Accelerators inorganic

Butyraldehyde-aniline condensation product Lead dimethyidithiocarbamate accelerator, inorganic rubber Magnesium oxide accelerator, IR... 

Surfactants have also been of interest for their ability to support reactions in normally inhospitable environments. Reactions such as hydrolysis, aminolysis, solvolysis, and, in inorganic chemistry, of aquation of complex ions, may be retarded, accelerated, or differently sensitive to catalysts relative to the behavior in ordinary solutions (see Refs. 205 and 206 for reviews). The acid-base chemistry in micellar solutions has been investigated by Drummond and co-workers [207]. A useful model has been the pseudophase model [206-209] in which reactants are either in solution or solubilized in micelles and partition between the two as though two distinct phases were involved. In inverse micelles in nonpolar media, water is concentrated in the micellar core and reactions in the micelle may be greatly accelerated [206, 210]. The confining environment of a solubilized reactant may lead to stereochemical consequences as in photodimerization reactions in micelles [211] or vesicles [212] or in the generation of radical pairs [213]. 

Enzyme action is frequently accelerated or retarded by the presence of other substances both organic and inorganic. Such substances have been divided into three categories (a) co-enzymes, without which certain enzymes are unable to function (i) activators, and (c) inhibitors. 

Surface heterogeneity is difficult to remove from crystalline inorganic substances, such as metal oxides, without causing large loss of surface areas by sintering. Thus in Fig. 2.14 in which the adsorbent was rutile (TiO ) all three adsorbates show a continuous diminution in the heat of adsorption as the surface coverage increases, but with an accelerated rate of fall as monolayer completion is approached. 

Whereas decomposition is slow in pure solutions, it is accelerated enormously by alkali and traces of many metal ions. Indeed, hydrolysis to H2O2, followed by its disproportionation, is the main path for decomposition of inorganic peroxides. 

Retarders and Accelerators. Materials that control hardening of cement may be either organic or inorganic. Retarders are often incorporated in oil well cementing and hot-weather concrete appHcations, whereas accelerators may be useful for cold-weather concrete appHcations in which higher rates of reactivity are desirable. In most cases, these admixtures are used in low concentrations, suggesting that they act by adsorption. 

Acid producers. Many bacteria produce acids. Acids may be organic or inorganic depending on the specific bacterium. In either case, the acids produced lower the pH, usually accelerating attack. Although many kinds of bacteria may generate acids, Thiobacillus thiooxidans and Clostridium species have most often been linked to accelerated corrosion on steel. 

Perhaps the lowest cost accelerators for PF resoles are inorganic carbonates and carbon dioxide [118,183,184], Potash and soda ash have been added to PF plywood mixes for many years. Though the results are not as dramatic as those seen with organic esters, resorcinol, and related derivatives, they work well and are cost effective. The mechanism by which they operate is not known. Levels between 0.25 and 2%, based on liquid resin are normally used. 

Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials Avoid contamination with combustible materials, various inorganic and organic acids, alkalies, alcohols, amines, easily oxidizable materials such as ethers, or materials used as accelerators in polymerizations reactions Stability During Transport Extremely explosion-sensitive to shock, heat and friction. Self-reactive Neutralizing Agents for Acids and Caustics Not pertinent Polymerization Not pertinent inhibitor of Polymerization Not pertinent. 

Ionic liquids hold as much promise for inorganic and organometallic synthesis as they do for organic synthesis. Their lade of vapor pressure has already been exploited [13], as have their interesting solubility properties. The field can only be expected to accelerate from its slow beginnings. 

Bis(tributyltin) oxide is known to break down to inorganic tin under UV irradiation in laboratory conditions (509, 510), and the decomposition may be accelerated by absorbing the organotin compound on a cel-lulosic matrix (511). As bis(tributyltin) oxide is known to react rapidly with carbon dioxide (atmospheric, or trapped in various cellulosic materials, such as cotton or wood) (512), to form bis(tributyltin) carbonate, (BusSnO)2CO, the observed UV degradation pattern may be rationalized in terms of more-ready breakdown of the carbonate than of the oxide, due to the presence of the carbonyl chromophore. The half-life of bis(tributyltin) oxide in pond water has recently been given as 16 days (513). Diorganotin compounds have also been shown to decompose to inorganic tin under UV irradiation (514, 515). 

This technique relies on the formation of ions hy various means in a high-vacuum chamber, their acceleration hy an electrical field and subsequent separation hy mass/charge ratio in a magnetic field and the detection of each species. It can he used for both inorganic and organic substances, be very sensitive, and be of value in examining mixtures of compounds especially if linked to glc. Usually this is a laboratory technique but portable or transportable models are now available. ... 

In our previous publication [4] we demonstrated that the ammonium salts of different organic and inorganic acids influence the reactions which are performed at the interaction of pectin with ammonia, as they accelerate the ammonolysis and retard the hydrolysis and degradation of the pectin macromolecules. 

A mechanism proposed 87) for the alkaline hydrolysis of tetraethyl pyrophosphate, which is markedly accelerated by HPO e ions, has been substantiated by isotopic labeling 88). The nucleophilic attack by HPOJp on the symmetrical pyrophosphate 131 is considered to lead initially to the unsymmetrical P P1-diethyl pyrophosphate dianion 132 which decomposes spontaneously under the conditions of reaction to give the diethyl phosphate anion and POf 102. The latter reacts with water to form inorganic phosphate and with alcohols suclj as methanol and ethylene glycol to produce alkyl phosphates. 

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