Rheology of Blends with Nanoparticles

Compatibilization of polymer blends aims to improve the interaction between phases, ascertaining the appropriate, stable morphology and improved performance. Blends have been compatibilized mainly by addition of a compatibilizer, a co-solvent, or in a reactive process, where the compatibilizing molecules are formed within the interphase [1, 73, 302]. About 20 years ago a note in a USSR technological journal reported that the addition of a small amount of PMMA to a PE/PS blend reduced the PS drop diameter by a factor of ten. The effect was later explained by a balance of the three interfacial tension coefficients in the blends, inter-related by Neuman s triangle equation [1,352,353]. In simple terms, the PMMA, immiscible in PE and PS, formed a layer around PS drops, preventing coalescence. In a sense, addition of nanoparticles to polymer blends acts similarly. 

Polymer blends have been used as matrices of polymeric nanocomposites (PNGs) or more precisely clay-containing polymeric nanocomposites (CPNCs) since the early 1990s [64]. The clay platelets migrate to the interphase, strengthen and rigidify it. 

Fenouillot et ol. [368] reviewed polymer blends with solid nanopartides. The authors briefly discussed oil/water emulsions with solid colloidal partides, considering their wettability and location. Next, polymer blends with nanopartides were discussed, starting with systems near the phase separation, and then within the immiscibility region. Some similarities and differences between the low- and high-viscosity emulsions were highlighted. The particular reason for preparing the review seems to be the authors search for factors that may affect nanoparticle localization at the thermodynamic equilibrium. Diverse polymer blends with pseudo-spherical 

1) Nanopartides are surface active, adsorbing macromolecules and reducing their mobility. 

2) For minimization of the system s free energy the thermodynamics adjusts the interphase compositions as a function of interactions. 

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Rheology of Blends with Nanoparticles Near Binodal... 

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