Functional fillers affecting

Encapsulation of different entities inside the CNT channel stands alone as an alternative noncovalent functionalization approach. Many studies on the filling of carbon nanotubes with ions or molecules focus on how the presence of these fillers affects the physical properties of the tubes. From a different point of view, confinement of materials inside the cylindrical structure could be regarded as a way to protect such materials from the external environment, with the tubes acting as a nanoreactor or a nanotransporter. It is fascinating to envision specific reactions between molecules occurring inside the aromatic cylindrical framework, tailored by CNT characteristic parameters such as diameter, affinity towards specific molecules, etc. 

One function of a coupling agent is to interact with filler. It is thus proven a priori that coupling agents affect filler properties, and modified fillers affect the system. Numerous works use this modification. In this discussion, we summarize the effects obtained. Table 13.1 contains this summary. 

Wood makes an excellent functional filler, but within limits. While the heat used to melt and process plastics does not affect mineral-based fillers, it does affect wood. Therefore, great care must be exercised when using wood as a functional filler. Moreover, wood absorbs moisture, while thermoplastic processing equipment has a near-zero tolerance for moisture. 

Parameters affecting the performance of polymer composites containing functional fillers are related to... 

Part I, entitled Polymers and Fillers, contains a general introduction to polymer composites, a review of the parameters affecting mechanical and rheological properties of polymers containing functional fillers and an overview of mixing and compounding equipment along with methods of filler incorporation in molten and liquid polymers. 

Permanent Set. When an elastomer is stretched and then allowed to relax, it will not completely recover its original dimensions. This divergence from its original form is called its permanent set. It is principally affected by the affinity of the elastomer for the filler surface and is, therefore, primarily a function of the surface energy or wetting of the filler. 

The dynamic mechanical behavior of most homogeneous and heterogeneous solid and molten polymeric systems or composite formulations can be determined by DMA. These polymeric systems may contain chemical additives, including fillers, reinforcements, stabilizers, plasticizers, flame retardants, impact modifiers, processing aids, and other chemical additives, which are added to the polymeric system to impart specific functional properties and which could affect the process-ability and performance. 

Certain types of fillers, even though unreactive, will affect the pot life and exotherm of the adhesive system. Generally, modifications of cure or reactivity are not the prime functions of... 

Compression set is an important property of elastomers which is affected by the choice of filler. Studies were conducted on silica in silicon rubber vulcanizates. Figure 8.60 shows the relationship between the surface area of silica and compression set. As the surface area increases compression set increases. The increase surface area contributes to an increase in the number of functional groups on the surface of silica. These groups can potentially react with siloxane. When they do, there is a good interaction of filler with matrix which contributes to reduction of compression set (Figure 8.61). ... 

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