Properties of SPS nanocomposites

When a thermally stable organoclay treated with alkyl phosphonium is used [15], there is no reason to reduce the mechanical properties since no amorphous styrenics are added. Instead, there would be increasing tendencies of 

Abbreviation SPS (wt %) Amorphous Styrenic Polymer (wt %) Organoclay, 15 A (wt %) Fabrication Method d-Spacing (nm) 

SPS nanocomposites exhibited an enhanced crystallization rate but had reduced crystallization than the neat polymer. The reason is that clay dispersed in the polymer matrix may serve as a nucleating agent but also hinders the crystal growth of polymer chains as a foreign material [14]. Exfoliated nanocomposites exhibited a faster crystallization and a lower degree of crystallization than intercalated ones. It is quite reasonable since clay in the exfoliated state is much more actively involved in the crystallization. As far as mechanical properties are concerned, the exfoliated structure would give us more enhanced properties than the intercalated one. 

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Figure 20.8 Mechanical properties of SPS nanocomposites prepared by direct melt intercalation method (a) tensile strength, (b) tensile modulus, and (c) flexural modulus. Reprinted with permission from Reference 15. Copyright Wiley-VCH Verlag GmbH Co. KGaA.

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