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Shear influences on polymer blends: experimental, theoretical approaches and technical implications
Author(s) -
Higgins Julia S.,
Gerard Hervé,
Vlassopoulos Dimitris,
Horst Roland,
Wolf Bernhard A.
Publication year - 2000
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/1521-3900(200001)149:1<165::aid-masy165>3.0.co;2-x
Subject(s) - materials science , polystyrene , methyl methacrylate , polymer blend , polymer , shear flow , polymer chemistry , rheology , thermodynamics , composite material , copolymer , physics
We examine the effects of shear on polymer blends consisting of partially miscible components, i.e. systems close to the phase boundary. The eminent phenomenon is the shift of the phase boundary, either extending the homogeneous area (flow‐induced mixing) or the opposite effect (flow‐induced demixing). The kinetics of the demixing process and concentration fluctuations are also influenced by flow fields, inducing anisotropy due to the flow direction. Experiments (scattering, rheology, in‐situ flow‐scattering, microscopy, DSC) are carried out with the academic model blend polystyrene/poly(vinyl methyl ether) and the industrial poly(styrene‐co‐maleic anhydride)/poly (methyl methacrylate) blend. The experimental results are rationalised in terms of a generalised Gibbs energy of mixing by including the energy which is stored in the sheared fluids.