Techniques for Studying Blend Microstructure

Experimental study of blend miscibility or compatibility is more difficult for polymeric materials than for small molecules, because the heat of mixing (A/Z ) is very small for polymers and is nearly impossible to measure directly. Because of the microscopic size of the dispersed phase, it is necessary to use special techniques to measure morphology on that very small scale. A brief sampling of the most important techniques used to study blend microstructure is offered below [6]. 

Measurement of the glass transition temperature of a blend is one of the most common ways to determine blend compatibility. Perhaps the most used criterion of polymer 

Scanning electron microscopy (SEM) can offer a good depth of held, good resolution, and easy specimen preparation. It can be used for immiscible polymer blends, where the phases are sufficiently large and can be easily debonded. Information on surface topography, size, and distribution of the dispersed phase and interfacial interaction between phases can be elucidated with this technique. Elemental analysis on the blend components can also be obtained if the SEM equipment includes an energy dispersion X-ray spectrometer (EDX). 

Another microscopic technique is transmission electron microscopy (TEM), which offers higher resolution and 

This technique can be used to obtain structural information on very small scales approaching the molecular dimensions. It can be used to study surface morphology, internal structure, and crystallographic analysis. It can provide information about cocrystallization, very fine depression phases, or interfaces. 

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