Effect of the Polymerization Methods on the Microstructure and Thermal/mechanical Properties of PU/organoclay Nanocomposites

중합방법의 차이가 PU/organoclay 나노복합체의 미세 구조 및 열적/기계적 특성에 미치는 영향

  • Shin, Na-Ri (Department of Textile Engineering, Inha University) ;
  • Kwon, Byung-Chol (Department of Textile Engineering, Inha University) ;
  • Park, Ki-Ho (Department of Textile Engineering, Inha University) ;
  • Lee, Han-Sup (Department of Textile Engineering, Inha University)
  • 신나리 (인하대학교 섬유공학과) ;
  • 권병철 (인하대학교 섬유공학과) ;
  • 박기호 (인하대학교 섬유공학과) ;
  • 이한섭 (인하대학교 섬유공학과)
  • Published : 2007.02.28

Abstract

Two different polymerization methods were used to synthesize the PU/organoclay nanocomposite by either 'one step addition' or 'two step addition' method. In two step addition method, the modified clay was reacted with isocyanate-terminated prepolymer to anchor the polymer chains to the silicate layers before the chain extension reaction occurred. On the other hand, the modified clay and chain extender were added simultaneously in the one step addition method. The effect of polymerization method on the exfoliated/intercalated structure of silicate layers as well as on the microphase separated structure of PU matrix has been studied with FTIR, SAXS and TEM methods. The PU/organoclay nanocomposite prepared with one step addition reaction showed better exfoliated structure which is effectively retarding the micro-phase separation process of PU. However, compared with two step addition one, one step addition method was more effective to enhance the initial modulus and tensile strength of the nanocomposites. The role of modified clay for the segmental orientation process was also studied by infrared dichroism method. The orientation process was hindered by the silicate layers and its effect was more pronounced in the nanocomposite by one step addition method.

Keywords

References

  1. C. Hepburn, 'Polyurethane Elastomers', 2nd Ed., Elsevier Applied Science, London and New York, 1992, pp.A-28
  2. M. F. Mark, N. M. Bikales, C. G. Overberger, and G. Menges, 'Encyclopedia of Polymer Science and Engineering', 2nd Ed., John Wiley & Sons, New York, 1988
  3. N. S. Schneider, C.S. Paik, R. W. Matton, and J. L. Lilinger, 'Thermal Transition Behavior of Polyurethanes Based on Toluene Diisocyanate', Macromolecules, 1975, 8, 62-67 https://doi.org/10.1021/ma60043a014
  4. F. W. Seymour and S. L. Cooper, 'Thermal Analysis of Polyurethane Block Polymers', Macromolecules, 1973, 6(1), 48-53 https://doi.org/10.1021/ma60031a008
  5. T. D. Fornes, P. J. Yoon, D. L. Hunter, H. Keskkula, and D. R. Paul, 'Effect of Organoclay Structure on Nylon 6 Nanocomposite Morphology and Properties', Polymer, 2002, 43, 5915-5920 https://doi.org/10.1016/S0032-3861(02)00400-7
  6. A. C. Balazs, C. Singh, and E. Zhulina, 'Modeling the Interactions between Polymers and Clay Surfaces through Self-Consistent Field Theory', Macromolecules, 1998, 31, 8370-8378 https://doi.org/10.1021/ma980727w
  7. R. Xu, E. Manias, A. J. Snyder, and J. Runt, 'New Biomedical Poly(urethane urea)-Layered Silicate Nanocomposites', Macromolecules, 2001, 34(2), 337-339 https://doi.org/10.1021/ma0013657
  8. S. S. Ray and M. Okamoto, 'Polymer/layered Silicate Nanocomposites: A Review from Preparation to Processing', Progress Polym Sci, 2003, 28(11), 1539-1641 https://doi.org/10.1016/j.progpolymsci.2003.08.002
  9. P. B. Messersmith and E. P. Giannelis, 'Synthesis and Barrier Properties of Poly(caprolactone)-layered Silicate Nanocomposites', J Polym Sci, Part A: Polym Chem, 1995, 33(7), 1047-1057 https://doi.org/10.1002/pola.1995.080330707
  10. M. Y. Choi, S. Anandhan, J. H. Youk, D. H. Baik, S. W. Seo, and H. S. Lee, 'Synthesis and Characterization of in situ Polymerized Segmented Thermoplastic Elastomeric Polyurethane/layered Silicate Clay Nanocomposites', J Appl Polym Sci, 2006, 102(3), 3048-3055 https://doi.org/10.1002/app.24734
  11. J. H. Hong, E. H. Jeong, H. S. Lee, D. H. Baik, S. W. Seo, and J. H. Youk, 'Electrospinning of Polyurethane/Organically Modified Montmorillonite Nanocomposites', J Polym Sci: Polymer Physics, 2005,43,3171-3177 https://doi.org/10.1002/polb.20610
  12. Y. I. Tien and K. H. Wei, 'High-Tensile Property Layered Silicates/Polyurethane Nanocomposites by Using Reactive Silicates as Pseudo-Chain Extenders', Macromolecules, 2001, 34, 9045-9052 https://doi.org/10.1021/ma010551p
  13. B. S. Seo, H. S. Lee, and M. J. Jin, 'Synthesis and Structural Analysis of Thermal and Photo-Crosslinkable Polyurethane with High Thermal Stability. 1. Mechanical Property and Orientational Behavior', J Korean Fiber Soc, 1997, 34(3), 148-157
  14. H. S. Lee, S. R. Yoo, and S. W. Seo, 'Domain and Segmental Deformation Behavior of Thermoplastic Elastomers Using Synchrotron SAXS and FTIR Methods', J Polym Sci: Polymer Physics, 1999, 37, 3233-3245 https://doi.org/10.1002/(SICI)1099-0488(19991115)37:22<3233::AID-POLB8>3.0.CO;2-J
  15. H. S. Lee, J. H. Ko, K. S. Song, and K. H. Choi, 'Segmental and Chain Orientational Behavior of Spandex Fibers', J Polym Sci: Polymer Physics, 1997,35, 1821-1832 https://doi.org/10.1002/(SICI)1099-0488(199708)35:11<1821::AID-POLB13>3.0.CO;2-A
  16. C. H. M. Facques, 'Polymer Alloy', Plenum Press, New York, 1977, p.287
  17. H. S. Lee, 'Determination of Molecular Orientation of Fibrous Polymer by Infrared Spectroscopy', J Korean Fiber Soc, 1991, 28(8), 539-545