Inorganic additives types

A large number of materials, generally inorganic in nature, have been used as additive-type flame retardants, of which hydrated alumina and antimony oxide are among the most important. 

Figure 3. Effect of inorganic additives on the density of the smoke evolved from brominated polyester resin in the NBS-type Smoke Chamber.

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This non-destructive technique is a very suitable tool for rapid in-line analysis of inorganic additives in food products (Price and Major, 1990 Anon, 1995). It can be readily used by non-skilled operators, and dry materials can be pressed into a pellet or simply poured into a sample cup. The principles of this technique related to food analysis are described by Pomeranz and Meloan (1994). A useful Internet site is http //www.xraysite.com, which includes information about different XRF instruments from various companies. Wavelength dispersive X-ray fluorescence (WD-XRF) or bench-top energy dispersive (ED-XRF) instruments are available. XRF is a comparative technique, thus a calibration curve needs to be established using food products of the same type as those to be... 

The effect of amending soil with other types of organic-rich material has also been investigated by sequential extraction. These materials include chicken manure and cowpea leaves (Li et al, 1997) spent mushroom compost, commercial humic acid and poultry litter (Shuman, 1998) and cow manure, pig manure and peat soil (Narwal and Singh, 1998). The mechanisms by which inorganic additives (zeolite, apatite and iron oxide) reduce uptake of Cd and Pb by crops have also been studied (Chlopecka and Adriano, 1997). 

Analysis of the nny 82 ammunition as previously detailed shows that it uses a mercuric corrosive primer. Analysis of the Chinese 351/73 ammunition revealed that it has a copper-coated iron-jacketed bullet with an iron core and a lead tip, the cartridge case is steel with a brown colored lacquered finish, a brass primer cup, and the propellant is single based with DPA, 2 x nitrodiphenylamines, camphor, and contains no inorganic additives, and the discharged primer composition is antimony, potassium, chlorine, mercury, tin, sulfur, iron, manganese, phosphorus, zinc, and lead in descending order (lead, antimony, mercury type). 

Py-GC/MS can be applied for both qualitative and quantitative purposes. One typical use of quantitative analysis using pyrolysis is the determination of the amount of a specific polymer in a given complex matrix, such as a composite material, inorganic matrix, etc. Since solubilization is frequently a very difficult task for these materials, pyrolysis can provide quantitative information based on the level of the polymer marker generated by the thermal decomposition. Calibration is typically necessary in these situations, and similarly to other analytical procedures this can be achieved using a standard addition type procedure (see e.g. [17]) or a calibration with known amounts of polymer in a similar or identical matrix. Another case where the quantitation can be necessary is the determination of the amount of a comonomer in a copolymer sample. Successful quantitation by Py-GC/MS is reported in literature for various copolymers [25-39], etc. 

Inorganic additives for rubber compounds also include materials that enhance performance under various accelerated stress conditions. Zinc oxide is an effective heat stabilizer for some types of elastomers. Iron oxide, lead compounds, barium salts, and specially treated clays, such as kaolinite, add performance margin in wet aging conditions. 

The preparation of composites prepared by high temperature decomposition reactions have mainly concentrated on polyimides and reactive inorganic additives (e.g., simple salts and complexes). In many cases polymer-metal composites have been unintentionally produced by workers whose primary goal was the modification of polyimide properties by incorporation of metal ions. For example, approximately 30 years ago Angelo briefly reported in a patent the addition of metal ions to several types of polyimides for the purpose of forming particle-containing transparent polyimide shaped structures. Ten years... 

Protection against ignitability can be increased by different techniques such as inorganic additives (magnesium hydroxide and magnesium oxide). Reducing smoke is also an important requirement for the modern society which can be achieved by different types of additives. 

The primary drawbacks of the Nafion membranes are poor conductivity at low relative humidities (and consequently at temperatures >100 C and ambient pressure) and large crossover of methanol in direct methanol fuel ceU (DMFC) applications. As a result, considerable efforts have been made in recent years to overcome these drawbacks. Peihaps the most widely employed approach is the addition of inorganic additives to Nafion m branes to yield organic/inorganic composite membranes. Three major types of inorganic additives that have been studied (zirconium phosphates, heteropolyadds, metal hydrogen sulfates and metal oxides) are reviewed in the following. 

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