The Non Newtonian Flow Mechanism and Rheological Properties of Polyurethane Melts

용융 폴리우레탄의 비 뉴톤 유동 메카니즘과 유변학적인 성질

  • Published : 2009.12.31

Abstract

The non-Newtonian flow curves of polyurethane melts were obtained by using a Physica cone-plate rheometer at various temperatures. The rheological parameters were obtained by applying non-Newtonian flow equation to the flow curves for polyurethane samples. When the polyurethane samples are under increasing-decreasing shear rate modes, the hysteresis loop and thixotropic behavior were shown. Polyurethane melts behave as strong gels when they are subjected to shear flow, but when the applied stress surpasses the yield stress, they exhibit non-linear viscoelasticity. Upon decreasing shear rate, its shear stress remains smaller than the values measured in the increasing shear rate mode, because of broken of its structure.

References

  1. X. D. Wang, X. Luo, and X. F. Wang, 'Study on blends of thermoplastic polyurethane and aliphatic polyester: morphology, rheology, and properties as moisture vapor permeable films', Polym. Test., 24, 18 (2005) https://doi.org/10.1016/j.polymertesting.2004.08.003
  2. K. F. Grythe, F. K. Hansen, and H. Walderhaug, 'NMR self-diffusion and viscosity of polyurethane formulation for rocket propellants', J. Phys. Chem. B, 108, 12404 (2004) https://doi.org/10.1021/jp049713k
  3. K. Palanivelu, P. Sivaraman, and M.D. Reddy, 'Studies on thermoplastic polyurethane toughened poly(butylene terephthalate) blends', Polym. Test., 21, 345 (2002) https://doi.org/10.1016/S0142-9418(01)00095-2
  4. Q. W. Lu, M.E. Hernandez-Hernandez, and C.W. Macosko, 'Explaining the abnormally high flow activation energy of thermoplastic polyurethanes', Polymer, 44, 3309 (2003) https://doi.org/10.1016/S0032-3861(03)00223-4
  5. N. J. Kim, 'Determination of Self Diffusion Distributions of Molten Polyurethanes by Relaxation Spectra', Journal of the Korean Chemical Society, 50, 196 (2006) https://doi.org/10.5012/jkcs.2006.50.3.196
  6. J. H. Bang, N. J. Kim S. W. Choi, E. R. Kim, and S. J. Hahn, 'The equilibrium between dilatant and thixotropic flow units', Bull. Korean Chem. Soc., 17, 262 (1996) https://doi.org/10.1007/BF02699037
  7. I. Wagstaff and C.E. Chaffey, 'Shear thinning and thickening rheology : I. Concentrated acrylic dispersions', J. Colloid and Interface Sci., 59, 53 (1977) https://doi.org/10.1016/0021-9797(77)90338-1
  8. C. H. Lee, V. Moturi, and Y. Lee, 'Thixotropic property in pharmaceutical formulations', Journal of Controlled Release, 136, 88 (2009) https://doi.org/10.1016/j.jconrel.2009.02.013
  9. J. Lin, Z. Wen, Y. Liu, X. Xu, S. Song, and N. Li, 'Rheological behavior of aqueous polymer-plasticized $\gamma$-LiAlO_2 pastes for plastic forming', Ceramics International, 35, 2289 (2009) https://doi.org/10.1016/j.ceramint.2009.01.001
  10. R. Durairaj, S. Ramesh, S. Mallik, A. Seman, and N. Ekere, 'Rheological characterisation and printing performance of Sn/Ag/Cu solder pastes', Materials & Design, 30, 3812 (2009) https://doi.org/10.1016/j.matdes.2009.01.028
  11. B. S. Ghotra, T. Vasanthan, and F. Temelli, 'Rheological properties of aqueous blends of high purity barley $\beta$-glucan with high purity commercial food gums', Food Chemistry, 117, 417 (2009) https://doi.org/10.1016/j.foodchem.2009.04.027
  12. N .J. Kim, 'Thixotropic properties of polyacrylamide hydrogels with various synthetic conditions', Journal of the Korean Chemical Society, 50, 447 (2006) https://doi.org/10.5012/jkcs.2006.50.6.447
  13. Q. W. Lu, M.E. Hernandez-Hernandez, and C.W. Macosko, 'Explaining the abnormally high flow activation energy of thermoplastic polyurethanes', Polymer, 44, 3309 (2003) https://doi.org/10.1016/S0032-3861(03)00223-4