Rheological investigation of form relaxation and interface relaxation processes in polymer blends

1996 ◽  
Vol 36 (5) ◽  
pp. 637-643 ◽  
Author(s):  
R. -E. Riemann ◽  
H. -J. Cantow ◽  
C. Friedrich
Keyword(s):  
Polymer Blends ◽  
Relaxation Processes

Dynamic mechanical properties of crystalline polymer blends. The influence of interface and orientation

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Andrzej Galeski
Keyword(s):  
Glass Transition ◽  
Polymer Blends ◽  
Amorphous Phase ◽  
Molecular Orientation ◽  
Temperature Shift ◽  
Crystalline Polymer ◽  
Intensity Change ◽  
Relaxation Processes ◽  
Dynamic Mechanical ◽  
Compatibilized Blends

AbstractModification of the interface changes the viscoelastic response of crystalline polymer blends. For incompatible systems, usually one or more additional tan δ (mechanical loss) peaks appear which reflect the embrittlement of the material. Upon proper compatibilization, the additional peaks disappear and the material becomes tougher. The associated phenomena are explained and illustrated by a number of examples including polypropylene filled with calcium carbonate, polyethylene (PE) and polystyrene compatibilized blends, compatibilized blends of poly(ethylene terephthalate) (PET) with polyethylene as well as polyamide 6/polypropylene- graft-acrylic acid blends. Modes of deformation producing cavitation and cavity free deformation were applied to polymer blends in order to study the influence of molecular orientation and the presence of cavities. It is concluded that interfaces between blend components are weak elements of the blends even in the presence of a compatibilizer. Dynamic mechanical analysis (DMTA) evidenced the occurrence of interactions of the compatibilizer with blend components through temperature shift and intensity change of α, β and γ relaxation processes of polymer components. In oriented films of PET/high-density PE compatibilized blends, the chain segments in the amorphous phase of PET are oriented along machine direction. However, there is a significant anisotropy of chain packing in the plane perpendicular to the drawing direction - the pseudohexagonal packing of chain fragments being in register over the whole film. The PET amorphous phase exhibits anisotropy: DMTA studies show that the glass transition occurs at different temperatures while bending the film in different directions. The source of the ‘anisotropy’ in glass transition is the anisotropy of the amorphous phase: the pseudohexagonal packing and the orientation of chain segments. It is evident that the free volume and frozen fraction of the amorphous phase exhibit some degree of anisotropy. In highly compressed samples free of cavities, the glass transition temperature is shifted to higher temperature as compared to undeformed or drawn and cavitated blends. The shift is the result of high molecular orientation of the amorphous phase of matrix polymer and of the stabilization effect of unbroken interfaces in compressed samples.

Comparison between morphology and relaxation processes in partially phase-separated polymer blends

Polymer ◽  
1989 ◽  
Vol 30 (1) ◽  
pp. 3-10 ◽  
Author(s):  
M.L. Fernandez ◽  
J.S. Higgins ◽  
P.E. Tomlins
Keyword(s):  
Polymer Blends ◽  
Relaxation Processes

Microscopic Relaxation Processes in Branched-Linear Polymer Blends by Rheo-SANS

2013 ◽  
Vol 46 (22) ◽  
pp. 9122-9133 ◽  
Author(s):  
N. Ruocco ◽  
L. Dahbi ◽  
P. Driva ◽  
N. Hadjichristidis ◽  
J. Allgaier ◽  
...  
Keyword(s):  
Polymer Blends ◽  
Linear Polymer ◽  
Relaxation Processes

scholarly journals Viscoelastic effects in relaxation processes of concentration fluctuations in dynamically asymmetric polymer blends

2002 ◽  
Vol 65 (2) ◽  
Author(s):  
Mikihito Takenaka ◽  
Hiroyuki Takeno ◽  
Hirokazu Hasegawa ◽  
Shin Saito ◽  
Takeji Hashimoto ◽  
...  
Keyword(s):  
Polymer Blends ◽  
Concentration Fluctuations ◽  
Relaxation Processes ◽  
Viscoelastic Effects

Integration of Core-Edge Spectroscopy Methods for the Study of Polymers

1996 ◽  
Vol 54 ◽  
pp. 154-155
Author(s):  
E. G. Rightor
Keyword(s):  
Excited State ◽  
Polymer Blends ◽  
Gas Phase ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Electronic States ◽  
Core Electron ◽  
Bulk Solids ◽  
Development Application

Core edge spectroscopy methods are versatile tools for investigating a wide variety of materials. They can be used to probe the electronic states of materials in bulk solids, on surfaces, or in the gas phase. This family of methods involves promoting an inner shell (core) electron to an excited state and recording either the primary excitation or secondary decay of the excited state. The techniques are complimentary and have different strengths and limitations for studying challenging aspects of materials. The need to identify components in polymers or polymer blends at high spatial resolution has driven development, application, and integration of results from several of these methods.

A quantitative image analysis method for the determination of cocontinuity in polymer blends

1993 ◽  
Vol 51 ◽  
pp. 894-895
Author(s):  
William A. Heeschen
Keyword(s):  
Image Analysis ◽  
Polymer Blends ◽  
Quantitative Measurement ◽  
Morphological Evolution ◽  
Phase Ratio ◽  
Irregular Shapes ◽  
Quantitative Image ◽  
Discrete Domains ◽  
A Domains

Two new morphological measurements based on digital image analysis, CoContinuity and CoContinuity Balance, have been developed and implemented for quantitative measurement of morphology in polymer blends. The morphology of polymer blends varies with phase ratio, composition and processing. A typical morphological evolution for increasing phase ratio of polymer A to polymer B starts with discrete domains of A in a matrix of B (A/B < 1), moves through a cocontinuous distribution of A and B (A/B ≈ 1) and finishes with discrete domains of B in a matrix of A (A/B > 1). For low phase ratios, A is often seen as solid convex particles embedded in the continuous B phase. As the ratio increases, A domains begin to evolve into irregular shapes, though still recognizable as separate domains. Further increase in the phase ratio leads to A domains which extend into and surround the B phase while the B phase simultaneously extends into and surrounds the A phase.

Short Communication: Synthesis of Polymer-Embedded Metal Clusters by Thermolysis of Mercaptides—Polymer Blends

Polymer News ◽  
2005 ◽  
Vol 30 (9) ◽  
pp. 296-300
Author(s):  
F. Esposito ◽  
V. Casuscelli ◽  
M. V. Volpe ◽  
G. Carotenuto ◽  
L. Nicolais
Keyword(s):  
Polymer Blends ◽  
Short Communication ◽  
Metal Clusters ◽  
Communication Synthesis
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