Development of Characteristic Morphologies During Preparation

Morphological structures and properties of a series of poly(ethyl acrylate)/clay nanocomposites prepared by the two distinctively different techniques of in situ ATRP and solution blending were studied by Datta et al. [79]. Tailor-made PNCs with predictable molecular weights and narrow polydispersity indices were prepared at different clay loadings. WAXD and studies revealed that the in situ approach is the better option because it provided an exfoliated morphology. By contrast, conventional solution blending led only to interlayer expansion of the clay gallery. 

The dispersion behavior of organoclay affected the visual appearance of the hybrid composites (Fig. 6a, b). The composites containing Si particles predominantly as a finely dispersed phase were transparent, e.g., PNCI2 [nanocomposite prepared in 

The same group carried out ATRP of EA in bulk at 90°C in the presence of organically modified nanoclay as an additive. They found remarkable enhancement in the rate of polymerization as compared with the ATRP of EA without nanoclay. Interestingly, the resulting nanocomposites had exfoliated clay particles, as evident from WAXD and studies [80]. 

The necessity of dispersion of nanofillers for enhancement of properties of nanocomposites has been well-documented. Literature describes various techniques used for preparation of the rubber-based nanocomposites [5]. These processes have their inherent pros and cons, but seldom have these issues been quantitatively documented or the processes combined together to synergize and overcome the failings of a technique. 

Sadhu et al. [88] reported interesting observations when they processed their nanocomposites through a capillary using the Monsanto Processability Tester. They found that different morphologies were formed and more ordering took place because of the shearing of the nanocomposites through the capillary. 

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