Organic chemical accelerators

Organic chemical accelerators were not used until 1906, 65 years after the Goodyear-Hancook development of unaccelerated vulcanization (Figure 14.1), when the effect of aniline on sulfur vulcanization was discovered by Oenslayer [3]. 

A substance can be classified chemically in many ways. One of the simplest ways to classify a substance is as an element or a compound. An element is a pure substance that cannot be changed into a simpler substance by chemical means. Elements are the building blocks of nature all matter is composed of elements. The periodic table is a concise map that organizes chemical elements into columns (groups) and rows (periods) based on their chemical properties. Currently, there are 118 known chemical elements, with whole numbers 1 to 118. These numbers are referred to as the element s atomic number and give the number of protons in the nucleus of an atom of the element. For example, carbon s atomic number is 6 and each carbon atom has 6 protons in its nucleus. The first 92 elements occur naturally, and those above atomic number 92 are synthesized through nuclear reactions using particle accelerators. Element 118 was just confirmed in the fall of 2006, and by now, more elements may have been produced. 

It should be stressed that the majority of literature reports on the acceleration of chemical reactions by microwave irradiation (even more than 1000 fold) come from the initial period of the application of microwaves in organic synthesis (i.e. from late 1980 s and early 1980 s). At this time there were no dedicated microwave scientific reactors available on the market, and most of theses reactions were conducted in household microwave ovens. Recently, applying modern microwave reactors, scientists have verified a number of these reports, and it turns out that the claimed acceleration of the majority chemical reactions were attributed to difficulties with proper temperature measuments rather than to non-thermal micowave effects. Sometimes it was found that these effects were results of faster delivering of energy to the reaction systems [35,38]. 

Curatives. The function of curatives is to cross-link the polymer chains into a network the most common ones are the sulfur type for unsaturated rubber and peroxides for saturated polymers. Chemicals called accelerators may be added to control the cure rate in the sulfur system these materials generally are complex organic chemicals containing sulfur and nitrogen... 

The use of well-designed chemical processes, aided hy chiral molecular catalysts, can provide truly practical and efficient synthetic methods for the production of hioactive substances and functional materials. In particular, the growing awareness of the importance of chirality to the function of chemical substances has led to the development of many new chiral molecular catalysts for use in large-scale production. Chiral molecular catalysts consisting of a metal atom or ion and a chiral organic ligand(s), under the appropriate conditions, can not only repeatedly accelerate organic reactions, but also simultaneously control the absolute stereochemical outcome [1]. 

Use Ammonium salts, medicine (expectorant), baking powders, smelling-salts, fire-extinguishing compounds, pharmaceuticals, textiles (mordant), fermentation accelerator in wine manufacture, organic chemicals, ceramics, washing wool. 

Use Substitute for acetaldehyde rubber accelerators rubber antioxidants synthetic organic chemicals dyestuff intermediates solvent for fats, oils, waxes, gums, resins leather solvent mixture for cellulose derivatives sedative (hypnotic). 

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