Polymer-clay composites

Micro-composites are formed when the polymer chain is unable to intercalate into the silicate layer and therefore phase separated polymer/clay composites are formed. Their properties remain the same as the conventional micro-composites as shown in Figure 2(a). Intercalated nano-composite is obtained when the polymer chain is inserted between clay layers such that the interlayer spacing is expanded, but the layers still bear a well-defined spatial relationship to each other as shown in Figure 2(b). Exfoliated nano-composites are formed when the layers of the day have been completely separated and the individual layers are distributed throughout the organic matrix as shown in Figure 2(c). 

FIG. 2 Schematic illustration of three types of polymer-clay composites. 

There have been a number of studies of polymers at surfaces, as illustrated in Figure 8, including some that have been tethered [10, 122-137]. Also in this category are the polymer-clay composites after the previously paired platelets have been sufficiently separated to be independent of one another. Such exfoliated arrangements are shown in Figure 9. 

V. V. Ginzburg and A. C. Balazs, Calculating phase diagrams of polymer-platelet mixtures using density functional theory Implications for polymer/clay composites, Macromolecules 32, 5681-5688 (1999). 

B.N. Jang, M. Costache, and C.A. Wilkie, The relationship between thermal degradation behaviour of polymer and the fire retardancy of polymer/clay composites, Polymer, 2005, 46 10678-10687. 

Constants A l7 A0, and Ai are determined by the choice of the lattice in our calculations, A i =Ai =0.25 and A0 = 0.5. This choice corresponds to the simple cubic lattice, which is commonly used in the application of lattice SCFT to polymer-clay composites. To relate the lattice coordinate to "real" dimensions, we must also specify the value of the lattice size a here, we set a = 0.4 nm. (Later, in Section 3.5, when describing our results, we will automatically convert all distances from lattice units to nanometers.)... 

Ginzburg, V. V., Singh, C., and Balazs, A. C., Theoretical phase diagrams of polymer/clay composites the role of grafted organic modifiers. Macromolecules, 33, 1089-1099 (2000). 

Besides properties (which are usually enhanced by adding clay), another crucial factor of PCN materials elaborated through emulsion polymerization is their solid content. Although this point is less frequently addressed, most of the polymer/clay composite latexes reported in literature have solid contents below 20%. However, solid contents between 40% and 60% and sometimes higher are required for industrial applications. Using a seeded semi-batch emulsion polymerization process and a procedure otherwise very similar to that described above for Bentonite,... 

Belgian cable company Kabelwerk Eupen has introduced a commercial application for polymer-clay composites to make flame retardant cables. EVA-based cable jackets are combined with the clay materials in what is called a one-pot synthesis extrusion technique. 5% of the nanoclay improves the fire performance of the EVA compound by promoting char formation and delaying degradation. In addition, it prevents dripping of any burning polymer material. 

H. Mae, Dynamic tensile behavior and light transmittance of cyclo-olefine polymer/clay composites, Zairyo/Joumal of the Society of Materials Science, Japan 58 (11) (2009) 895-902. 

S. D.B. (1997) Box-Behnken design applied to smdy the strengthening of aluminate concrete modified by a superabsorbent polymer/clay composite. Adv. Cement Res., 9 (35), 93-97. 

Balazs and co-workers (85,86) have modeled the phase behavior of polymer-clay composites. They assumed the individual clay sheets were rigid disks of diameter Z>, and thickness L.The assumption of disks (see Rgure 13.9) rather than rectangular plates simplifies the mathematics without losing essential features. 

Polymer-clay composites can be divided into three categories ... 

Fig. 3 Schematic illustration the morphologies of polymer/clay composites...

Figure 16.24. Three possible types of polymer/clay composites. [Adapted, by permission, from Lan T, Kaviratna P D, Pinnavaia T J, Chem. of Mat., 1, No.l 1, 1995,2144-50.]...

Stempfle B, GroBe A, Ferse B, Arndt K-F, W611D (2014) Anomalous diffusion in thermore-sponsive polymer-clay composite hydrogels prohed by widefield fluorescence microscopy. Langmuir. doi 10.1021/la503571j... 

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