Micro/Nano Structure and Morphology of Multi-Phase Polymer/Oxide Composites Prepared by Powder Melt Processing

2011 ◽  
Vol 1297 ◽  
Author(s):  
Giorgiana Giancola ◽  
Richard Lehman
Keyword(s):  
Polymer Blends ◽  
Polymer Processing ◽  
Melt Processing ◽  
Immiscible Polymer Blends ◽  
Nano Structure ◽  
Shear Rates ◽  
High Shear Rates ◽  
Multi Phase ◽  
Processing Techniques ◽  
Electron Imaging

ABSTRACTPowder polymer processing techniques were evaluated as a means to generate homogeneous immiscible polymer blends without the high residence times at elevated temperature and high shear rates required by extrusion. Using emulsion polymerized and cryogenically jet pulverized PMMA and HDPE powder precursors, blends were prepared with morphologies comparable to extruded blends. Advanced EDS imaging methods combined with SiO2 marker spheres enhanced electron imaging and analysis of all blend phases. These processing methods will be useful in producing polymer blends from fragile polymers, such as those used in biomedical applications, that cannot tolerate the temperature or shear rates of conventional melt processing.

Shear Induced Phase Behavior of Polymer Blends by Small Angle Neutron Scattering

1989 ◽  
Vol 166 ◽  
Author(s):  
Alan I. Nakatani ◽  
Hongdoo Kim ◽  
Charles C. Han
Keyword(s):  
Neutron Scattering ◽  
Polymer Blends ◽  
Phase Behavior ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Large Body ◽  
Concentric Cylinder ◽  
Shear Rates ◽  
Lower Shear ◽  
High Shear Rates

ABSTRACTThe phase behavior of polymer blends and solutions can be changed dramatically by a flow field using a variety of flow geometries. Unlike simple binary fluids which require extremely high shear rates to produce only small shifts in the phase boundary, polymer phase behavior may be influenced by as much as 10 degrees with the application of much lower shear rates. However, there is a large body of conflicting data concerning the nature of these shear effects in polymers.Here we report on the effects of shear on the phase behavior of polymer blends by small angle neutron scattering (SANS). Experiments were conducted using a specially constructed, concentric cylinder apparatus for in situ studies of concentrated polymer solutions and melts. Two separate systems will be discussed: 1) a blend of polystyrene and polybutadiene. 2) a blend of polystyrene and poly(vinylmethylether). Both systems exhibit shifts in the phase behavior which indicate shear induced mixing in agreement with previous results obtained by other techniques. These results will be interpreted within the context of existing theories of shear induced phase behavior.

scholarly journals RHEOLOGICAL PROPERTIES OF MIXTURES OF RANDOM POLYPROPYLENE WITH BUTADIENE-NITRILE RUBBER AND VULCANIZATES BASED ON THEM

2021 ◽  
pp. 23-29
Author(s):  
A.J. Quliyev ◽  
◽  
N.T. Kakhramanov ◽  
N.S. Koseva ◽  
N.B. Arzumanova ◽  
...  
Keyword(s):  
Polymer Blends ◽  
Effective Viscosity ◽  
Nitrile Rubber ◽  
High Shear ◽  
Processing Conditions ◽  
Flow Curves ◽  
Shear Rates ◽  
High Shear Rates ◽  
Invariant Characteristic ◽  
Butadiene Nitrile Rubber

The paper presents the results of studying the effects of butadiene-nitrile rubber concentration and temperature on the flow curves of the random polypropylene-based polymer blends. To improve the technological compatibility of polymer blends, a graft(ed) copolymer of polypropylene with maleic anhydride was used as a compatibilizer. Melt viscosity as a function of temperature and shear rate is shown, and the activation energy of a viscous flow has been defined. A generalized temperature-invariant characteristic of the viscosity properties of polymer blends has been plotted. This makes it possible to predict the value of their effective viscosity at high shear rates, close to real processing conditions

Electrically Conducting Polymer Blends Based On Polyaniline

1995 ◽  
Vol 413 ◽  
Author(s):  
P. Passiniemi ◽  
J. Laakso ◽  
H. Ruohonen ◽  
Kimmo Väkiparta
Keyword(s):  
Polymer Blends ◽  
Conducting Polymer ◽  
Polymer Processing ◽  
Melt Processing ◽  
Fiber Spinning ◽  
Compression Moulding ◽  
Electrically Conducting ◽  
Thermoset Resins ◽  
The Matrix ◽  
Maximum Conductivity

ABSTRACTPolyaniline offers a promissing possibility to make electrically conducting polymer blends with tailorable surface and bulk conductivities. The matrix polymer can be a thermoplast or a thermo- set. Different commonly used polymer processing methods are applicable to the blends; e.g. injection moulding, film blowing, compression moulding and fiber spinning. Also commonly used thermoset resins processings are possible. The key feature in making all this feasible is the co- solvent/plasticizer technology developed recently in the industry. Typically, the antistatic conduc- tivity level is reached in melt-processing with a polyaniline complex amount of 5 to 10 wt-% and in solution processing with 0.5 to 5 wt-% complex amounts. The maximum conductivity is in the range of 10 to 100 mS/cm for blends.

Rheology and Processing of Polymeric Materials: Volume 2: Polymer Processing

2006 ◽  
Author(s):  
Chang Dae Han
Keyword(s):  
Polymer Blends ◽  
Polymeric Materials ◽  
Polymer Processing ◽  
Fiber Spinning ◽  
Immiscible Polymer Blends ◽  
Thermoset Composites ◽  
Single Screw Extrusion ◽  
Reaction Injection Molding ◽  
Screw Extrusion ◽  
Wire Coating

Volume 2 presents the fundamental principles related to polymer processign operations including the processing of thermoplastic polymers and thermosets. The objective of this volume is not to provide recipies that necessarily guarantee better product quality. Rather, emphasis is placed on presenting a fundamental approach to effectively analyze processing operations. The specific polymer processing operations for thermoplastics include plasticating single-screw extrusion, morphology evolution during compounding of polymer blends, compatibilization of immiscible polymer blends, wire coating extrusion, fiber spinning, tubular film blowing, coextrusion, and thermoplastic foam extrusion. The specific polymer processing operations for thermosets include reaction injection molding, pultrusion of fiber-reinforced thermosets, and compression molding of thermoset composites.

Modeling and Simulation of the Phase Coarsening Process for Cocontinuous Polymer Blends

2020 ◽  
Author(s):  
Hangming Shen ◽  
Donggang Yao
Keyword(s):  
Polymer Blends ◽  
Structural Control ◽  
Computational Models ◽  
Flow Model ◽  
Moving Boundary ◽  
Load Transfer ◽  
Melt Processing ◽  
Immiscible Polymer Blends ◽  
Phase Coarsening ◽  
Coarsening Kinetics

Abstract Among different phase structures in immiscible polymer blends, the cocontinuous phase structure is considered to be advantageous for load transfer and achieving good mechanical properties. Due to the presence of an interpenetrating interface, phase coarsening naturally occurs during melt processing of cocontinuous polymer blends, and harness of the coarsening kinetics is important for structural control. Existing models for phase coarsening are mostly founded on the basis of scaling or dimensional analysis while computational models embodying more realistic phase geometries are demanded. In this paper, we present a two-step computational approach for prediction of the coarsening kinetics. First, a phase-field transport equation is solved to establish an initial phase geometry. Second, a moving-boundary flow model is implemented to solve the hydrodynamic problem. Case studies are presented both in 2D and in 3D domains. An empirical model on the basis of fractional calculus is also proposed to fit the computational results. Once verified by experimental data, this approach can provide an integrated tool for assisting in the processing of cocontinuous polymer blends where phase coarsening is of concern.

Morphological effects on Glass Transitions in Immiscible Polymer Blends

2004 ◽  
Vol 856 ◽  
Author(s):  
Vivek M. Thirtha ◽  
Richard L. Lehman ◽  
Thomas J. Nosker
Keyword(s):  
Glass Transition ◽  
Polymer Blends ◽  
Volume Fraction ◽  
Glassy Polymers ◽  
Melt Processing ◽  
Modulated Dsc ◽  
Systematic Change ◽  
Scanning Calorimetry ◽  
Immiscible Polymer Blends ◽  
Immiscible Polymer

ABSTRACTThis paper describes the effects of structures on the glass transition of glassy polymers blended with a semi-crystalline polymer. Immiscible blends of PS/PP and PS/HDPE were prepared from commercially available polymers using melt processing and extrusion without additives. The weight fractions of the components were varied from 0 to 1. SEM analysis of the blends showed a range of morphologies over the composition range from small inclusions at low volume concentrations through intertwined co-continuous structures at specific intermediate compositions, and a reversal of this configuration at high volume fractions. The glass transition of the glassy polymer was measured with differential scanning calorimetry using the sensitive and high resolution modulated DSC method. A systematic change in glass transition of glassy polymers is observed as a function of composition in various immiscible polymer blends. Results show that the glass transition of polystyrene increases with a reduction in volume fraction, by approximately 5.4°C in polypropylene and 6.5°C in polyethylene. Probable models which might explain this effect are mentioned.

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