Polymer/layered inorganic

A classification of methods for preparing polymer-layered inorganic solid compounds takes into account the main processes involved in the synthesis of the final hybrid material. The nature of both the 2D host solid and the guest polyma- determines the pathway applicable to obtain a particular nanocomposite and, in certain cases, is decisive in the behavior of the resulting material. In... 

As for the thermodynamic consideration in Section 2.2.1, we attempt to highlight these challenges by describing in some detail the most common synthetic routes for nanocomposite formation employed for polymer/layered-inorganic hybrids. Most examples are drawn from layered-silicate fillers, but the conclusions are general across most nanofillers, and one should be able to envision similar strategies for nanocomposite formation based on other types of nanofillers. 

Due to its ease of use and availability, simple Bragg-refiection powder x-ray diffraction is most commonly used to probe nanocomposite structure, especially for polymer/layered-inorganic filler hybrids where the [Pg.42]

Some examples of the application of eq. (2.6) for polymer/layered-inorganic nanocomposites could be ... 

It has been well documented that polymer/layered-inorganic and polymer/clay nanocomposites are being explored extensively due to their high promise for potential applications and as model systems for nanoscopically confined polymers. These polymer/inorganic nanocomposites can be prepared by... 

In thick samples, a boron oxide/boron carbide crust has been detected on the surface of the polymer. This inorganic surface layer has a shielding effect on the inner polymer layers, further enhancing the thermal stability of the material. Poly(m-carborane-siloxane)s have therefore been considered as surface coatings for organic materials, providing protection from erosion effects. 

The use of UV-polymerized, vacuum-deposifed film has enabled fhe development of mulhlayer barrier coatings for thin-film phofovolfaics and flexible electronics. The patented system uses thin polymer layers that are deposited alternatively with thin barrier layers. The mulhlayer structure is composed from organic (polymer) and inorganic (oxide) layers. 

An attractive route to creating stable multilayers is electrostatic self-assembly using polyelectrolytes. Since the interaction between the polymer layer and the substrate, or between alternating layers, is based on electrostatic interactions, the chemical nature of the electrostatic components can be varied systematically. As a result, there is an extensive literature based on, among others, polymer-polymer, polymer-organic, polymer-inorganic, and polymer-biomolecular assemblies. 

Figures 15.8 and 15.9 illustrate examples of how cone calorimeter data can be used in the development of flame-retarded materials. PA 66-GF without Pred showed typical fire behavior for noncharring polymers containing inorganic glass fiber as inert filler,69 when high external heat flux is applied. The shape of the HRR curve is divided in two different parts. In the beginning, the surface layer pyrolysis shows a sharp peak, followed by a reduced pyrolysis rate when the pyrolysis zone is covered by the glass fiber network residue layer. When Pred was added, the PA 66-GF samples were transformed into carbonaceous char-forming materials, which led to a...

As outlined in the introduction, polymer melts can intercalate layered inorganic compounds unassisted by shear or solvents. This is a rather surprising result as it implies that polymer chains can undergo large center of mass displacement in almost two dimensional interstices as the distances between the confining sur-... 

Rheology of various polymer layered-silicate nanocomposites - intercalated, exfoliated and end-tethered exfoliated (prepared by in-situ polymerization from reactive groups tethered to the silicate surface), have been performed in a conventional melt-state rheometer in both oscillatory and steady shear modes. These experimental studies have provided insight into the relaxation of polymer chains when confined by the layers of inorganic silicates, as well as the role of shear in orienting the layered nanocomposites. 

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