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. Pitch based fibers of high modulus typically deform by a shear mechanism, with kink bands formed on a. The melting point for the mesophase pitch is roughly 300 c. Here, we use block copolymer microphase separation. Apr 02, 2019 advanced carbon products olive hill, ky. Oil is also multicomponent with some components having more carbon molecule than others. May 09, 2016 the composites industry appears to be on the verge of taking another step in its quest for affordable, highquality carbon fiber. Pan polyacrylonitrile is a precursor thermoplastic polymer derived from oil or coal that is spun i. Mesophase pitch preparation requires aromatic feed stock, process for polymerizing the. 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. 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. Based on the original weight of the spun fibers, carbonized fibers showed a 75 wt % yield.
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. Ma september 1983 a private report by the process economics program menlo park, california 94025. 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. Mesophase pitch based carbon fiber spinning through a filter assembly and the microstructure evolution mechanism. Translation find a translation for mesophase pitch based carbon fibers in other languages. The conoco carbon fiber is made from a higher performing petroleum pitch called mesophase. Currently, carbonaceous mesophases can be produced with a range of solubilities, in e. Spinning and carbonization of mesophase pitch fiber ornl pi james klett. Us6118650a mesophase pitchbased activated carbon fibers. Effect of liquid crystalline texture of mesophase pitches on. The company is devoted to the research and development of mesophase pitch base carbon fiber and its composites, pdcpdrim resin and other products.
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. Disregarding the wt % solvents in the spun fibers, the carbon yield of the resulting cfs is 86 wt %. Structural characterization of milled mesophase pitch based carbon fibers. Carbon black modification of mesophase pitchbased carbon.
Carbon fiber production carbon fiber is currently produced in relatively limited quantities mostly via two manufacturing processes. Petroleum mesophase pitch based carbon fibers are produced by melt spinning of pitch precursors, followed by stabilization and carbonization. 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. Mesophase pitchbased carbon fibers are known for their excellent thermal and electrical conductivity, high tensile modulus, moderate tensile. Most of the previous studies of pitchbased cfs have been conducted by. A comprehensive study on the oxidative stabilization of. Even with a huge difference in the thermal energy used, the carbon fibers prepared using the pelletizedpitchbased continuous process had. Pan, pitch and mesophase based carbon fibers is plotted in figure 2. Structureproperty relationship of nanomodified mesophase pitch. In this graphite crystalline structures are arranged in a manner that it gives fibrous material. Pdf structural characterization of milled mesophase pitch. The structure and crystal size influence properties like compressive strength, tensile strength, etc.
Torsional tests of single filament had been used to measure the torsional properties of both pan. 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. I am submitting herewith a thesis written by chang liu entitled mesophase pitch based carbon fiber and its composites. 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. Pitch precursorbased carbon fibers request pdf researchgate. High thermal conductivity, mesophase pitchderived carbon foams. High performance carbon fibers american chemical society. Pdf meltblown solvated mesophase pitchbased carbon fibers.
Pdf studies on mesophasepitchbased carbon fibers, part. The term mesophase pitch1 with thermotropic properties has been introduced recently. Experimental four types of mesophase pitch based carbon fibers heat. Chargedischarge characteristics of mesophasepitchbased. Imtech carbon and insulation materials technology group high thermal conductivity, mesophase pitchderived carbon foams by dr. Mesophase pitchbased carbon fibres highperformance fibres are made from mesophase pitch. 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. Pdf meltblown solvated mesophase pitchbased carbon.
Pdf structural characterization of milled mesophase. Preparation and evaluation of isotropic and mesophase pitch. Mesophase pitch rayon lignins polyethylene high strength, moderate modulus high modulus, moderate strength. The resultant carbon fibers have a fibrillar microtexture and exhibit exceptional tensile strength. Typical processing sequence for pan based carbon fibers major cost elements precursor 50% conversion 40%. High thermal conductivity, mesophase pitch derived carbon foams by dr. 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. 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. Mesophase pitch carbon fibers have a wide variety of internal structures, such as radial. Research of developing coal, oil into lowcost carbon. The resulting carbon fiber exhibited good mechanical performances up to tensile strength of 2. Preparation of petroleumbased mesophase pitch toward cost.
Carbon fibers attract considerable attention because they provide a high tensile strength and modulus with low weight. However, the control over their porosity remains challenging. View academics in mesophase pitch based carbon fibers on academia. Carbon fiber technology facility merlin theodore, phd pi director, carbon fiber technology facility. Semantic scholar extracted view of mesophase pitch based carbon fiber and its composites. 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. Four types of carbon fibers were used whose crosssectional views are. 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.
Mesophase pitch is a discotic liquid crystalline material. Pan, pitch and mesophasebased carbon fibers is plotted in figure 2. Unlike carbon nanotubes, which were previously studied for modifying. Each type of fiber, collins says, has different properties making it suitable for particular applications.
The effects of carbon black cb on the microstructural development within mesophase pitch based carbon fibers are reported. The synthetic carbon industry had its official beginning in 1886 with the creation of the national carbon company. Precursors have a major influence on the properties of carbon fibers. Mesophase pitch and its carbon fibers pure and applied chemistry. Investigation of the degradation of pitchbased carbon.
Pdf preparation and evaluation of isotropic and mesophase pitch. Block copolymerbased porous carbon fibers science advances. In particular, pitch based carbon fibers have the inherent benefits of a. Structureproperty relationship of nanomodified mesophase. High thermal conductivity, mesophase pitchderived carbon. Conventional syntheses rely on blending polyacrylonitrile with sacrificial additives, which macrophaseseparate and result in poorly controlled pores after pyrolysis. 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. Pdf mesophase pitchbased carbon fiber and its composites.
All three materials passed the projects strength goals for phase one of the project, collins says. Preparation, characterization, and applications of. Mesophase pitchbased carbon fiber and its composites. International symposium on noncrystalline order in polymers, naples, italy, 1985052719850530. 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. Mesophase pitch based carbon fibres highperformance fibres are made from mesophase pitch. To evaluate the benefits of using pitch pellets in the continuous carbon fiber spinning process, isotropic and mesophase pitch fibers were prepared by both the conventional batch process using pitch powder and continuous process using pitch pellets. Mesophase pitch preparation requires aromatic feed stock, process for polymerizing the molecules, and separating out of uncreated feed molecules. 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. Based on polyacrylonitrile pan current global capacity for pitch based carbon fiber is estimated at about 3,500 metric tons per year. Preparation and evaluation of isotropic and mesophase pitchbased carbon fibers using the pelletizing and continuous spinning process. Ornl also conducts fiber strength tests and provides data to mit and other team members to improve carbon fiber. It needs to be emphasized that carbonaceous precursors for the preparation of highperformance mesophase pitch are very crucial.
Ablation behavior of the siccoated threedimensional highly. Structure of mesophase pitchbased carbon fibres springerlink. 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. 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. Founded in june 2015, is located in the hightech zone of fushun city. 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. Carbon fibers made from stabilized mesophase pitch, either petroleum. The structure and properties of carbon fiber based.
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. In the past, more economical isotropic pitch fibers did not provide a sufficiently broad range of properties. Effect of liquid crystalline texture of mesophase pitches. Carbonaceous mesophase is a liquidcrystalline state of pitch which shows the optical birefringence of disclike discotic nematic liquid crystals.
These features are visible in the sem micrograph in fig. 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. Research of developing coal, oil into lowcost carbon fiber. The other is an isotropic pitch based carbon fiber ipcf.
Pitch based carbon fiber nippon graphite fiber corporation, a nippon steel group company, produces pitch based carbon. Pitchbased carbon fiber an overview sciencedirect topics. The coal and crude oil produced pitch based carbon fiber, while the biomass produced pan based fiber. Even with a huge difference in the thermal energy used, the carbon fibers prepared using the. Mesophase pitch is made by polymerizing isotropic pitch to a higher molecular weight. Wri is working with ramaco carbon for converting coal pitch compounds that are then spun into carbon fibers by team members at ornl. The structure and properties of carbon fiber based adsorbent. 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. Published monthly by the genesis of product making pitch. Preparation and characterization of pitchbased carbon fibers. Mesophase pitch based carbon fibers were heattreated at high temperatures 2600 or 2800 and examined as anodes for lithium secondary batteries. Petroleum mesophase pitch based carbon fibers are produced by melt spinning of pitch precursors. Semantic scholar extracted view of mesophase pitchbased carbon fiber and its composites. 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.
The structural evolution and properties of the fibers are characterized by various analytical methods. What is the difference between panbased and pitchbased. Relation between the compressive strength and tensile modulus of carbon difference in the compressive failure mechanism. 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. Polyacrylonitrile pan based and pitch based carbon fibers are the most common carbon fibers 14,15. Of these carbon fibers, pan based carbon fibers have become the most widely used form of carbon fiber. They can be prepared at a lowcost because of their qheapraw materials and high carbon yield. Carbon fibers have high surface areas and rich functionalities for interacting with ions, molecules, and particles. Comparative investigation of carbon fiber filaments in off.
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. Mesophase pitchbased carbon fiber is expected to exhibit high tensile properties due to its high oriented molecular structure and high crystallinity of graphite. 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. 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. 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. Mesophase pitchderived carbons with high electronic and. 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. Four kinds of mesophasepitchbased carbon fibers with different textures in their crosssections were used as host materials for graphite intercalation compounds with sulfuric acid. The effect of tex ture on lithium intercalation and deintercalation behavior is discussed. Thus, perhaps they would be more accurately termed isotropic pitch based and mesophase pitch based carbon fibers. 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. The structure of five samples of commercially available carbon fibres with ultrahigh modulus produced from mesophase pitch was studied by the complementar. 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.
Cftf successfully developed low, standard, and intermediate carbon fiber using textile based precursor. The preparation method involved thermal condensation, vacuum treatment, and annealing treatment. Low cost carbon fiber technology development for carbon fiber composite applications april 2012. Investigation of the degradation of pitchbased carbon fibers. Both series of samples were activated by koh with varying the koh addn. Two classes of carbon materials with different microstructures were chosen for elec. Low cost carbon fiber technology development for carbon. Preparation and evaluation of isotropic and mesophase. Carbon fibers have several advantages including high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion. 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.