Fillers, morphological and

It has been well established that wear resistance of filled rubber is essentially determined by filler loading, filler morphology, and polymer-filler interaction. For fillers having similar morphologies, an increase in polymer-filler interaction, either through enhancement of physical adsorption of polymer chains on the filler surface, or via creation of chemical linkages between filler and polymer, is crucial to the enhancement of wear resistance. In addition, filler dispersion is also essential as it is directly related to the contact area of polymer with filler, hence polymer-filler interaction. 

Vovchenko, L.L., Matzui, L.Y., Oliynyk, V.V., Launetz, Vi., 2011. The effect of filler morphology and distribution on electrical and shielding properties of graphite-epoxy composites. Molecular Crystals and Liquid Crystals 535, 179—188. 

Particle Morphology, Size, and Distribution. Many fillers have morphological and optical characteristics that allow these materials to be identified microscopically with great accuracy, even in a single particle. Photomicrographs, descriptions, and other aids to particle identification can be found (1). 

Polymers with differing morphologies respond differentiy to fillers (qv) and reinforcements. In crystalline resins, heat distortion temperature (HDT) increases as the aspect ratio and amount of filler and reinforcement are increased. In fact, glass reinforcement can result in the HDT approaching the melting point. Amorphous polymers are much less affected. Addition of fillers, however, intermpts amorphous polymer molecules physical interactions, and certain properties, such as impact strength, are reduced. 

Since most polymers, including elastomers, are immiscible with each other, their blends undergo phase separation with poor adhesion between the matrix and dispersed phase. The properties of such blends are often poorer than the individual components. At the same time, it is often desired to combine the process and performance characteristics of two or more polymers, to develop industrially useful products. This is accomplished by compatibilizing the blend, either by adding a third component, called compatibilizer, or by chemically or mechanically enhancing the interaction of the two-component polymers. The ultimate objective is to develop a morphology that will allow smooth stress transfer from one phase to the other and allow the product to resist failure under multiple stresses. In case of elastomer blends, compatibilization is especially useful to aid uniform distribution of fillers, curatives, and plasticizers to obtain a morphologically and mechanically sound product. Compatibilization of elastomeric blends is accomplished in two ways, mechanically and chemically. 

Visualization of Nano-Filler Dispersion and Morphology in Rubbery Matrix by 3D-TEM... 

Recent demands for polymeric materials request them to be multifunctional and high performance. Therefore, the research and development of composite materials have become more important because single-polymeric materials can never satisfy such requests. Especially, nanocomposite materials where nanoscale fillers are incorporated with polymeric materials draw much more attention, which accelerates the development of evaluation techniques that have nanometer-scale resolution." To date, transmission electron microscopy (TEM) has been widely used for this purpose, while the technique never catches mechanical information of such materials in general. The realization of much-higher-performance materials requires the evaluation technique that enables us to investigate morphological and mechanical properties at the same time. AFM must be an appropriate candidate because it has almost comparable resolution with TEM. Furthermore, mechanical properties can be readily obtained by AFM due to the fact that the sharp probe tip attached to soft cantilever directly touches the surface of materials in question. Therefore, many of polymer researchers have started to use this novel technique." In this section, we introduce the results using the method described in Section 21.3.3 on CB-reinforced NR. 

Researchers [37] also compared the storage modulus of a 40 phr carbon black-filled compound and a 10 phr SWNT-NR nanocomposite. The different properties between carbon black- and SWNTs-filled NR nanocomposites can be explained in terms of two different filler morphology, particularly surface area, aspect ratio, and stmcture. It can be observed from Figure 28.22 that... 

See, J.L. Leblanc, Insight into elastomer—filler interactions and their role in the processing behaviour of mbber compounds, Prog. Rubber Plast. TechnoL, 10/2, 110-129, 1994, for a pictorial representation of such a morphology. 

Journal of Applied Polymer Science 83, No.2, 10th Jan.2002, p.357-66 MORPHOLOGY AND PHYSICAL PROPERTIES OF CLOSED CELL MICROCELLULAR ETHYLENE-OCTENE COPOLYMER EFFECT OF PRECIPITATED SILICA FILLER AND BLOWING AGENT Nayak N C Tripathy D K Indian Institute of Technology... 

Two points have to be stressed before considering the measurement of morphology. The first point to make in discussing filler morphology is that, except for rare instances such as monomodal glass spheres, the morphology of filler particles is complex and they will have a distribution of shapes and sizes which cannot be expressed as a single parameter. 

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