Browse > Article

The Non Newtonian Flow Mechanism and Rheological Properties of Polyurethane Melts  

Kim, Nam-Jeong (Department of Chemistry, Sahmyook University)
Publication Information
Elastomers and Composites / v.44, no.4, 2009 , pp. 423-428 More about this Journal
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.
Keywords
rheological properties; non-Newtonian flow phenomena; hysteresis loop; thixotropic behavior; non-linear viscoelasticity;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
연도 인용수 순위
1 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)   DOI   ScienceOn
2 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)   DOI   ScienceOn
3 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)   DOI   ScienceOn
4 N .J. Kim, 'Thixotropic properties of polyacrylamide hydrogels with various synthetic conditions', Journal of the Korean Chemical Society, 50, 447 (2006)   DOI
5 I. Wagstaff and C.E. Chaffey, 'Shear thinning and thickening rheology : I. Concentrated acrylic dispersions', J. Colloid and Interface Sci., 59, 53 (1977)   DOI   ScienceOn
6 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)   DOI   ScienceOn
7 K. Palanivelu, P. Sivaraman, and M.D. Reddy, 'Studies on thermoplastic polyurethane toughened poly(butylene terephthalate) blends', Polym. Test., 21, 345 (2002)   DOI   ScienceOn
8 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)   DOI   ScienceOn
9 N. J. Kim, 'Determination of Self Diffusion Distributions of Molten Polyurethanes by Relaxation Spectra', Journal of the Korean Chemical Society, 50, 196 (2006)   DOI
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)   DOI   ScienceOn
11 C. H. Lee, V. Moturi, and Y. Lee, 'Thixotropic property in pharmaceutical formulations', Journal of Controlled Release, 136, 88 (2009)   DOI   ScienceOn
12 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)   DOI   ScienceOn
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)   DOI   ScienceOn