Phase Behavior in Asymmetric Polymer Blends PDF Download

Author: Alisyn Jenise Nedoma
Publisher:
ISBN:
Category :
Languages : en
Pages : 258

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Author: Brian McLean Habersberger
Publisher:
ISBN:
Category :
Languages : en
Pages : 265

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Author: Karl Freed
Publisher: Springer Science & Business Media
ISBN: 9783540256809
Category : Technology & Engineering
Languages : en
Pages : 224

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Book Description

Author: Karl Freed
Publisher: Springer
ISBN: 9783540810186
Category : Technology & Engineering
Languages : en
Pages : 199

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Book Description

Author: Chen Kuang
Publisher:
ISBN:
Category : Polymers
Languages : en
Pages : 154

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Book Description
Phase separation in complex fluids such as polymers has been the subject of several experimental and theoretical studies in recent years. Understanding the phase separation mechanisms and controlling morphological evolution are very important for designing various advanced materials with novel mechanical, optical, electrical, and transport properties. In polymer blends, dynamic asymmetry is induced by a large difference in glass transition temperature. In this work, phase separation behavior of ternary blends of polystyrene/poly(vinyl methyl ether)/polyisoprene, PS/PVME/PI, and polystyrene/poly(vinyl methyl ether)/poly(ethyl methacrylate), PS/PVME/PEMA are investigated. Ternary blends of PS/PVME/PI and PS/PVME/PEMA exhibit complex phase separation behavior since PS and PVME have a lower critical solution temperature (LCST) behavior, while PI and PS (or PVME), PEMA and PS (or PVME) have upper critical solution temperature (UCST) behavior. 2D and 3D phase diagrams for these two ternary systems were plotted by both Flory-Huggins incompressible and regular solution compressible models. Casting the solutions of PS/PVME/PI and PS/PVME/PEMA blends form two phase-separated domains in most compositions: (i) PI-rich or PEMA rich, and (ii) PS/PVME-rich. Post-annealing of such samples leads to the second-stage phase separation due to unfavorable interaction of PS and PVME at temperatures about 100°C. Such behavior that is observed for the first time provides a new potential method for making different morphologies with the same system by changing annealing parameters and composition. Washing one polymer at a time using a selective solvent is used to study the morphology of ternary blends. Optical microscopy and scanning electron microscopy are used to study the kinetics and morphology of viscoelastic phase separation (VPS) in ternary blends.

Author: Piyawit Koombhongse
Publisher: LAP Lambert Academic Publishing
ISBN: 9783847329695
Category : Technology & Engineering
Languages : en
Pages : 0

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Book Description
The effect of flow is of industrial relevance in melt extrusion and injection molding where temperature gradients and high deformation rates are encountered. This demands a better understanding of the flow dependence of the phase behavior in polymer blends since the morphology and properties of the finished product are influenced to great extent by the details of dynamics of the flowing melt. Experimentally both shear induced mixing and shear induced demixing phenomena have been observed under a variety of operational conditions. The primary objective of this book is to explain the phase behavior under industrially realistic deformation rates using a partially miscible SAN/PMMA blend as an example and to clarify the effect of shear flow on morphology of injection-molded sample. The reader will briefly learn the basic Thermodynamics of phase separation, Thermodynamics of polymer blends, and how to detect polymer miscibility by using Raman Spectroscopy and other techniques. The effect of shear flow on phase behavior of polymer blend is demonstrated theoretically and experimentally.

Author: Narayan Prasad Adhikari
Publisher:
ISBN:
Category :
Languages : en
Pages : 104

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Book Description

Author: Daniel J. Duffy
Publisher:
ISBN:
Category : Phase partition
Languages : en
Pages : 684

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Author: Chŏng-ho Kim
Publisher:
ISBN:
Category : Polymerization
Languages : en
Pages : 442

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Book Description

Author: Michael M. Coleman
Publisher: Routledge
ISBN: 1351415158
Category : Technology & Engineering
Languages : en
Pages : 530

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Book Description
This book with software provides powerful tools for the analysis, prediction and creation of new polymer blends, an area of significant commercial potential. The R&D approaches and methods described in the book have attracted the interest of polymer R&D leaders in industry, and have been put into use in several major chemical companies. The companion set of computer programs speeds and facilitates work in this area. FROM THE AUTHORS' PREFACE: During the 1980's a steadily increasing number of compatible systems [polymer blends] have been reported. We believe that miscible mixtures will prove to be fairly common and the purpose of this book is to explore the circumstances in which single phase materials can be obtained. We will also describe a model for the phase behavior of these mixtures which we believe to have a predictive value, or be used as a practical guide to polymer miscibility. Our approach is based on the use of association models which have until recently been largely ignored in treating hydrogen bonding in polymer mixtures. They have most frequently been applied to mixtures of alcohols with simple hydrocarbons, where the equilibrium constants used to describe association have most frequently been determined by a fit to thermodynamic data (e.g., vapor pressures, heat of mixing). In our work we have sought to, first, adapt this approach to a description of the phase behavior of polymer mixtures; second, develop spectroscopic methods that provide an independent measurement of the equilibrium constants. Our purpose in this book is to explore and describe this approach and illustrate its broad utility. We address two overlapping yet different audiences. One would be primarily interested in the broad nature of this approach and the practical applications of a simple model. The second would be more interested in the derivations of the equations and some of the fundamental aspects of the spectroscopy of these systems. Accor