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Synthesis and Characterization of New Thermotropic Liquid Crystalline Polyurethanes with Naphthalene Moiety  

Lee, Jong-Baek (Department of Chemical Engineering, Dongeui University)
Lee, Kwang-Hyun (Department of Chemical Engineering, Dongeui University)
Publication Information
Elastomers and Composites / v.40, no.1, 2005 , pp. 37-44 More about this Journal
Abstract
Novel polyurethanes containing no mesogenic unit were synthesized by the polyaddition reaction of para-type diisocyanates such as 2,5-tolylene diisocyanate (2,5-TDI) or 1,4-phenylene diisocyanate (1,4-PDI) with 2,6-bis(${\omega}$-hydroxyalkoxy)naphthalene (BHNm; m= 5, 6, 8, 11). Intrinsic viscosities of the polymers were in the range of 0.28-0.43 dL/g. The thermal properties of these polymers were studied by differential scanning calorimetry and polarizing microscopy. Polyurethanes prepared from BHNm and 2,5-TDI haying methyl substituent on the phenylene unit exhibited monotropic liquid crystallinity. However, in the series of polyurethanes prepared from 1,4-PDI and BHNm, no explicit mesomorphic behavior was observed by differential scanning calorimetry and polarizing microscopy.
Keywords
polyurethane; liquid crystallinity; BHN; para-type diisocyanate;
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  • Reference
1 T. Uryu, and T. Kato, 'Solid-State Cross polarization/ Magic Angle Spinning $^{13}C$ NMR Study of Thermotropic Aromatic Polyester Containing a Flexible Spacer in The Main Chin', Macromolecules, 21, 378 (1988)
2 K. Iimura, N. Koide, H. Tanabe, and M. Takeda, 'Syntheses of Thermotropic Liquid Crystalline Polymers', Makrmol. Chem., 182, 2569 (1981)
3 M. Tanaka, and T. Nakaya, 'Liquid crystalline Polyurethanes', Makromol. Chem., 187, 2345 (1986)
4 P. J. Stenhouse, E. M. Valles, S. W. Kantor, and W. J. MacKnight, 'Thermal and Rheological Properties of a Liquid-Crystalline polyurethane', Macromolecules, 22, 1467 (1989)   DOI   ScienceOn
5 J. B. Lee, T. Kato, S. Ujiie, K. Iimura, and T. Uryu, 'Thermotropic Polyurethanes Prepared from 2,5-Tolylene Diisocyanates and 1,4-Bis($\omega$-hydroxyalkoxy)benzenes Containing No Mesogenic Unit', Macromolecules, 28, 2165 (1995)
6 J. B. Lee, 'The Effect of Substituents on the Liquid Crystalline Behavior of Polyurethanes', J. Korean Ind Eng. Chem., 12, 649 (2001)
7 J. I. Jin, S. Antoun, C. Ober, and R. W. Lenz, 'Thermotropic Liquid Crystalline Polyesters with Rigid or Flexible Spacer Groups', Polym. J., 12, 132 (1980)
8 P. J. Collings, M. Hird, 'Introduction to Liquid Crystals', Taylor & Francis Ltd, London, 1997
9 H. S. Lee, W. H. Jung, W. N. Kim, and J. C. Hyun, 'Properties of Blends of Polycarbonate and Thermotropic Liquid Crystalline Polymer', Polymer (Korea), 29, 813 (1996)
10 H. M. Jeong, J. B. Lee, S. Y. Lee, and B. K. Kim,'Shape Memory Polyurethane Containing Mesogenic Moiety', J. of Materials Sci., 35, 279 (2000)
11 J. B. Lee, 'Thermal Properties of Liquid-Crystalline Polyurethanes Containing Biphenylene Mesogenic Unit', J. Ind Eng. Chem., 6, 338 (2000)
12 D. J. Lee, J. B. Lee, N. Koide, E. Akiyama, and T. Uryu, 'Liquid Crystallinity of Thermotropic ParaType Home- and Copolyurethanes containing Biphenylene Mesogen and Their Blends', Macromolecules, 31, 975 (1998)
13 C. H. Lin, J. F. Kuo, and C. Y. Chen, 'Synthesis and mesomorphism of thermotropic liquid crystalline polyurethanes based on meta-diisocyanates with 4,4 '-bis($\omega$-hydroxyalkoxy)biphenyls', European polymer journal, 36, 1183 (2000)
14 J. Salamone, 'Polymetric Materials', ed. by C. D. Eisenbach, p.6957, Boca Raton, New York, 1996
15 P. Penczek, K. C. Frisch, B. Szczepaniak, and E. Rudnik, 'Synthesis and Properties of Liquid Crystalline Polyurethanes', J. Polym. Sci., Part A: Polym. Chem., 31, 1211 (1993)
16 W. Mormann and M. Brahm, 'Polymers from Multfunctional Isocyanates', Macromolecules, 24, 1096 (1991)
17 P. J. Collings, 'Liquid crystals', ed. by P. J. Collings, p.3, Princeton University Press, 1990
18 J. B. Lee, T. Kato, T. Yoshida, and T. Uryu, 'Synthesis and Liquid Crystalline Properties of Thermotropic Polyurethanes Prepared from 1,4-Diisocyanates and 4,4' -Bis($\omega$-hydroxyalkoxy)biphenyls', Macromolecules, 26, 4989 (1993)
19 J. B. Lee, 'Synthesis and Properties of Biphenylene Mesogen Containing 4,4' -bis($\omega$-hydroxyalkoxy)biphenyls', J. Korean Ind Eng. Chem., 13, 654 (2002)