made by carbonizing precursor fibers are categorized according to the type of precursor fibers used, such as pan based carbon fibers, pitch based carbon fibers and rayon based carbon fibers. Low cost carbon fiber technology development for carbon fiber composite applications april 2012. Pan, pitch and mesophase based carbon fibers is plotted in figure 2. Pan polyacrylonitrile is a precursor thermoplastic polymer derived from oil or coal that is spun i. A comprehensive study on the oxidative stabilization of. Mesophase pitch preparation requires aromatic feed stock, process for polymerizing the. Carbon fiber technology facility merlin theodore, phd pi director, carbon fiber technology facility.
Disregarding the wt % solvents in the spun fibers, the carbon yield of the resulting cfs is 86 wt %. Imtech carbon and insulation materials technology group high thermal conductivity, mesophase pitchderived carbon foams by dr. Thus, perhaps they would be more accurately termed isotropic pitch based and mesophase pitch based carbon fibers. Mesophase pitch is obtained by heat treatment, as a result of which chemical reactions occur with a change in structural characteristics the formation of mesophases. To reveal the fracture difference of carbon fiber between the pressing roller and the grooved wheel technique, comparative investigation of failure behavior between a single carbon fiber also simplified as a filament with flexible support and with nonsupport was performed in offaxis transverse cutting using a customdesigned fixture. Pdf studies on mesophasepitchbased carbon fibers, part.
Conventional syntheses rely on blending polyacrylonitrile with sacrificial additives, which macrophaseseparate and result in poorly controlled pores after pyrolysis. Typical processing sequence for pan based carbon fibers major cost elements precursor 50% conversion 40%. It needs to be emphasized that carbonaceous precursors for the preparation of highperformance mesophase pitch are very crucial. The effects of oxidation treatments and surface coating on the surface properties of the solvated mesophase pitchbased carbon fiber cf are investigated to improve the mechanical properties of. Preparation and characterization of pitchbased carbon fibers. Pdf structural characterization of milled mesophase. Mesophase pitch based carbon fibers were heattreated at high temperatures 2600 or 2800 and examined as anodes for lithium secondary batteries. Needle coke, carbon fibers, mesophase pitch mesophase microspheres, carbon fibers, foams coal charcoal activated carbons coal tar pitch ctp polymers and prepolymers pan resins polyimides biomass carbon fibers. The purpose of this study is to investigate the potential of using a pelletized pitch in a continuous process for the economical preparation of largescale pitch based carbon fibers. Ma september 1983 a private report by the process economics program menlo park, california 94025. Unlike carbon nanotubes, which were previously studied for modifying fiber microstructure, cb represents a significantly lower cost alternative making it more favorable for industrial application.
Effect of liquid crystalline texture of mesophase pitches on. Most of the previous studies of pitchbased cfs have been conducted by. The effects of carbon black cb on the microstructural development within mesophase pitch based carbon fibers are reported. Here, we use block copolymer microphase separation. Pitchbased carbon and graphite fibers are made by heating coaltar pitch for up to 40 h at 800f, forming a highviscosity liquid with a high degree of molecular order known as a mesophase. Relation between the compressive strength and tensile modulus of carbon difference in the compressive failure mechanism. The effect of the spinning conditions on the structure of mesophase pitch based carbon fibers by taguchi method zhao jiang, ting ouyang, xiangdong yao, and youqing fei carbon letters, 2016, volume 19, page 89. Structure of mesophase pitchbased carbon fibres springerlink.
Ablation behavior of the siccoated threedimensional highly. Translation find a translation for mesophase pitch based carbon fibers in other languages. Oil is also multicomponent with some components having more carbon molecule than others. Potentially lowcost continuous carbon fibers are produced from solvated mesophase pitch through a patented meltblowing process. Cftf successfully developed low, standard, and intermediate carbon fiber using textile based precursor. Spinning and carbonization of mesophase pitch fiber ornl pi james klett. Preparation and evaluation of isotropic and mesophase pitchbased carbon fibers using the pelletizing and continuous spinning process. Block copolymerbased porous carbon fibers science advances. The synthetic carbon industry had its official beginning in 1886 with the creation of the national carbon company. All three materials passed the projects strength goals for phase one of the project, collins says. Jul 12, 2019 spinnable mesophase pitch precursor containing more than 98% mesophase content was successfully prepared from fccdo fluid catalytic crackingdecant oil without hydrogenation or catalytic reaction. Mesophase pitch is a discotic liquid crystalline material. Carbon fibers have several advantages including high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion.
These features are visible in the sem micrograph in fig. Apr 02, 2019 advanced carbon products olive hill, ky. Mesophase pitch based carbon fibers have a higher tensile modulus than pan, while the tensile strength of mesophase pitch carbon fibers are much lower than thatofpanbowever,the tensile strength of a carbon fiber depends on its elongation which, in turn, is determined by the degree of defects. The thermal conductivities of several of the hybrid the improved thermal conductivity of our monoliths is attributed to the bonding between the fibers and the incorporation of high thermal conductivity, mesophase pitch derived carbon fibers. Meltblown solvated mesophase pitchbased carbon fibers. The structure and properties of carbon fiber based. The coal and crude oil produced pitch based carbon fiber, while the biomass produced pan based fiber. Carbon fibers or carbon fibres alternatively cf, graphite fiber or graphite fibre are fibers about 510 micrometres in diameter and composed mostly of carbon atoms. Pdf structural characterization of milled mesophase pitch. Mesophase pitchbased activated carbon fibers which are obtained by milling infusibilized mesophase pitch fibers, as they are or after carbonizing at a temperature of 350 to 1,000 c. View academics in mesophase pitch based carbon fibers on academia.
Of these carbon fibers, pan based carbon fibers have become the most widely used form of carbon fiber. Unlike carbon nanotubes, which were previously studied for modifying. However, the control over their porosity remains challenging. High thermal conductivity, mesophase pitchderived carbon foams. Structureproperty relationship of nanomodified mesophase pitch based carbon fibers a dissertation presented to the graduate school of clemson university in partial fulfillment of the requirements for the degree doctor of philosophy chemical engineering by rebecca marie alwaycooper december 2014 accepted by. Mesophase pitch preparation requires aromatic feed stock, process for polymerizing the molecules, and separating out of uncreated feed molecules. Mesophase pitch based carbon fibers firstly reported by singer in 1978 are the most successful highend product for the development and application of carbonaceous mesophase, which are derived from spinnable mesophase pitch by melt spinning, oxidative stabilization, and carbonization and.
The structure of five samples of commercially available carbon fibres with ultrahigh modulus produced from mesophase pitch was studied by the complementar. Torsional tests of single filament had been used to measure the torsional properties of both pan. Mesophase pitch based carbon fibres highperformance fibres are made from mesophase pitch. Mesophase pitchbased carbon fibres highperformance fibres are made from mesophase pitch. Currently, carbonaceous mesophases can be produced with a range of solubilities, in e. Pan, pitch and mesophasebased carbon fibers is plotted in figure 2. Pitch precursorbased carbon fibers request pdf researchgate. Four kinds of mesophase pitchbased carbon fibers with different textures in their crosssections were used as host materials for graphite intercalation compounds with sulfuric acid. Pitchbased carbon fiber an overview sciencedirect topics. Pitchbased carbon and graphite fibers are made by heating coaltar pitch for up to 40 h at 800f, forming a highviscosity liquid with a high degree of molecular. The structure of five samples of commercially available carbon fibres with ultrahigh modulus produced from mesophase pitch was studied by the complementary techniques of high resolution electronmicroscopy, xray diffraction and transverse magnetoresistance effect.
The effect of tex ture on lithium intercalation and deintercalation behavior is discussed. Carbon fiber production carbon fiber is currently produced in relatively limited quantities mostly via two manufacturing processes. Research of developing coal, oil into lowcost carbon. Pitch based fibers of high modulus typically deform by a shear mechanism, with kink bands formed on a. Published monthly by the genesis of product making pitch. The company is devoted to the research and development of mesophase pitch base carbon fiber and its composites, pdcpdrim resin and other products. In particular, pitch based carbon fibers have the inherent benefits of a. High thermal conductivity, mesophase pitchderived carbon. Mesophase pitchbased carbon fiber is expected to exhibit high tensile properties due to its high oriented molecular structure and high crystallinity of graphite. Four types of carbon fibers were used whose crosssectional views are. It can be formed as an intermediate phase during thermolysis pyrolysis of an isotropic molten pitch or by development from pitch fractions prepared by selective. In this graphite crystalline structures are arranged in a manner that it gives fibrous material. International symposium on noncrystalline order in polymers, naples, italy, 1985052719850530. Mesophase pitch and its carbon fibers pure and applied chemistry.
Even with a huge difference in the thermal energy used, the carbon fibers prepared using the pelletizedpitchbased continuous process had. Research of developing coal, oil into lowcost carbon fiber. The structural evolution and properties of the fibers are characterized by various analytical methods. Preparation and evaluation of isotropic and mesophase pitch. Carbonaceous mesophase is a liquidcrystalline state of pitch which shows the optical birefringence of disclike discotic nematic liquid crystals. In the past, more economical isotropic pitch fibers did not provide a sufficiently broad range of properties.
Mesophase pitchbased carbon fibers have a higher tensile modulus than pan, while the tensile strength of mesophase pitch carbon fibers are much lower than thatofpanbowever,the tensile strength of a carbon fiber depends on its elongation which, in turn, is determined by the degree of defects. Carbon fibers have high surface areas and rich functionalities for interacting with ions, molecules, and particles. Mesophase pitchderived carbons with high electronic and. Petroleum mesophase pitch based carbon fibers are produced by melt spinning of pitch precursors, followed by stabilization and carbonization. Mesophase pitch carbon fibers have a wide variety of internal structures, such as radial. The resulting carbon fiber exhibited good mechanical performances up to tensile strength of 2. Precursors have a major influence on the properties of carbon fibers. Both series of samples were activated by koh with varying the koh addn. Polyacrylonitrile pan based and pitch based carbon fibers are the most common carbon fibers 14,15. Even with a huge difference in the thermal energy used, the carbon fibers prepared using the. Pan based carbon fibers have a smaller crystal size and exhibit particle like structures, whereas pitch based fibers have a larger crystal size with sheetlike structures.
Each type of fiber, collins says, has different properties making it suitable for particular applications. Pdf meltblown solvated mesophase pitchbased carbon. High performance carbon fibers american chemical society. Two classes of carbon materials with different microstructures were chosen for elec. I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the requirements. Preparation and evaluation of isotropic and mesophase. Even though presently these fibers represent only about 10% of the total carbon fibers produced worldwide, potentially, they could become a lowcost alternative to pan based carbon fibers. Carbon black modification of mesophase pitchbased carbon. Ornl also conducts fiber strength tests and provides data to mit and other team members to improve carbon fiber. Structureproperty relationship of nanomodified mesophase pitch. The structure and properties of carbon fiber based adsorbent. May 09, 2016 the composites industry appears to be on the verge of taking another step in its quest for affordable, highquality carbon fiber. Carbon fibers made from stabilized mesophase pitch, either petroleum. Mesophase pitch rayon lignins polyethylene high strength, moderate modulus high modulus, moderate strength.
Us6118650a mesophase pitchbased activated carbon fibers. Preparation, characterization, and applications of. Comparative investigation of carbon fiber filaments in off. Pitch based carbon and graphite fibers are made by heating coaltar pitch for up to 40 h at 800f, forming a highviscosity liquid with a high degree of molecular order known as a mesophase. I am submitting herewith a thesis written by chang liu entitled mesophase pitch based carbon fiber and its composites. Founded in june 2015, is located in the hightech zone of fushun city. Pdf mesophase pitchbased carbon fiber and its composites. High thermal conductivity, mesophase pitch derived carbon foams by dr. Pitch based carbon fiber nippon graphite fiber corporation, a nippon steel group company, produces pitch based carbon. Investigation of the degradation of pitchbased carbon fibers. Based on the original weight of the spun fibers, carbonized fibers showed a 75 wt % yield.
The purpose of this study is to investigate the potential of using a pelletized pitch in a continuous process for the economical preparation of largescale pitchbased carbon fibers. What is the difference between panbased and pitchbased. The other is an isotropic pitch based carbon fiber ipcf. Structureproperty relationship of nanomodified mesophase. Experimental four types of mesophase pitch based carbon fibers heat. Based on polyacrylonitrile pan current global capacity for pitch based carbon fiber is estimated at about 3,500 metric tons per year. Mesophase pitchbased carbon fibers are known for their excellent thermal and electrical conductivity, high tensile modulus, moderate tensile. Due to the use of the meltblowing process involvin g attenuation via air streams, the diameter of the spun fibers can be attenuated by the flow rate of air streams. Structural characterization of milled mesophase pitch based carbon fibers. They can be prepared at a lowcost because of their qheapraw materials and high carbon yield.
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