Academic literature on the topic 'Thermotropic Liquid Crystalline Polymers'

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Journal articles on the topic "Thermotropic Liquid Crystalline Polymers"

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RUDNICKA, IWONA, and ZYGFRYD WITKIEWICZ. "Thermotropic liquid crystalline polymers." Polimery 31, no. 08 (August 1986): 291–97. http://dx.doi.org/10.14314/polimery.1986.291.

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Ujiie, Seiji, and Kazuyoshi Iimura. "Thermotropic Liquid-Crystalline Ionic Polymers." Chemistry Letters 20, no. 3 (March 1991): 411–14. http://dx.doi.org/10.1246/cl.1991.411.

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Sawyer, Linda C. "Structure-property relations of liquid crystalline polymers." Proceedings, annual meeting, Electron Microscopy Society of America 45 (August 1987): 460–63. http://dx.doi.org/10.1017/s0424820100127013.

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Recent liquid crystalline polymer (LCP) research has sought to define structure-property relationships of these complex new materials. The two major types of LCPs, thermotropic and lyotropic LCPs, both exhibit effects of process history on the microstructure frozen into the solid state. The high mechanical anisotropy of the molecules favors formation of complex structures. Microscopy has been used to develop an understanding of these microstructures and to describe them in a fundamental structural model. Preparation methods used include microtomy, etching, fracture and sonication for study by optical and electron microscopy techniques, which have been described for polymers. The model accounts for the macrostructures and microstructures observed in highly oriented fibers and films.Rod-like liquid crystalline polymers produce oriented materials because they have extended chain structures in the solid state. These polymers have found application as high modulus fibers and films with unique properties due to the formation of ordered solutions (lyotropic) or melts (thermotropic) which transform easily into highly oriented, extended chain structures in the solid state.
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Terrien, I., M. F. Achard, G. Félix, and F. Hardouin. "Thermotropic laterally attached liquid crystalline polymers." Journal of Chromatography A 810, no. 1-2 (June 1998): 19–31. http://dx.doi.org/10.1016/s0021-9673(98)00198-8.

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Calundann, G. W., L. F. Charbonneau, and J. P. Shepherd. "Development of thermotropic liquid crystalline polymers." Makromolekulare Chemie. Macromolecular Symposia 51, no. 1 (October 1991): 147–52. http://dx.doi.org/10.1002/masy.19910510112.

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Lenz, R. W. "Characterization of thermotropic liquid crystalline polymers." Pure and Applied Chemistry 57, no. 7 (January 1, 1985): 977–84. http://dx.doi.org/10.1351/pac198557070977.

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Reyes-Mayer, A., B. Alvarado-Tenorio, A. Romo-Uribe, O. Flores, B. Campillo, and M. Jaffe. "Fracture behavior of heat treated liquid crystalline polymers." MRS Proceedings 1485 (2012): 137–42. http://dx.doi.org/10.1557/opl.2013.282.

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ABSTRACTThermotropic polymers are thermally treated in air at temperatures Ta, where ΔT =Ta- Ts→n=40°C, and Ts→n is the solid-to-nematic transition. Samples are extruded thin films of a series of thermotropic random copolyesters termed B-N, COTBP and RD1000. The thermal treatment produces a second endotherm without changing Ts→n for B-N and RD1000. However, for COTBP Ts→n is significantly increased. Regardless of the complex thermal behavior exhibited by the thermotropes, the thermal treatment produces a significant increase in Young's modulus, more than 30% for B-N and over 100% for COTBP. The increase in mechanical modulus is correlated with a thermally-induced fiber-like morphology.
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Windle, Alan. "Liquid Crystalline Polymers." MRS Bulletin 12, no. 8 (December 1987): 18–21. http://dx.doi.org/10.1557/s0883769400066690.

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Not much more than a decade ago, the plastics industry viewed itself as a mature branch of the heavy chemical industry. Its raison d'être was the mass production of four or five main-line polymers, and profits were equated to tonnage output, plant efficiency, and clever downstream processing such as film blowing. The chemistry was essentially simple and the monomer, of course, cheap. There was, however, a spark of new thinking. A trend was developing toward the design and manufacture of more complex, more expensive polymers, with special properties which could command a special price. Such products would sell advanced scientific know-how, not just engineering expertise which could all too easily be exported to the major oil producers in the form of a polymer plant.Designing particular molecules to achieve desired properties is now a major theme of polymer producers. There is a move toward increasing the aromatic content of polymer backbones to achieve greater levels of chemical and thermal stability, while the development of new cross-linking systems remains as chemically intensive as ever. It is, however, the introduction of liquid crystalline polymers which, above all, has exploited the principles of molecular design, while at the same time challenging our understanding in a new area of polymer science.A polymer is “liquid crystalline” where the chains are sufficiently rigid to remain mutually aligned in the liquid phase although the perfect positional periodicity of a crystal is no longer present. In other words there is a long-range orientational order without long-range positional order (Figure 1). Structurally, therefore, the phase is intermediate between a crystal and a liquid leading to the use of the term mesophase. Where the liquid crystalline phase forms on melting the polymer, it is known as thermotropic, but where it is achieved by solvent addition it is called Inotropic. Increasing temperature, or solvent concentration, will eventually lead to the reversion of the liquid crystal phase to the normal isotropic polymer melt.
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Sawyer, Linda C. "Structure hierarchy in liquid crystalline polymers." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 2 (August 1992): 1030–31. http://dx.doi.org/10.1017/s0424820100129784.

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Structure models have been developed for the liquid crystalline polymers (LCPs), showing the existence of fibrillar hierarchies for both the lyotropic aramids and the thermotropic aromatic copolyesters. Hierarchies of structure have also been observed for biological materials. The nature of the smallest nanostructure that aggregates, typically microfibrils, and their interaction, are important in understanding the behavior of the material. This paper discusses the first application of scanning tunneling microscopy (STM) and field emission scanning electron microscopy (FESEM) to image the microfibrils in LCPs, in the 1-10 nm size range, resulting in a new LCP structural model.The structure model proposed earlier, was based on the study of Vectra® thermotropic LCP moldings and extrudates, and Vectran® and Kevlar® fibers. The model resulted from characterization by light microscopy, and transmission and scanning electron microscopy. Recent studies of similar fibers by STM and low voltage FESEM has provided additional insights. Details of single microfibrils and their aggregation into fibrils and macrofibrils was shown.
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Ibidapo, T. Adesanya. "Thermotropic liquid crystalline halatopolymers." Polymer Engineering and Science 30, no. 18 (September 1990): 1146–50. http://dx.doi.org/10.1002/pen.760301806.

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Dissertations / Theses on the topic "Thermotropic Liquid Crystalline Polymers"

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Scribben, Eric Christopher. "Selection of Thermotropic Liquid Crystalline Polymers for Rotational Molding." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/11251.

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Thermotropic liquid crystalline polymers (TLCPs) possess a number of physical and mechanical properties such as: excellent chemical resistance, low permeability, low coefficient of thermal expansion, high tensile strength and modulus, and good impact resistance, which make them desirable for use in the storage of cryogenic fluids. Rotational molding was selected as the processing method for these containers because it is convenient for manufacturing large storage vessels from thermoplastics. Unfortunately, there are no reports of successful TLCP rotational molding in the technical literature. The only related work reported involved the static coalescence of two TLCP powders, where three key results were reported that were expected to present problems that preclude the rotational molding process. The first result was that conventional grinding methods produced powders that were composed of high aspect ratio particles. Secondly, coalescence was observed to be either slow or incomplete and speculated that the observed difficulties with coalescence may be due to large values of the shear viscosity at low deformation rates. Finally, complete densification was not observed for the high aspect ratio particles. However, the nature of these problems were not evaluated to determine if they did, in fact, create processing difficulties for rotational molding or if it was possible to develop solutions to the problems to achieve successful rotational molding. This work is concerned with developing a resin selection method to identify viable TLCP candidates and establish processing conditions for successful rotational molding. This was accomplished by individually investigating each of the phenomenological steps of rotational molding to determine the requirements for acceptable performance in, or successful completion of, each step. The fundamental steps were: the characteristics and behavior of the powder in solids flow, the coalescence behavior of isolated particles, and the coalescence behavior of the bulk powder. The conditions identified in each step were then evaluated in a single-axis, laboratory scale, rotational molding unit. Finally, the rotationally molded product was evaluated by measuring several physical and mechanical properties to establish the effectiveness of the selection method. In addition to the development and verification of the proposed TLCP selection method, several significant results that pertain to the storage of cryogenic fluids were identified as the result of this work. The first, and argueably the most significant, was that the selection method led to the successful extension of the rotational molding process to include TLCPs. Also, the established mechanical properties were found to be similar to rotationally molded flexible chain polymers. The biaxial rotationally molded container was capable of performing to the specified requirements for cryogenic storage: withstand pressures up to 34 psi at both cryogenic and room temperatures, retain nitrogen as a gas and as a cryogenic liquid, the mechanical preform retaining nitrogen, as both a gas and as a cryogenic liquid, and resist the development of micro-cracks during thermal cycling to cryogenic conditions.
Ph. D.
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Chen, Hongyan. "Simulations of Shearing Rheology of Thermotropic Liquid Crystalline Polymers." University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1210991980.

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Shiwaku, Toshio. "Ordered structures formed by thermotropic nematic liquid crystalline polymers." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/144861.

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Wilson, David James. "Diffraction measurements of crystalline morphology in thermotropic random copolyesters." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241169.

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Pickles, Adrian Philip. "The rheology, properties and morphology of thermotropic liquid crystalline polymers." Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317227.

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Ishida, Hiroyuki. "Studies on Structure and Dynamics of Thermotropic Liquid Crystalline Polymers." 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/149788.

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Jenkins, Shawn Eric. "Synthesis and spinning of a new thermotropic liquid crystallinepolymers : characterization of fiber morphology and mechanical properties." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/8557.

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Zhang, Heping. "Structure and properties of oriented thermotropic liquid crystalline polyesters and polyamides." Thesis, University of Leeds, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305812.

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Bai, Yiqun. "Structure and properties of linear and star-like thermotropic liquid crystalline polymeric fibers." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/9976.

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Done, Dinshong. "Studies on the rheology and morphology of thermotropic liquid crystalline polymers." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/77792.

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It is known that the physical properties of as-processed liquid crystalline polymers are highly dependent on the thermal and deformation histories of the materials experienced. The purpose of this study has been to examine the effect of thermal history on the rheology and morphological texture for several thermotropic liquid crystalline polymers. These include two copolyesters of para-hydroxybenzoic acid and polyethylene terephthalate and a copolymer of para-hydroxy benzoic acid and 6-hydroxy-2-naphthoic acid. For all three systems, it was found that the viscosities at temperatures below the normal flow temperatures were reduced as a result of preheating. Furthermore, these polymers were able to flow at temperatures as much - as 50°C below their normal flow temperatures if preheated and cooled rapidly. Also found was that it took a few minutes for the viscosities of the preheated samples to recover to a higher level at which the flow was ceased, during this period the materials were processable. These behaviors were attributed to the supercooling of the nematic state formed at preheating temperatures. This was supported by the lack of transition peaks in DSC traces obtained under the same cooling history as that in the Rheometric Mechanical Spectrometer. In the cold die extrusion experiment, a skin/core structure was observed for most extrudates. The thickness of the skin layer was directly related to the orientation and tensile properties of the extrudate. The thicker the skin layer was, the better the orientation and tensile properties were. The thickness of the skin layer was also found to increase with the extrusion speed. However, the orientation was only limited to the skin layer with the core region was relatively unoriented. For the lubricated squeezing flow experiments, the newly designed device worked satisfactory and predicted the relationship that the transient biaxial extensional viscosities are very close to six times the transient shear viscosities for polystyrene at small strains. Loss of lubrication occurred at fairly low strains, 0.3 to 0.4, was the limit of this method. For all three liquid crystalline polymers, the transient biaxial extensional viscosity was found to decrease with the increase in squeezing rate and no steady state was reached. Yield stresses were observed for liquid crystalline polymers under the squeezing jump strain deformation and the magnitude of these yield stresses were of the order of several hundreds Pa. The existence of yield stresses could be due to the presence of some structure in the sample which prevented the stress from relaxing to zero. The constant stress lubricated squeezing flow method has been proved to not be suitable for estimating the biaxial extensional viscosity of liquid crystalline polymers because the constant slope region for the creep curve was too short and it was difficult to determine the extension rate accurately. Under a heavy stress of 70368 Pa and proper cooling, it was possible to generate some fibrous structure in the squeezed sample.
Ph. D.
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Books on the topic "Thermotropic Liquid Crystalline Polymers"

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Donald, A. M. Liquid crystalline polymers. Cambridge [England]: Cambridge University Press, 1992.

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Thakur, Vijay Kumar, and Michael R. Kessler, eds. Liquid Crystalline Polymers. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-20270-9.

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Thakur, Vijay Kumar, and Michael R. Kessler, eds. Liquid Crystalline Polymers. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-22894-5.

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Weiss, R. A., and C. K. Ober, eds. Liquid-Crystalline Polymers. Washington, DC: American Chemical Society, 1990. http://dx.doi.org/10.1021/bk-1990-0435.

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National Research Council (U.S.). Committee on Liquid Crystalline Polymers. Liquid crystalline polymers: Report. Washington, D.C: National Academy Press, 1990.

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Cracknell, Steven J. Assessment of some novel thermotropic liquid crystalline phthalocyanines. Norwich: University of East Anglia, 1991.

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Shibaev, Valery P. Liquid Crystalline and Mesomorphic Polymers. New York, NY: Springer New York, 1994.

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Shibaev, Valery P., and Lui Lam, eds. Liquid Crystalline and Mesomorphic Polymers. New York, NY: Springer New York, 1994. http://dx.doi.org/10.1007/978-1-4613-8333-8.

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Chapoy, L. Lawrence, ed. Recent Advances in Liquid Crystalline Polymers. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4934-8.

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C, Carfagna, ed. Liquid crystalline polymers: Proceedings of the International Workshop on Liquid Crystalline Polymers, WLCP 93, Capri, Italy, June 1-4, 1993. Oxford, England: Pergamon, 1994.

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Book chapters on the topic "Thermotropic Liquid Crystalline Polymers"

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Platé, N. A., and V. P. Shibaev. "Thermotropic Liquid-Crystalline Polymers." In Comb-Shaped Polymers and Liquid Crystals, 197–415. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4613-1951-1_5.

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Rahman, Ahmed O., Rahul K. Gupta, and Sati N. Bhattacharya. "Recent Advances in the Rheology of Thermotropic Liquid Crystal Polymers." In Liquid Crystalline Polymers, 69–102. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-20270-9_4.

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Chiellini, Emo, and Giancarlo Galli. "Chiral Thermotropic Liquid Crystal Polymers." In Recent Advances in Liquid Crystalline Polymers, 15–56. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4934-8_2.

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Inoue, Toshihide. "Thermotropic Liquid Crystalline Polyarylates." In Progress in Pacific Polymer Science 2, 261–72. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-77636-6_24.

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Donald, A. M., and A. H. Windle. "Electron Microscopy of Thermotropic Copolyesters." In Recent Advances in Liquid Crystalline Polymers, 187–221. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4934-8_12.

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Denn, Morton M., and Jeffrey A. Reimer. "Rheology of Thermotropic Nematic Liquid Crystalline Polymers." In Nematics, 107–12. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3428-6_8.

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Chiellini, Emo, and Giancarlo Galli. "Chiral Thermotropic Liquid Crystalline Polymers: An Overview." In Recent Advances in Mechanistic and Synthetic Aspects of Polymerization, 425–50. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3989-9_34.

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Hanna, S., B. L. Hurrell, and A. H. Windle. "Crystallization of Thermotropic Main-Chain Liquid-Crystalline Copolyesters." In Crystallization of Polymers, 559–64. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1950-4_56.

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Noёl, Claudine. "Structure and Characterization of Thermotropic Liquid Crystalline Polymers." In Recent Advances in Liquid Crystalline Polymers, 135–64. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4934-8_9.

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Bhaskar, C., J. Kops, B. Marcher, and H. Spanggaard. "Thermotropic Liquid Crystal Aromatic Copolyesters Containing Cycloaliphatic Units." In Recent Advances in Liquid Crystalline Polymers, 79–87. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4934-8_4.

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Conference papers on the topic "Thermotropic Liquid Crystalline Polymers"

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Chen, Hongyan, Arkady I. Leonov, Albert Co, Gary L. Leal, Ralph H. Colby, and A. Jeffrey Giacomin. "Simulations of Shearing Rheology of Thermotropic Liquid Crystalline Polymers." In THE XV INTERNATIONAL CONGRESS ON RHEOLOGY: The Society of Rheology 80th Annual Meeting. AIP, 2008. http://dx.doi.org/10.1063/1.2964734.

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Goto, H., K. Akagi, R. Shirakawa, S. Y. Oh, and K. Araya. "Thermotropic liquid crystalline conjugated polymers, poly(cyclohexylphenoxyacetylenes) - synthesis and properties." In International Conference on Science and Technology of Synthetic Metals. IEEE, 1994. http://dx.doi.org/10.1109/stsm.1994.835262.

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Rohatgi, A., J. N. Baucom, W. R. Pogue, and J. P. Thomas. "Microstructure-Property Relation in a Liquid Crystalline Polymer-Carbon Nanofiber Composite." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-80045.

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Microstructure-property relationship is being examined in a polymer matrix composite system consisting of vapor grown carbon nanofibers (VGCF) mixed in a thermotropic liquid crystalline polymer (LCP) matrix. These nanocomposites show an inherent hierarchical structuring, which we hope to utilize in the development of multifunctional structure-conduction composites with improved performance. Among unfilled polymers, extruded LCPs show relatively high strength and high stiffness that have been attributed in the literature to the preferential molecular alignment along the extrusion direction and the hierarchical nature of LCPs. Further, as is typical for polymers, LCPs have poor thermal and electrical conductivity relative to metals. By contrast, carbon nanofibers are known to possess high strength, high stiffness and high conductivity in the axial direction. It is expected that the combination of the extrusion process and the similarity of the length-scales of LCP fibrils and carbon nanofibers will lead to improved axial alignment of both phases within the nanocomposite filaments. This simultaneous alignment of the LCP matrix and that of the carbon nanofibers is expected to lead to interesting mechanical and conductive behavior in the nanocomposite filaments through hierarchical interactions at the nanometer to micrometer scale levels. Carbon nanofibers, 60-150 nm in diameter, were mixed with Vectra A950 LCP and the mixture was extruded as 0.5–2 mm diameter filaments. Nanocomposite filaments with 1%, 2%, 5% and 10 wt.% VGCF were characterized via tensile testing and fractography. The tensile modulus, failure strength and strain-to-failure were found to be sensitive to filament diameter, carbon nanofiber content and extrusion process. There was a noticeable increase in mechanical performance with decreasing filament diameter irrespective of carbon nanofiber content. Fracture surfaces showed hierarchical features from nanometer to micrometer scale and processing defects in the form of voids. The results of this research will be used to fabricate composite components that exploit structural hierarchy from nano-to macro-scale.
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Rohatgi, A., J. P. Thomas, W. R. Pogue, and J. N. Baucom. "Fabrication and Characterization of a Carbon Nanofiber Reinforced Liquid Crystalline Polymer." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-15098.

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Our group at the Naval Research Laboratory is studying hierarchical arrangements of materials at multiple length scales and how such arrangements can be used to yield novel properties. We are investigating nanocomposites comprising a thermotropic liquid crystalline polymer (LCP) matrix reinforced with carbon nanofibers for potential structure + conduction multifunctional applications. The LCP matrix is known for its inherent hierarchical microstructure, and its fracture surface is typically characterized by fibrils ranging in size from nanometer to micrometer. The carbon nanofibers being compounded with the LCP matrix are vapor-grown carbon nanofibers (VGCF) and pre-processing techniques are being developed to eventually replace VGCF with single-wall carbon nanotubes (SWNT). Composites with VGCF content of 0, 1, 2, 5 and 10 wt.% were extruded using a twin-screw extruder to yield monofilaments in the range of 0.5 to 2 mm in diameter. The mechanical properties of extruded filaments were determined via quasi-static tensile tests and fracture surfaces examined under a scanning electron microscope. Porosity and hierarchical fibrillar structures were commonly observed in the fracture surfaces of tensile tested LCP and LCP-VGCF filaments. The LCP-VGCF filaments showed a maximum increase in strength and modulus of 20% and 35%, respectively, at 1-2 wt.% VGCF content. The dependence of mechanical properties on VGCF content was attributed to the interplay between the extrusion process parameters, VGCF dispersion and molecular alignment of LCP. In another set of experiments, LCP was thermo-mechanically pre-processed using a laboratory scale double-roll mixer and extruded using a Maxwell mixing extruder to yield monofilaments in the range of 0.2 to 0.7 mm. At 0.2 mm diameter, filaments of un-pre-processed and pre-processed neat LCP showed almost identical mechanical properties. At 0.7 mm diameter, however, pre-processed LCP filaments showed 10% and 30% degradation in strength and modulus, respectively, relative to un-pre-processed LCP. The lowered mechanical properties of pre-processed LCP were attributed to its chemical degradation during thermo-mechanical processing. Over the diameter range from 0.2 to 2 mm and irrespective of prior processing or extrusion method, the modulus and strength of neat LCP filaments increased with decreasing diameter. The strength and modulus dependence on filament diameter could be explained by the "skin-core" effect typically seen in liquid crystalline polymers. Future work will involve optimizing processing parameters for simultaneous enhancements in mechanical properties and electrical/thermal conductivity in LCP-VGCF/LCP-SWNT filaments.
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Ansari, Mubashir Q., and Donald G. Baird. "Generation of high performance polyphenylene sulfide-thermotropic liquid crystalline polymer composite filaments for use in fused filament fabrication." In PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5121693.

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RUSEK, JOHN. "Thermotropic liquid crystal polymers." In 27th Joint Propulsion Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1991. http://dx.doi.org/10.2514/6.1991-3375.

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SHELLEY, J. "Propulsion applications for thermotropic liquid crystal polymers." In 27th Joint Propulsion Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1991. http://dx.doi.org/10.2514/6.1991-3376.

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Saigal, Anil, Dan Ward, and Michael A. Zimmerman. "Impact Behavior of Liquid Crystalline Polymers." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-89096.

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Liquid crystalline polymers have the advantage of achieving desirable mechanical properties at a competitive cost. They are composed of molecular chains that are highly oriented and tightly packed at temperatures above and below its melting point. This high degree of orientation has the following advantages: ease of processing, high mechanical strength at extreme temperatures, and resistance to mostly all chemicals, weathering, radiation, and burning. On the other hand, this high degree of orientation causes liquid crystalline polymers to have low impact strength as well as an uneven amount of shrinkage prior to molding. The objective of this study is to determine the effects of injection-molding parameters on the impact behavior of liquid crystalline polymers, in an attempt to improve and understand the processing of the material. The conditions to be tested are as follows: fill speed, initial mold temperature, and packing pressure. The impact tester used for this research was an Instron Dynatup tester. Based on the data, it is apparent that fill speed is the greatest determining factor for optimizing the impact energy of the injection-molded liquid crystalline polymers followed by high packing pressure. In addition, even though the nature of the impact energy curves for LCPs and materials such as Delrin are similar, the impact load curves as a function of time are significantly different. This can be attributed to the layered structure of LCP samples.
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Ramos, Juan I. "FILM DRAWING OF LIQUID SEMI-CRYSTALLINE POLYMERS." In First Thermal and Fluids Engineering Summer Conference. Connecticut: Begellhouse, 2016. http://dx.doi.org/10.1615/tfesc1.fnd.012994.

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Fukuda, Jun-ichi. "Phase separation kinetics of liquid crystalline polymers." In The 8th tohwa university international symposium on slow dynamics in complex systems. AIP, 1999. http://dx.doi.org/10.1063/1.58501.

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Reports on the topic "Thermotropic Liquid Crystalline Polymers"

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Naslund, Robert A., and Phillip L. Jones. Characterization of Thermotropic Liquid Crystalline Polymer Blends by Positron Annihilation Lifetime Spectroscopy. Fort Belvoir, VA: Defense Technical Information Center, July 1992. http://dx.doi.org/10.21236/ada253616.

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Rusek, J. J., and M. Macler. Propellant Containment Via Thermotropic Liquid Crystal Polymers. Fort Belvoir, VA: Defense Technical Information Center, March 1998. http://dx.doi.org/10.21236/ada341792.

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Datta, A., J. P. De Souza, A. P. Sukhadia, and D. G. Baird. Processing Studies of Blends of Polypropylene with Liquid Crystalline Polymers. Fort Belvoir, VA: Defense Technical Information Center, January 1991. http://dx.doi.org/10.21236/ada232961.

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Komiya, Zen, Coleen Pugh, and Richard R. Schrock. Synthesis of Side Chain Liquid Crystal Polymers by Living Ring Opening Metathesis Polymerization. 1. Influence of Molecular Weight, Polydispersity, and Flexible Spacer Length (n=2-8) on the Thermotropic behavior of the Resulting Polymers. Fort Belvoir, VA: Defense Technical Information Center, March 1992. http://dx.doi.org/10.21236/ada248699.

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Perce, Virgil, Myongsoo Lee, and Dimitris Tomazos. Molecular Engineering of Liquid Crystalline Polymers by Living Cationic Polymerization. 21. Synthesis and Characterization of Poly(3-((4-Cyano-4'- Biphenyl)oxy)propyl Vinyl Ether) Macromonomers. Fort Belvoir, VA: Defense Technical Information Center, March 1992. http://dx.doi.org/10.21236/ada248305.

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Percec, Virgil, Myongsoo Lee, and C. Ackerman. Molecular Engineering of Liquid Crystalline Polymers by Living Polymerization. 9. Living Cationic Polymerization of 5-((4-Cyano-4'-Biphenyl) oxy)pentyl Vinyl Ethers and 7-((4-Cyano-4'-Biphenyl)oxy)heptyl Vinyl Ether, and the Mesomorphic Behavior of the Resulting Polymers. Fort Belvoir, VA: Defense Technical Information Center, October 1990. http://dx.doi.org/10.21236/ada229769.

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Originating super-strong liquid crystalline polymers (SSLCPs). Final report. Office of Scientific and Technical Information (OSTI), December 1994. http://dx.doi.org/10.2172/439010.

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