Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of Aromatic Ring Content on the Properties of Liquid Crystalline Copolyesters

방향족 고리 함량이 공중합 액정 폴리에스터의 성질에 미치는 영향

  • Park, Jong-Ryul (Division of Advanced Materials Science and Engineering, Kongju National University) ;
  • Bang, Moon-Soo (Division of Advanced Materials Science and Engineering, Kongju National University)
  • 박종률 (공주대학교 신소재공학부) ;
  • 방문수 (공주대학교 신소재공학부)
  • Received : 2013.09.16
  • Accepted : 2014.01.09
  • Published : 2014.01.31
Download PDF
⟨ Previous Next ⟩

Abstract

The liquid crystalline copolymers were synthesized through direct polycondensation using 4-[4-(4-hydroxyphenoxy)butoxy]benzoic acid (HBBA) and p-hydroxy benzoic acid (HBA) as monomers. The structure and properties for synthesized copolymers were investigated by $^1H$-NMR, FT-IR, differential scanning calorimetry (DSC), thermogravimetry analysis (TGA) and polarizing optical microscope (POM). As result of investigations, inherent viscosities (${\eta}_{inh}$) of polymers were measured as 0.77~1.60 dL/g in phenol/p-chlorophenol/1,1,2,2-tetrachloroethane (25/40/35=w/w/w). Except for P-80, the ranges of the transition and mesophase temperature of copolymers were increased with increasing the amount of HBA. These properties of polymers were presumably due to increasing of the irregularity and rigidity of polymer chains.

단위체로서 4-[4-(4-hydroxyphenoxy)butoxy]benzoic acid (HBBA)와 p-hydroxy benzoic acid (HBA)를 사용하여 직접 중축합방법에 의해 액정 공중합체를 합성하였다. 합성된 중합체의 구조와 성질은 $^1H$-NMR, FT-IR, DSC, TGA, POM에 의하여 조사되었다. 연구결과에 의하면, 페놀/p-클로로페놀/1,1,2,2-테트라클로로에탄 (25/40/35=w/w/w) 내에서 측정된 중합체의 고유점성도 (${\eta}_{inh}$)는 0.77~1.60 dL/g로 측정되었으며, 중합체 P-80을 제외하고, 공중합체들의 전이온도와 액정상의 범위는 HBA의 양이 증가함에 따라 증가하였다. 중합체의 이러한 특성은 중합체 사슬의 불규칙성과 강직성이 증가하였기 때문으로 생각된다.

Keywords

References

  1. A. Ciferri and B. Balenti, "Solution spinning of Rigid and Semi-rigid Polymers", in Ultra-High Modulus Polymers, Ed. A. Cifferi and I.M. Ward, Applied Science Publisher, London, 1979.
  2. W. J. Jackson Jr., and H. F. Kuhfuss, "liquid crystal polymers. I. Preparation and properties of p-hydroxybenzoic acid copolyesters", J. Polym. Sci., Polym. Chem., Vol. 34, pp. 3031-3046, 1975. DOI: http://dx.doi.org/10.1002/pola.1996.863
  3. F. E. McFarene, V. A. Nicely and T. G. Davis, "Liquid Crystalline Polymers. II. Preparation and Properties of Polyesters Exhibiting Liquid Crystalline Melts", in Contemporary Topics in Polymer Science, Ed. E. M. Pearce and J. R. Schaefgen, Vol. 2, Plenum Press, New York, 1977. DOI: http://dx.doi.org/10.1007/978-1-4615-6737-0_5
  4. T. S. Shung, ""The Recent Developments of Thermotropic Liquid Crystalline Polymers"", J. Polym. Eng. & Sci., Vol. 26, pp. 901-919, 1986. DOI: http://dx.doi.org/10.1002/pen.760261302
  5. Y. W. Kwon, D. H. Choi, and J. I. Jin, "Liquid Crystalline Aromatic Polyesters" Polymer(Korea), Vol. 29, pp. 523-535, 2005.
  6. D. Y. Kim, "Main Chain Liquid Crystalline Polymers", Polymer Science and Technology, Vol. 2, pp. 415-423, 1991.
  7. A. Kaito, M. Kyotani, and K. Nakayama, "Orientation profiles in the strand of thermotropic liquid-crystalline polymer studied by polarized Fourier-transform infrared microspectroscopy" Macromolecules, Vol. 24, pp. 3244-3249 1991. DOI: http://dx.doi.org/10.1021/ma00011a032
  8. V. Frosini, G. Levita, J. Landis, and A. E. Woodward. "Broad-line NMR and dynamic mechanical behavior of some aromatic polyesters", J. Polym. Sci., Polym. Phys. Ed., Vol. 15, pp. 239-245, 1977. DOI: http://dx.doi.org/10.1002/pol.1977.180150204
  9. R. Cai and E. T. Samulski, "liquid crystals polyesters containing isophthalic acid", Macromolecules, Vol. 27, pp. 135-140, 1994. DOI: http://dx.doi.org/10.1021/ma00079a020
  10. M. S. Bang, D. S. Yoon, and J. K. Choi, "Synthesis and Properties of Semi-Flexible Aromatic Polyesters Containing Pentamethylene Group in Main Chain" Elastomers and Composites, Vol. 44, 436-441, 2009.
  11. A. Blumstein. "Liquid Crystalline Order in Polymers'", Academic, New York, 1978.
  12. J. l Jin. S. Antoun, C. Ober and R. W. Lenz, "Thermotropic Liquid Crystalline Polyesters with Rigid or Flexible Spacer Groups" Brit. Polym. J., Vol. 12, pp. 132-146, 1980. DOI: http://dx.doi.org/10.1002/pi.4980120403
  13. L. Goodman, J. E. McIntyre, and W. J. Stimpson, Brit. Patent 989,553.
  14. B. W. Jo, K. Y. Sung, J. K. Choi, J. H. Chang and J. I. Jin, "Thermotropic Copolyesters Derived from p-hydroxybenzoic acid, naphthalenediol isomers and ${\alpha}$, ${\omega}$-bis(4-carboxy phenoxy)alkanes", Polymer (Korea), Vol. 13, pp. 675-682, 1989.
  15. M. S. Bang, J. H. Chang, and B. W. Jo, "On the composites of engineering Plastics with Liquid crystalline polyesters(I)" Polymer (Korea), Vol. 13, pp. 675-682, 1989.
  16. F. Higasi, T. Mashimo, and I. Takahashi, "Preparation of aromatic polyesters by direct polycondensation with thionyl chloride in pyridine" J. Polym. Sci. Polym. Chem. Ed., Vol. 24, pp. 97-102, 1986. DOI: http://dx.doi.org/10.1002/pol.1986.170240108