Applications of nanoclays

AAffien the strong covalency, present among the aromatic sheets of graphite stiucttue, is utilized, carbon fibers could show more efficiency than transitional ones. Though theoretically it has been proved, in practice, these sheets are lacking in strength due to lack of interconnection between the aromatic sheets [22]. 

If the same reason is applied to layered filler composite materials, they show very high strength. The clay composite with 4 wt% clay loading 

RrMl dovyrf nf the agglomerates hv means of shear stress (t) 

Kneaded polymer melt (Matrix phase) Mixing section of kneader 

1st STEP modified clay widi an organic ammmium 

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On the basis of PF resin, PUF resin has been developed to decrease the cost and to accelerate curing. Similar to the standard PF resin, PUF resin is prepared under alkaline conditions. Application of nanoclays to urea-formaldehyde (UF) resins has recently shown that nanoclays can improve the properties of thermosetting resins for interior-grade wood adhesives [20], and urea in PF resin could possibly be useful for the preparation of PUF resin/MMT composites, too. 

Figure 6.4 A schematic representation of various applications of nanoclays in nanoclay industries [14].

The first commercial application of nanoclay polymer nanocomposites was a timing-belt cover made of polyamide nanocomposite by Toyota Motors in the 90s. Since then, CPN grabbed great attention and the research about their properties and applications experienced a vast boost. 

Nanocomposites General Motors and Basell Polyolefins continue the development of nanocomposites for high-volume applications in external trim parts such as body panels. Three grades of TPO-based nanocomposites reinforced with 2.5% nanoclay have been commercialized by Basell Polyolefins. The first application of these nanocomposites was a low-volume minivan step option. 

J-M Thomasin, Ch Pagnoulle, G Caldarella, A Germain and R Jerome, Contribution of nanoclays to the barrier properties of a model proton exchange membrane for fuell cell application. Journal of Membrane Science, Vol. 270 (2006) p.50... 

In combination with nanoclays, nanocomposites can be produced for a wide field of applications. Even low loadings of nanoclays with high aspect ratios to biopol5miers can have a profoimd enhancing effect over the material properties (42). Such nanocomposites have an improved strength and stiffness, a low gas vapor permeability, a low coefficient of thermal expansion, and an increased heat deflection temperature. However, in this field also some technical difficulties emerge, but these can be circumvented (40). 

The in situ synthesis of polymers in the presence of nanoclays can produce good nanofiller dispersions but is often difficult to control and its production times are relatively long. Melt processing is certainly the most interesting preparation method from an application and economical point of view since it can be readily implemented into traditional polymer processing routes and provide reliable and reproducible products. 

Besides mechanical performance, the introduction of nanoclay to the proper location and with the proper phase morphology can also be utilized to enhance the permeation properties of polymer blends in barrier film applications. The high aspect ratio and platelike shape of impermeable montmorillonite inclusions allow them to disrupt the diffusion of permeants through a polymer, thereby increasing the tortuosity of the path through the film and reducing its permeability. The component polymers comprising blends are often selected for reasons other than... 

Use of nanoparticles as fillers in mbbers is highly relevant because end use applications of rubber compounds require filler reinforcement. Most of the literature on rubber nanocomposites is based on the use of nanoclay as the filler. It has been shown that incorporation of nanoclay in synthetic rubbers, like styrene butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), ethylene propylene diene monomer (EPDM) mbber etc. enhances the mechanical, anti-ageing and barrier properties. 

Polylactides (PLA) may have many potential applications for an important set of products but some of their properties should be improved to obtain similar performance to petroleum-based commodities. One of the most important current applications of PLA is food packaging, in particular for short-shelf-life products with common applications such as rigid containers, drinking cups, over-wrap and lamination films. PLA production and consumption are expected to increase therefore research into the variation of PLA mechanical and barrier properties is currently very active. The control of barrier properties in PLA films is possible by modification of the polymer network through the formation of intramolecular and inter-molecular covalent crosslinking, for example by applying thermal treatment, or by modifying the chemical composition. Another method is to incorporate fillers, in particular layered nanoclays, and this will be the subject of this chapter. 

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