Internal Reorganization of Agglomerates as an Explanation of Energy Dissipation at Very Low Strain for Heterogeneous Polymer Systems

2011 ◽  
Vol 21 (2) ◽  
pp. 113-119 ◽  
Author(s):  
Jean-Charles Majesté ◽  
Christian Carrot ◽  
Beatriz Olalla ◽  
René Fulchiron
Keyword(s):  
Energy Dissipation ◽  
Polymer Systems ◽  
Heterogeneous Polymer

Characterization of Multi-Phase and Multi-Component Polymer Systems Using the Atomic Force Microscope

1999 ◽  
Vol 5 (S2) ◽  
pp. 962-963
Author(s):  
M. VanLandingham ◽  
X. Gu ◽  
D. Raghavan ◽  
T. Nguyen
Keyword(s):  
Energy Dissipation ◽  
Atomic Force Microscope ◽  
Mechanical Response ◽  
Sample Surface ◽  
Phase Changes ◽  
Phase Imaging ◽  
Polymer Systems ◽  
Atomic Force ◽  
Phase Images ◽  
Multi Phase

Recent advances have been made on two fronts regarding the capability of the atomic force microscope (AFM) to characterize the mechanical response of polymers. Phase imaging with the AFM has emerged as a powerful technique, providing contrast enhancement of topographic features in some cases and, in other cases, revealing heterogeneities in the polymer microstructure that are not apparent from the topographic image. The enhanced contrast provided by phase images often allows for identification of different material constituents. However, while the phase changes of the oscillating probe are associated with energy dissipation between the probe tip and the sample surface, the relationship between this energy dissipation and the sample properties is not well understood.As the popularity of phase imaging has grown, the capability of the AFM to measure nanoscale indentation response of polymers has also been explored. Both techniques are ideal for the evaluation of multi-phase and multi-component polymer systems.

Raman Imaging of Heterogeneous Polymers: A Comparison of Global versus Point Illumination

1995 ◽  
Vol 49 (10) ◽  
pp. 1411-1430 ◽  
Author(s):  
Lars Markwort ◽  
Bert Kip ◽  
Edouard Da Silva ◽  
Bernard Roussel
Keyword(s):  
Global Illumination ◽  
Depth Resolution ◽  
Raman Imaging ◽  
Alternative Methods ◽  
Wide Field ◽  
Light Collection ◽  
Polymer Systems ◽  
Heterogeneous Polymer ◽  
Scattering Effects ◽  
Heterogeneous Polymers

Two alternative methods of Raman imaging, via global (wide-field) illumination and via point illumination in combination with confocal light collection, have been applied to the study of heterogeneous polymer systems. From the results obtained it becomes apparent that the fluorescence inherent to most polymer systems severely limits the use of global illumination. Furthermore, the lack in depth resolution in Raman imaging by global illumination ruled out this method for the study of bulk polymer samples. Also as a consequence of the absence of depth resolution, the global illumination technique appeared more vulnerable to artifacts arising from scattering effects due to the sample geometry and fluorescence. Hence, for a general application of Raman imaging to the study of polymer samples, Raman imaging by point illumination in conjunction with confocal light collection is the method of choice

A method for analysing proton NMR relaxation data from motionally heterogeneous polymer systems

1998 ◽  
Vol 12 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Marco Geppi ◽  
Robin K. Harris ◽  
Alan M. Kenwright ◽  
Barry J. Say
Keyword(s):  
Proton Nmr ◽  
Nmr Relaxation ◽  
Relaxation Data ◽  
Polymer Systems ◽  
Heterogeneous Polymer

Miscibility Studies on Heterogeneous Polymer Blends by Radioluminescence Spectroscopy and Particle Coarsening Measurements

1977 ◽  
Vol 50 (4) ◽  
pp. 714-722 ◽  
Author(s):  
G. G. A. Böhm ◽  
K. R. Lucas ◽  
W. G. Mayes
Keyword(s):  
Rare Event ◽  
Polymeric Composite ◽  
State Theory ◽  
Degree Of Polymerization ◽  
Solution Temperature ◽  
Subtle Difference ◽  
Polymer Systems ◽  
Physical Strength ◽  
Heterogeneous Polymer ◽  
Polymer Miscibility

Abstract Interest in the subject of polymer miscibility has been stimulated by the investigation and common use by industry of heterogeneous polymer systems. Particularly, in recent years we have seen the development of materials, such as ABS, high-impact polystyrene, block copolymers, thermoplastic elastomer blends (TPR, etc.), and many more, which owe their unique properties to a certain critical degree of immiscibility of the polymeric constituents. This subtle difference in miscibility contributes to the formation of morphological features in the above-mentioned materials. More importantly, it governs the adhesion between the domains of the phase-separated polymeric composite. The latter property provides for stress transfer across the interface and thus is needed for the attainment of physical strength. Thus the questions posed by researchers are not so much concerned with whether two polymers are fully miscible on a molecular scale, a rare event indeed, but rather in the degree of miscibility of the two materials. In spite of recent advances made, the bulk miscibility of polymers cannot be predicted by theory. The lattice theory of Flory leads to unsatisfactory conclusions. It can, however, be used for an after-the-fact representation of experimental findings by use of an empirically determined concentration- and temperature-dependent polymer interaction coefficient. More insight and qualitative postulates on polymer miscibility are provided by the equation-of-state theory. It correctly predicts the marked influence of the degree of polymerization and of the thermal expansion and pressure coefficients and, more importantly, it anticipates the lower critical solution temperature observed in a number of polymer systems. However, the equations are complicated and contain many generally unknown, but experimentally accessible, parameters, and thus this theory too is of little help to the investigator seeking miscibility data for a specific pair of polymers.

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