Polymer morphology imaging techniques

Imaging techniques provide invaluable information on the morphology of polymers and nanocomposites. Of course an imaging technique is able to provide information on the spatial distribution of the structure and morphology. Each of the techniques considered here has particular advantages as well as specific sample preparation requirements. It is probable that the techniques employed in a particular project are selected as a consequence of the resolution matching the requirements, otherwise all techniques should be considered useful and effective especially when used in combination. 

As described below, the HAS-derived nitroxides in heterophasic polymer systems perform a triple role. First, they provide the contrast needed in the imaging experiments. Second, they enable the visualization of polymer morphology, based on the detection of two dynamically different components detected in the ESR spectra of the nitroxides in ABS, for example, the two sites, fast (F) and slow (S), have been assigned to location of nitroxides in butadiene-rich and styrene-acrylonitrile (SAN)-rich domains, respectively. Third, the spatial variation of the ESR spectra of nitroxides (in terms of intensity and line shapes) with treatment time, t, provides detailed information on the extent of degradation in the different miCTodomains. These experiments made possible the determination of the concentration profiles of the nitroxides from ID ESRl, and also of the spectral profiles from 2D spectral-spatial ESRI, both in a nondestructive way. In these studies the nitroxides, which are the contrast agents, are part of the systan therefore these studies represent the evolution of ESRl techniques beyond phantoms. 

This Chapter describes the use of both point mapping and global imaging techniques to study subtle spatial variations in polymer chemistry and morphology. Mapping and imaging of additives and crystallinity/molecular orientation in polymer articles will be illustrated [384]. Quantitative acoustic microscopy was reviewed [385] as well as scanning acoustic microscopy [386-388]. Laser ablation mi-croanalytical techniques are discussed in Chp. 3. 

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