Structural changes during processing

An important feature of filled elastomers is the stress softening whereby an elastomer exhibits lower tensile properties at extensions less than those previously applied. As a result of this effect, a hysteresis loop on the stress-strain curve is observed. This effect is irreversible it is not connected with relaxation processes but the internal structure changes during stress softening. The reinforcement results from the polymer-filler interaction which include both physical and chemical bonds. Thus, deforma-tional properties and strength of filled rubbers are closely connected with the polymer-particle interactions and the ability of these bonds to become reformed under stress. 

V. H NMR Investigations of Partially Oxygenated Species of Hemoglobin Evidence for Nonconcerted Structural Changes during the Oxygenation Process... 

Electron transfer reactions are categorized as outer or inner sphere. In outer-sphere processes, structural changes during ET largely involve solvent reorientation (polarization). Inner-sphere reactions involve changes in the bonding to the redox unit and are more difficult to describe using the ET theory as it is explained here. 

Several methods can be used to determine the necessary freezing speed, the required temperature at the end of the freezing process, the sublimation temperature and the structural changes that take place if the solidified product is kept for some time at a certain temperature. These methods will also show the influence of CPAs. Some of these methods can also be used to study structural changes during storage of the dried product. 

Comparing the results obtained with 27A1 MAS NMR to those obtained by i29Xe NMR, a coincidence between both techniques can be appreciated since both indicate that the extra-lattice A1 suffers a structural change during the chemical reaction, which leads to a partial blocking of the side-pockets thus contributing to the observed deactivation process. 

Structural changes during the creep process of ultrahigh-strength polyethylene fiber (UHSPE) were investigated using X-ray and the solid-state NMR techniques. As the creep strain increases, the quantity of the amorphous phase area estimated by the NMR method increases until the final creep rupture. " ... 

The size of the structural elements often determines or greatly affects several properties of a dispersed system. This concerns changes during processing and storage as well as static properties of the finished product. Below, some examples of dependencies on scale will be given, for the most part illustrated for simple dispersions. 

Structural and Compositional Changes During Processing of Dry Beans (Phaseolus... 

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