Carbonate categories, fillers

Carbon nanotube fillers include three main categories single-wall, multiwall, and double-wall. Figure 19.1 shows transmission electron microscope (TEM) images of each category. 

This work laid the foundation for many of the newer technology carbon blacks. These fall into two categories postprocess modification, where the surface of the carbon black is treated to improve its properties and in-process modification, where another material is introduced to again enhance the basic properties of the filler (Wampler et ah, 2004). 

Nanofillers may be nanoclays, carbon nanotubes (single or multiwall) (CNTs), silica, layered double hydroxides (LDHs), metal oxides, etc., offering the promise of a variety of new composites, adhesives, coatings, and sealant materials with specific properties [32-37]. Among the fillers mentioned, nanoclays have attracted most of the academia and industry interest, due to their abrmdance as raw materials and to the fact that their dispersion in polymer matrices has been studied for decades [38]. In fact, there are three major polymer nanocomposites categories in terms of nanofiller type that are expected to compile the global nanocomposites market in 2011 nanoclay-reinforced (24%), metal oxide-reinforced (19%), and CNTs-reinforced (15%) ones [39-41]. 

An extremely important factor not implicitly obvious in the two examples described previously is the specificity of the surface chemistry to each composite system. Of course many surface reactive agents can be used in more than one system, and MPS and stearic acid fall into this category. However, the MPS and stearic acid could not be interchanged between the two examples, not only due to the mono functionality of the stearic acid, but due to the relative lack of reactivity between silanes and calcium carbonate, and stearic acid and silica. In the latter case, the hydroxyl groups, which are formed at the silica crystal surfaces to satisfy valency demands, are acidic in nature and hence do not form strong bonds with the carboxylic acid group. If the silica was substituted, for example, with alumina then the stearic acid would interact with the surface of the filler, as the hydroxyls formed at crystal discontinuities in alumina are basic in character. 

Besides the API, excipients such as a filler or fillers, a disintegrant (not applicable to controlled release), and a binder are also included in the powder mixture of a tablet formulation. The fillers used in tablet formulations can be classified into two categories, based on their water solubility soluble fillers such as lactose, sucrose, mannitol, etc., and insoluble fillers such as MCC, starch, calcium carbonate, calcium phosphate, etc. The binders used in the wet granulation process are water-soluble... 

Static dissipative materials are an intermediate category, used where there is a need for sm face resistivities in the range 10 -10 ohm/square. These values can be achieved using carbon black or similar fillers. They are relevant to products where static build-up causes arcing or short circuits. 

Applications of Raman to polymer/additive deformulation are still rather few, especially if compared to IR methods (cfr. Chp. 1.2.1). Hummel [108] has attributed the general lack of applications of RS in the field of plastics additives to poor Raman scattering of certain substance categories, unsatisfactory reproducibility of the spectra and scarcity of specific Raman libraries [385,386]. Polymer/additive analysis by means of Raman spectroscopy is mainly restricted to fillers, pigments and dyes the major usefulness comes from NIR FT-Raman, which greatly overcomes the fluorescence problem. The ion-pair dissociation effect of the 2-keto-4-(2,5,8,11-tetraoxadodecyl)-l,3-dioxolane modified carbonate (MC3) plasticiser in poly(ethylene oxide) (PEO) was studied by means of Raman, FTIR and EX-AFS [387]. Another study established the feasibility of using Raman spectroscopy to quantify levels of melamine and melamine cyanurate in nylons [388]. 

Wood plastic composites (WPCs), which are produced from wood flour and TP, are used widely as industrial material in the fleld of biocomposites. WPC is included under the category of the filler for filling plastic material, which includes inorganic materials, such as sihca, talc, and calcium carbonate. Therefore, its method of production is also based on the method used for fillers for filling plastic, divided into the compounding process that makes molten mixture of wood flour as filler and... 

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