Rheologica Acta

, Volume 46, Issue 7, pp 1003–1012

Comparison of the elongational behavior of various polyolefins in uniaxial and equibiaxial flows

  • F. J. Stadler
  • A. Nishioka
  • J. Stange
  • K. Koyama
  • H. Münstedt
Original Contribution

Abstract

For processing operations with a pronounced elongational component, it was found that the uniformity of extruded items is improved by the presence of strain hardening usually measured in uniaxial elongation. Many processing operations such as foaming, film blowing, and blow molding are dominated by biaxial deformations, however, and therefore, the question arises how strain hardening in uniaxial and biaxial deformation compares. Besides a linear and long-chain branched PP, one classical LDPE, an HDPE pipe extrusion grade with a bimodal MMD, and a LCB-mPE were also characterized. For the measurements in uniaxial elongation the Münstedt tensile rheometer (MTR) and the ARES-EVF were used, while the lubricated flow method was applied for equibiaxial deformation. It was found that the strain hardening in uniaxial elongation is more pronounced. The dependence of strain hardening on strain rate is qualitatively the same in both modes. In the range of strain rates, the chosen long-chain branched LDPE and PP exhibit a strain hardening, which is approximately independent of the elongational rates applied, whereas for the HDPE it becomes smaller with increasing rate.

Keywords

Uniaxial elongation Equibiaxial elongation Strain hardening Polyolefins Long-chain branching 

References

  1. Auhl D, Stange J, Münstedt H, Krause B, Voigt D, Lederer A, Lappan U, Lunkwitz K (2004) Long-chain branched polypropylenes by electron beam irradiation and their rheological properties. Macromolecules 37(25):9465–9472CrossRefGoogle Scholar
  2. Auhl D, Kaschta J, Münstedt H, Kaspar H, Hintzer K (2006) Molecular characterization of semi-fluorinated copolymers with a controlled amount of long-chain branching. Macromolecules 39(6):2316–2324CrossRefGoogle Scholar
  3. Bach A, Rasmussen HK, Longin P-Y, Hassager O (2002) Growth of non-axisymmetric disturbances of the free surface in the filament stretching rheometer: experiments and simulation. J Non-Newton Fluid Mech 108(1–3):163–186CrossRefGoogle Scholar
  4. Bastian H (2001) Non-linear viscoelasticity of linear and long-chain-branched polymer melts in shear and extensional flows. University Berlin, PhD ThesisGoogle Scholar
  5. Beer F, Capaccio G, Rose LJ (1999) High molecular weight tail and long-chain branching in SRM 1476 polyethylene. J Appl Polym Sci 73(14):2807–2812CrossRefGoogle Scholar
  6. Chatraei S, Macosko CW, Winter HH (1981) Lubricated squeezing flow: a new biaxial extensional rheometer. J Rheol 25(4):433–443CrossRefGoogle Scholar
  7. Gabriel C, Münstedt H (2002) Influence of long-chain branches in polyethylenes on linear viscoelastic flow properties in shear. Rheol Acta 41(3):232–244CrossRefGoogle Scholar
  8. Gabriel C, Münstedt H (2003) Strain hardening of various polyolefins in uniaxial elongational flow. J Rheol 47(3):619–630CrossRefGoogle Scholar
  9. Gabriel C, Kokko E, Löfgren B, Seppälä J, Münstedt H (2002) Analytical and rheological characterization of long-chain branched metallocene-catalyzed ethylene homopolymers. Polymer 43(24):6383–6390CrossRefGoogle Scholar
  10. Hachmann P, Meissner J (2003) Rheometer for equibiaxial and planar elongations of polymer melts. J Rheol 47(4):989–1010CrossRefGoogle Scholar
  11. Hattori T, Takigawa T, Masuda T (1992) Uniaxial and biaxial elongational flow of low-density polyethylene/polystyrene blends. Nihon Reoroji Gakkaishi 20(3):141–145Google Scholar
  12. Hsu TC, Harrison IR (1994) Experimental factors in measurement of elongational viscosity using lubricated squeezing. Annu Technol Confer Soc Plast Eng 52nd 2:1816–1818Google Scholar
  13. Kompani M, Venerus DC (2000) Equibiaxial extensional flow of polymer melts via lubricated squeezing flow. I. Experimental analysis. Rheol Acta 39(5):444–451CrossRefGoogle Scholar
  14. Krause B, Voigt D, Lederer A, Auhl D, Münstedt H (2004) Determination of low amounts of long-chain branches in polypropylene using a combination of chromatographic and rheological methods. J Chromatogr 1056(1–2):217–222CrossRefGoogle Scholar
  15. Kurzbeck S, Oster F, Münstedt H, Nguyen TQ, Gensler R (1999) Rheological properties of two different polypropylenes with different molecular structures. J Rheol 43(2):359–374CrossRefGoogle Scholar
  16. Laun HM, Münstedt H (1978) Elongational behaviour of a low density polyethylene melt I. Strain rate and stress dependence of viscosity and recoverable strain in the steady-state. Comparison with shear data. Influence of interfacial tension. Rheol Acta 17:415–425CrossRefGoogle Scholar
  17. Linster JJ, Meissner J (1986) Melt elongation and structure of linear polyethylene (HDPE). Polym Bull (Berlin, Germany) 16(2–3):187–194CrossRefGoogle Scholar
  18. Malmberg A, Gabriel C, Steffl T, Münstedt H, Löfgren B (2002) Long-chain branching in metallocene-catalyzed polyethylenes investigated by low oscillatory shear and uniaxial extensional rheometry. Macromolecules 35:1038–1048CrossRefGoogle Scholar
  19. Meissner J (1969) Rheometer for the study of mechanical properties of deformation of plastic melts under definite tensile stress. Rheol Acta 8(1):78–88CrossRefGoogle Scholar
  20. Meissner J, Raible T, Stephenson SE (1981) Rotary clamp in uniaxial and biaxial extensional rheometry of polymer melts. J Rheol 25(1):1–28CrossRefGoogle Scholar
  21. Minegishi A, Nishioka A, Takahashi T, Masubuchi Y, Takimoto J-I, Koyama K (2001) Unaxial elonational viscosity of PS/a small amount of UHMW-PS blends. J Rheol 40:329–338CrossRefGoogle Scholar
  22. Mitsoulis E, Schwetz M, Münstedt H (2003) Entry flow of LDPE melts in a planar contraction. Polymer 111:41–61Google Scholar
  23. Münstedt H (1979a) New universal extensional rheometer for polymer melts. Measurements on a polystyrene sample. J Rheol 23(4):421–436CrossRefGoogle Scholar
  24. Münstedt H (1979b) Elongational behavior of a low density polyethylene melt II. Transient behavior in constant stretching rate and tensile creep experiments. Comparison with shear data. Temperature dependence of the elongational properties. Rheol Acta 18:492–504CrossRefGoogle Scholar
  25. Münstedt H (1980) Dependence of the elongational behavior of polystyrene melts on molecular weight and molecular weight distribution. J Rheol 24(6):847–867CrossRefGoogle Scholar
  26. Münstedt H, Auhl D (2005) Rheological measuring techniques and their relevance for the molecular characterization of polymers. J Non-Newton Fluid Mech 128(1):62–69CrossRefGoogle Scholar
  27. Münstedt H, Kurzbeck S (1998) Comparison of creep and stressing experiments on polyolefin melts in elongation. Progress and Trends in Rheology V. Proceedings of the 5th European Rheology Conference, Portoroz, Slovenia, pp 487–488 (Sept 6–11)Google Scholar
  28. Münstedt H, Gabriel C, Auhl D (2003) Long-chain branching and elongational properties of polyethylene and polypropylene melts. Abstr Papers Am Chem Soc 226:U382–U382Google Scholar
  29. Münstedt H, Steffl T, Malmberg A (2005) Correlation between rheological behaviour in uniaxial elongation and film blowing properties of various polyethylenes. Rheol Acta 45(1):14–22CrossRefGoogle Scholar
  30. Münstedt H, Kurzbeck S, Stange J (2006) The importance of elongational properties of polymer melts for film blowing and thermoforming. Polym Eng Sci 46(9):1190–1195CrossRefGoogle Scholar
  31. Nishioka A, Takagi Y, Takahashi T, Masubuchi Y, Takimoto J, Koyama K (1998a) Measurement of biaxial elongational viscosity of polymer melts using lubricated squeezing flow method. J Soc Materials Science Japan 47(12):1296–1300Google Scholar
  32. Nishioka A, Takahashi T, Masubuchi Y, Takimoto J, Koyama K (1998b) Stress relaxation of polymer melts in biaxial and planar elongations. Mater Sci Res Int 4(2):121–123Google Scholar
  33. Nishioka A, Takahashi T, Masubuchi Y, Takimoto J-I, Koyama K (2000) Description of uniaxial, biaxial, and planar elongational viscosities of polystyrene melt by the K-BKZ model. J Non-Newton Fluid Mech 89(3):287–301CrossRefGoogle Scholar
  34. Nishioka A, Masubuchi Y, Takimoto J-I, Koyama K (2001) Measurement of planar elongational viscosity and planar stress relaxation of polymer melts using lubricated squeezing flow method. Seikei Kako 13(8):563–570CrossRefGoogle Scholar
  35. Piel C, Stadler FJ, Kaschta J, Rulhoff S, Münstedt H, Kaminsky W (2006) Structure-property relationships of linear and long-chain branched metallocene high-density polyethylenes and SEC-MALLS. Macromol Chem Phys 207(1):26–38CrossRefGoogle Scholar
  36. Schulze JS, Lodge TP, Macosko CW, Hepperle J, Münstedt H, Bastian H, Ferri D, Groves DJ, Kim YH, Lyon M, Schweizer T, Virkler T, Wassner E, Zoetelief W (2001) A comparison of extensional viscosity measurements from various RME rheometers. Rheol Acta 40(5):457–466CrossRefGoogle Scholar
  37. Schwetz M, Münstedt H, Heindl M, Merten A (2002) Investigations on the temperature dependence of the die entrance flow of various long-chain branched polyethylenes using laser-doppler velocimetry. J Rheol 46(4):797–815CrossRefGoogle Scholar
  38. Sentmanat ML (2004) Miniature universal testing platform: from extensional melt rheology to solid-state deformation behavior. Rheol Acta 43(6):657–669CrossRefGoogle Scholar
  39. Shroff R, Mavridis H (1999) Long-chain-branching index for essentially linear polyethylenes. Macromolecules 32(25):8454–8464CrossRefGoogle Scholar
  40. Soskey PR, Winter HH (1985) Equibiaxial extension of two polymer melts: polystyrene and low-density polyethylene. J Rheol 29(5):493–517CrossRefGoogle Scholar
  41. Stadler FJ, Piel C, Kaminsky W, Münstedt H (2006a) Rheological characterization of long-chain branched polyethylenes and comparison with classical analytical methods. Macromol Symp 236(1):209–218CrossRefGoogle Scholar
  42. Stadler FJ, Piel C, Kaschta J, Rulhoff S, Kaminsky W, Münstedt H (2006b) Dependence of the zero shear-rate viscosity and the viscosity function of linear high density polyethylenes on the mass-average molar mass and polydispersity. Rheol Acta 45(5):755–764CrossRefGoogle Scholar
  43. Stadler FJ, Piel C, Klimke K, Kaschta J, Parkinson M, Wilhelm M, Kaminsky W, Münstedt H (2006c) Influence of type and content of very long comonomers on long-chain branching of ethene-/α-olefin copolymers. Macromolecules 39(4):1474–1482CrossRefGoogle Scholar
  44. Stadler FJ, Takahashi T, Münstedt H, Yonetake K (2007a) Crystallite dimensions—characterization of ethene-/α-olefin copolymers with various comonomers and comonomer contents measured by small- and wide angle X-ray scattering. Polymer (in press)Google Scholar
  45. Stadler FJ, Takahashi T, Münstedt H, Yonetake K (2007b) Lattice sizes and spacing between amorphous chains—crystallite dimensions—characterization of ethene-/α-olefin copolymers with various comonomers and comonomer contents measured by wide angle X-ray scattering. Polymer (in press)Google Scholar
  46. Stange J, Münstedt H (2006) Effect of long-chain branching on the foaming of polypropylene with azodicarbonamide. J Cell Plast 42:445–467CrossRefGoogle Scholar
  47. Stange J, Uhl C, Münstedt H (2005) Rheological behavior of blends from a linear and a long-chain branched polypropylene. J Rheol 49(5):1059–1079CrossRefGoogle Scholar
  48. Sun T, Chance RR, Graessley WW, Lohse DJ (2004) A study of the separation principle in size exclusion chromatography. Macromolecules 37(11):4304–4312CrossRefGoogle Scholar
  49. Wagner MH (1978) A constitutive analysis of uniaxial elongational flow data of a low-density polyethylene melt. J Non-Newton Fluid Mech 4(1–2):39–55CrossRefGoogle Scholar
  50. Wagner MH, Bastian H, Hachmann P, Meissner J, Kurzbeck S, Münstedt H, Langouche F (2000) The strain hardening behaviour of linear and long-chain-branched polyolefin melts in extensional flows. Rheol Acta 39:97–109CrossRefGoogle Scholar
  51. Wagner MH, Yamaguchi M, Takahashi M (2003) Quantitative assessment of strain hardening of low-density polyethylene melts by the molecular stress function model. J Rheol 47(3):779–793CrossRefGoogle Scholar
  52. Wagner MH, Kheirandish S, Koyama K, Nishioka A, Minegishi A, Takahashi T (2005) Modeling strain hardening of polydisperse polystyrene melts by molecular stress function theory. Rheol Acta 44(3):235–243CrossRefGoogle Scholar
  53. Wood-Adams PM (2001) The effect of long chain branches on the shear flow behavior of polyethylene. J Rheol 45(1):203–210CrossRefGoogle Scholar
  54. Zimm BHM, Stockmayer WH (1949) The dimensions of molecules containing branching and rings. J Chem Phys 17(12):1301–1314CrossRefGoogle Scholar
  55. Zülle B, Linster JJ, Meissner J, Hürlimann HP (1987) Deformation hardening and thinning in both elongation and shear of a low-density polyethylene melt. J Rheol 31(7):583–598CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • F. J. Stadler
    • 1
    • 4
  • A. Nishioka
    • 2
  • J. Stange
    • 1
    • 3
  • K. Koyama
    • 2
  • H. Münstedt
    • 1
  1. 1.Institute of Polymer Materials, Department of Materials ScienceFriedrich-Alexander-University Erlangen-NürnbergErlangenGermany
  2. 2.Department of Polymer Science and EngineeringYamagata UniversityYonezawaJapan
  3. 3.Bayer Materials ScienceKrefeld-UerdingenGermany
  4. 4.Unité de Physique et de Chimie des Hauts PolymèresUniversité Catholique de LouvainLouvain-la-NeuveBelgium

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