Morphological and rheological responses to the transient and steady shear flow for a phase-separated polybutadiene/polyisoprene blend

Abstract The morphological and rheological responses to the transient and steady shear flow for a phase-separated polybutadiene (PB)/low vinyl content polyisoprene (LPI) blend have been investigated. Under steady shear flow where the applied shear rate is not too large, the steady sheared structures become increasingly anisotropic and interconnected with an “en route” to the formation of string phases as shear rate increases. After that, the further increase of shear rate leads to a blurred domain interface. These shear-induced complex structures in turn affect the rheological response greatly and both the shear thinning and shear thickening were observed in the steady shear behavior of the phase-separated PB/LPI blend. Under transient shear flow, the time (or strain) dependence of viscosity and morphology after a shear rate jump were extensively studied in order to obtain the insight into the steady state formation and found to be mainly determined by the final shear rates. Depending on whether the transient string phases which were formed by the transient shear flow can be stabilized and with clear domain interface, three kinds of transient shear viscosity changes have been observed. Some of the observations are quite different from the model immiscible blend and believed to be closely related to the significant shear-induced mixing effect happened in the PB/LPI blend.

[1]  Akira Onuki.  Phase transitions of fluids in shear flow , 1997 .

[2]  A. Nakatani,et al.  Phase Inversion of Polybutadiene/Polyisoprene Blends under Quiescent and Shear Conditions , 2001 .

[3]  D. Vlassopoulos,et al.  Microstructural changes of a binary polymer blend in simple shear flow across the phase boundary , 2003 .

[4]  I. Noda,et al.  Viscoelastic Properties of Immiscible Polymer Blends under Steady and Transient Shear Flows , 1994 .

[5]  M. Doi,et al.  Experimental tests of the scaling relation for textured materials in mixtures of two immiscible fluids , 1994 .

[6]  Wei-Chung Yu,et al.  A simple constitutive equation for immiscible blends , 2007 .

[7]  Rosario E. S. Bretas,et al.  Rheology of polymer blends: non-linear model for viscoelastic emulsions undergoing high deformation flows , 2001 .

[8]  Ronald G. Larson,et al.  Flow-induced mixing, demixing, and phase transitions in polymeric fluids , 1992 .

[9]  R. Weiss,et al.  Flow-induced mixing and demixing in polymer blends , 1992 .

[10]  Yuan-ze Xu,et al.  Rheology of Concentrated Blends with Immiscible Components , 2005 .

[11]  P. Carreau,et al.  Relationships between rheology and morphology for immiscible molten blends of polypropylene and ethylene copolymers under shear flow , 1998 .

[12]  N. Grizzuti,et al.  Effects of coalescence and breakup on the steady-state morphology of an immiscible polymer blend in shear flow , 1997 .

[13]  W. R. Schowalter,et al.  Rheological properties of nondilute suspensions of deformable particles , 1975 .

[14]  C. Han,et al.  Melt rheology of lower critical solution temperature polybutadiene/ polyisoprene blends , 2000 .

[15]  D. Pine,et al.  Structure Evolution of a Polymer Solution at High Shear Rates , 1996 .

[16]  D. Baird,et al.  An evaluation of the Doi–Ohta theory for an immiscible polymer blend , 1996 .

[17]  J. Mewis,et al.  Transient stresses in immiscible model polymer blends during start-up flows , 2001 .

[18]  J. Mewis,et al.  Relationship between rheology and morphology of model blends in steady shear flow , 1996 .

[19]  D. J. Stout,et al.  Shear-induced structure in polymer blends with viscoelastic asymmetry , 2002 .

[20]  Heh Han Meijer,et al.  Droplet breakup mechanisms : stepwise equilibrium versus transient dispersion , 1993 .

[21]  A. Silberberg,et al.  Miscibility of Liquids Influenced by Rate of Shear , 1952, Nature.

[22]  O. Park,et al.  Rheology and dynamics of immiscible polymer blends , 1994 .

[23]  Onuki.  Viscosity enhancement by domains in phase-separating fluids near the critical point: Proposal of critical rheology. , 1987, Physical review. A, General physics.

[24]  J. Mewis,et al.  Transient rheological response and morphology evolution of immiscible polymer blends , 1997 .

[25]  A. Onuki,et al.  Elastic effects in the phase transition of polymer solutions under shear flow. , 1989, Physical review letters.

[26]  E. K. Hobbie,et al.  Droplet breakup and shear-induced mixing in critical polymer blends , 1997 .

[27]  Charles C. Han,et al.  Relaxation behavior of polymer blends after the cessation of shear , 2000 .

[28]  C. L. Tucker,et al.  Microstructural evolution in polymer blends , 2003 .

[29]  R. Larson,et al.  A constitutive model for the prediction of ellipsoidal droplet shapes and stresses in immiscible blends , 2000 .

[30]  K. Kawasaki,et al.  Fluctuations in Nonequilibrium Steady States with Laminar Shear Flow: Classical Fluids near the Critical Point , 1978 .

[31]  G. Fuller,et al.  Flow-induced concentration fluctuations in polymer solutions: Structure/property relationships , 1993 .

[32]  T. Koga,et al.  RHEOLOGICAL RESPONSE FROM PHASE-SEPARATED DOMAINS AS STUDIED BY SHEAR MICROSCOPY , 1998 .

[33]  I. Noda,et al.  Rheological properties and domain structures of immiscible polymer blends under steady and oscillatory shear flows , 1997 .

[34]  Helfand,et al.  Large fluctuations in polymer solutions under shear. , 1989, Physical review letters.

[35]  L. Utracki.  On the viscosity‐concentration dependence of immiscible polymer blends , 1991 .

[36]  N. Martys,et al.  Critical properties and phase separation in lattice Boltzmann fluid mixtures. , 2001, Physical review. E, Statistical, nonlinear, and soft matter physics.

[37]  D. Vlassopoulos,et al.  Shear-induced mixing and demixing in poly(styrene- co-maleic anhydride)/poly(methyl methacrylate) blends , 1998 .

[38]  Milner.  Hydrodynamics of semidilute polymer solutions. , 1991, Physical review letters.

[39]  Takao Ohta,et al.  Dynamics and rheology of complex interfaces. I , 1991 .

[40]  Tadashi Inoue,et al.  Shear small-angle light scattering studies of shear-induced concentration fluctuations and steady state viscoelastic properties. , 2008, The Journal of chemical physics.

[41]  G. Fuller,et al.  Rheo-optical studies of shear-induced structures in semidilute polystyrene solutions , 1997 .

[42]  J. Egmond,et al.  Structure and dynamics of a polymer solution subject to flow-induced phase separation , 1991 .

[43]  N. Clarke,et al.  Shear-Induced Demixing in Polystyrene/Poly(vinyl methyl ether) Blends. 1. Early Stages of Shear-Induced Demixing , 1999 .

[44]  D. Hoagland,et al.  Light scattering from dilute poly(styrene) solutions in uniaxial elongational flow , 1991 .

[45]  C. Han,et al.  Effect of Shear Flow on Multi-Component Polymer Mixtures , 2006 .

[46]  K. Kawasaki,et al.  Nonequilibrium steady state of critical fluids under shear flow: A renormalization group approach , 1979 .

[47]  C. Han,et al.  Shear light scattering photometer with optical microscope for the study of polymer blends , 1996 .

[48]  Moses,et al.  Shear microscopy of the "butterfly pattern" in polymer mixtures. , 1994, Physical review letters.

[49]  T. Hashimoto,et al.  Ordered structure and critical phenomena of a semidilute solution of polymer mixtures under shear flow , 1988 .

[50]  W. Li,et al.  Shear Induced Phase Boundary Shift in the Critical and Off-Critical Regions for a Polybutadiene/Polyisoprene Blend , 2012 .

[51]  Kim,et al.  Stringlike patterns in critical polymer mixtures under steady shear flow. , 1996, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[52]  J. Higgins,et al.  Complex miscibility behaviour for polymer blends in flow , 1995 .