Base retardation

Substance TBBA replaces PBB/PBDE Polymerized TBBA Phosphorus-based retardants Mineral-based retardants Change base material Separate high and low voltage Reduce voltage... 

This material is a quaternary base retarding material found to be extremely effective and efficient in the dyeing of acrylic fibers, and is substantive in nature. 

Since hydroalumination by neutral aluminum hydrides is an electrophilic attack on a C= or C=C linkage, the reaction can be accelerated by Lewis acids such as aluminum halides, and be retarded by Lewis bases like R3N, R2O or even unsaturated R3AI cf. equation 38). Such reagents also exert an effect on the syn or anti character of the A1—H adduct. Evidence suggests that Lewis acids or bases principally affect the rate of isomerization of the initial syn adduct into the generally more stable anti adduct Lewis bases retard such isomerizations, while Lewis acids promote them. The presence of ethers or tertiary amines stabilize the syn adducts of alkynyl-silanes and -germanes (47) and permit such adducts to be formed in >95% geometrical purity (Scheme 12). ... 

Fires involving materials treated with anti-ChEs or bulk pesticides stores (CM and OP) may release both the unaltered anti-ChE and thermal decomposition products. Also, certain phosphorus-based fire retardants that arc subjected to heat and flame in a fire may result in the generation of anti-ChEs and other toxic materials. Thus, although fire retardants may slow the rate of fire progression, their involvement in a conflagration may result in an increase in the toxic potency of combustion products (Purser, 1992). For example, polyurethane foams treated with a trimethylol propane polyol base containing phosphoms-based retardants formed a highly neurotoxic combustion product [irimethylolpropane phosphate (TMPP) Petajan et at., 19751. 

ACID RETARDATION," "BASE RETARDATION," AND "SALT RETARDATION" PHENOMENA... 

The above-discussed acid retardation and base retardation in the immobiUzed Uquid phase could be compared with the so-called salting-out effects. However, this term is hardly applicable to the case of salt retardation, the first example of which was demonstrated by a successful removal of small amounts of NH4CI from a concentrated brine of (NH4)2S04. This practically important problem arises in the manufacture of caprolactam, where large amounts of sulfuric acid are converted into ammonium sulfate used for the preparation of the crystalline fertilizer. The new process of ISE on nanoporous NN-381 resin allowed an effective purification of very large volumes of concentrated sulfate brine, due to the fact that small ions of NH and Cl are efficiently squeezed into and retained in the finest pores of the sorbent [172]. We consider this salt retardation process as a convincing proof of our interpretation of the mechanisms of the new electrolyte separation process. 

Acid retardation base retardation, and salt retardation phenomena 475... 

Phosphorus-based retardants possess the second largest market [1] and comprise a large number of forms associated with different mechanisms. Among these, a basic mechanism is achieved through the reactions between chemicals produced... 

The plastics industry claims that there is no scientific evidence to support the belief that dangerous compounds can be released on incineration and the safety of bromine-based retardants has been confirmed by bodies such as the US Environmental Protection Agency, the United Nations, the World Health Organization, and the Organization for Economic Cooperation and Development. Nevertheless, some compounds have been withdrawn. 

With special synergists, a protective coating in the form of an intumescent layer can be formed in case of flaming, and phosphorus FRs are also good suppressors of afterglow and smoke. These properties make phosphorus-based retardants of particular interest in gel coats. 

Fillers may promote char magnesium hydroxide, zinc borate, antimony oxides require high loadings and can degrade mechanical and other properties. Toxicity of antimony-based retardants is a concern. Can be used with other flame retardants synergistically. 

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