Abstract
Stress-optical measurements are used to quantitatively determine the third-normal stress difference (N 3 = N 1 + N 2) in three entangled polymer melts during small amplitude (<15%) oscillatory shear over a wide dynamic range. The results are presented in terms of the three material functions that describe N 3 in oscillatory shear: the real and imaginary parts of its complex amplitude ψ *3 = ψ ′3 - iψ ″3 , and its displacement ψ d3 . The results confirm that these functions are related to the dynamic modulus by ω2ψ *3 (ω)=(1-β)[G *(ω))−\(\frac{1}{2}\) G *(2ω)] and ω2ψ d3 (ω)=(1- β)G′(ω) as predicted by many constitutive equations, where β = −N 2/N 1. The value of (1-β) is found to be 0.69±0.07 for poly(ethylene-propylene) and 0.76±0.07 for polyisoprene. This corresponds to −N 2/N 1 = 0.31 and 0.24±0.07, close to the prediction of the reptation model when the independent alignment approximation is used, i.e., −N 2/N 1 = 2/7 − 0.28.
Similar content being viewed by others
References
Alvarez GA, Lodge AS, Cantow H-J (1985) Measurement of the first and second normal stress differences: Correlation of four experiments on a polyisobutylene/decalin solution ‘D’. Rheol Acta 24:368
Bird RB, Armstrong RC, Hassager O (1987) Dynamics of polymeric liquids, v. 1: Fluid mechanics, ch. 388. Wiley, New York
Doi M, Edwards SF (1979) Dynamics of concentrated polymer systems IV: Rheological properties. J Chem Soc Faraday Trans II 75:38
Doi M, Edwards SF (1988) The theory of polymer dynamics, ch. 7. Clarendon Press, Oxford
Ferry JD (1980) Viscoelastic properties of polymers, 3rd ed. Wiley, New York
Fuller GG (1990) Optical rheometry. Ann Rev Fluid Mech 22:387
Gao HW, Ramachandran S, Christiansen EB (1981) Dependency of the steady-state and transient viscosity and first and second normal stress difference functions on molecular weight for linear mono and polydisperse polystyrene solutions. J Rheol 25:213
Gotro JT, Graessley WW (1984) Model hydrocarbon polymers: Rheological properties. Macromolecules 17:2767
Janeschitz-Kriegl H (1983) Polymer melt theology and flow birefringence. Springer, New York
Johnson SJ, Frattini PL, Fuller GG (1985) Simultaneous dichroism and birefringence measurements of dilute colloidal suspensions in transient shear flow. J Coll Int Sci 104:440
Kannan RM, Kornfield JA, Schwenk N, Boeffel C (1992) On: Rheology of side-group liquid-crystalline polymers: Effect of the isotropic-nematic transition and evidence of flow alignment (to be submitted to Macromolecules)
Kimura S, Osaki K, Kurata M (1981) Stress relaxation of polybutadiene at large deformation: Measurements of stress and birefringence in shear and elongation. J Polymer Sci: Polymer Phys Ed 19:151
Kornfield JA, Fuller GG, Pearson DS (1990) Stress-optical measurements of the third normal stress difference in polymer melts under oscillatory shear. Rheol Acta 29:105
Kuhn W, Grün F (1946) Statistical behavior of the single chain molecule and its relation to the statistical behavior of assemblies consisting of many chain molecules. J Polymer Sci 1:193
Kuo Y, Tanner RI (1974) On the use of open-channel flows to measure the second normal stress difference. Rheol Acta 13:443
Larson RG (1988) Constitutive equations for polymer melts and solutions. Butterworths, Boston
Lee C-S, Magda JJ, De Vries KL, Mays JW (1992) Measurements of the second normal stress difference for star polymers with highly entangled branches. Macromolecules 25:4744
Meissner J, Garbella RW, Hostettler J (1989) Measuring the second normal stress differences in polymer melt shear flow. J Rheol 33:843
Muller SJ, Larson RG, Shagfeh ESG (1989) A purely elastic transition in Taylor-Couette flow. Rheol Acta 28:499;
Larson RC, Shaqfeh ESG, Muller SJ (1990) A purely elastic instability in Taylor-Couette flow. J Fluid Mech 218:573
Osaki K, Kimura S, Kurata M (1981) Relaxation of shear and normal stresses in step-shear deformation of a polystyrene solution. Comparison with the predictions of the Doi-Edwards theory. J Polymer Sci: Polymer Phys Ed 19:517
Rosedale JH, Bates FS (1990) Rheology of ordered and disordered symmetric poly(ethylenepropylene)-poly (ethylethylene) diblock copolymers. Macromolecules 23:2329
Spriggs TW, Huppler JD, Bird RB (1966) An experimental appraisal of viscoelastic models. Trans Soc Rheo 10:191
Vinogradov GV, Isayev AI, Mustafaev DA, Podolsky YY (1978) Polarization-optical investigation of polymers in fluid and high-elastic states under oscillatory deformation. J Appl-Polymer Sci 22:665
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kannan, R.M., Kornfield, J.A. The third-normal stress difference in entangled melts: Quantitative stress-optical measurements in oscillatory shear. Rheola Acta 31, 535–544 (1992). https://doi.org/10.1007/BF00367008
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00367008