Ammonium salts anionic polymerization

Polystyryl quaternary ammonium salts (anionic polymerization AP-PSQAS)... 

Solvent polymeric membranes that incorporate quaternary ammonium salt anion-exchangers, such as tri-n-octylpro-pylammonium chloride decanol, are used to construct CP-selective electrodes in clinical analyzers. Although by far the most common method for measuring CP in clinical laboratories, these electrodes have been described to suffer from membrane instability and lot-to-lot inconsistency in selectivity to other anions. " Anions that tend to be problematic are other halides and organic anions, such as SCN", which can be particularly problematic because of their ability to solubilize in the polymeric organic membrane of these electrodes. 

Protonic initiation is also the end result of a large number of other initiating systems. Strong acids are generated in situ by a variety of different chemistries (6). These include initiation by carbenium ions, eg, trityl or diazonium salts (151) by an electric current in the presence of a quartenary ammonium salt (152) by halonium, triaryl sulfonium, and triaryl selenonium salts with uv irradiation (153—155) by mercuric perchlorate, nitrosyl hexafluorophosphate, or nitryl hexafluorophosphate (156) and by interaction of free radicals with certain metal salts (157). Reports of "new" initiating systems are often the result of such secondary reactions. Other reports suggest standard polymerization processes with perhaps novel anions. These latter include (Tf)4Al (158) heteropoly acids, eg, tungstophosphate anion (159,160) transition-metal-based systems, eg, Pt (161) or rare earths (162) and numerous systems based on tri flic acid (158,163—166). Coordination polymerization of THF may be in a different class (167). 

Ammonium salts of alkenyl succinic half-amides have teen described for use as corrosion inhibitors in oil and gas production technology to combat corrosion by media containing CO2, H2S, and elemental sulfur [1366]. The inhibitor composition may contain a dispersing agent, such as a low molecular weight or polymeric anionic surfactant like an alkylsulfonic acid or an alkyl-aryl sulfonic acid. 

Quaternary ammonium salts (QAS) are anion exchangers used in solvent polymeric membranes. Variation of substituents at the nitrogen atom is an option for tuning QAS... 

For the anionic polymerization of methacrylonitrile (MAN), many initiators have been developed, which include alkali-metal alkyls such as butyllithium [42], triphenylmethylsodium [43], phenylisopropylpotassium [43], the disodium salt of living a-methylstyrene tetramer [44], alkali-metal amides [45], alkoxides [46], and hydroxide [47], alkali metal in liquid NH3 [48], quaternary ammonium hydroxide [49], and a silyl ketene acetal coupled with nucleophilic or Lewis acidic catalysts [50]. However, only a single example of the synthesis of PMAN with narrow molecular-weight distribution can be cited, and the reported number-average molecular weights were much higher than those calculated from the stoichiometry of the butyllithium initiator [42]. 

It was shown from the study of styrene and MMA in a KNOa-DMF system using tracer techniques for the composition analysis that the free-radical contribution is apparently confined to the first few percent of polymerization, whereas at later stages the reaction is anionic (34). This is consistent with the inhibitor studies. On the same monomer pair with a variety of solvents with ammonium salts, only with tetrahydrofuran did a possible free-radical reaction accompany the anionic propagation, with the others, DMF and dimethylacetamide, as well as without solvent, an anionic reaction accompanying the free radical one was assumed (35). 

Nitrides can be obtained by decomposition of the azides, but thermolysis of the pentahalides with ammonium salts appears more general. Recent synthetic pathways involve the cleavage of N2 or decarboxylation of a Nb isocyanate." The solid-state characterization of the [M2NXio] anions shows a linear symmetrical M=N=M bridge. Neutral halide nitrides are polymeric. Heterometallic nitrides based on a comer-shared double cube NbTieNg core (27) have been described (equation 14). ... 

A possible strategy to improve control of the anionic polymerization of methacrylates relies on the substitution of metal-free cations for metal cations. Ammonium and phosphonium salts were investigated as discussed hereafter. 

Alkyl phenol ethoxylates have been over many years the workhorses as nonionic emulsifiers for emulsion polymerization. Depending on availability and price of buten and propen, nonyl (tripropylene)phenol ethoxylates or octyl (dibutylene) phenol ethoxylates have been very broadly used, whereas dodecyl (tetrapropylene or tributylene)phenol and tri tert-butylphenol ethoxylates were merely regarded as specialties. These aUcyl phenol ethoxylates can also be used as intermediates for the synthesis of anionic alkyl phenol ether sulphates. Sulphation by chlorosul-phonic acid or sulphur trioxide besides formation of the ether sulphate end group inevitably leads to certain amounts of ring sulphonation in the phenyl group, whereas amidosulphonic acid gives sulphonate-free aUcyl phenol ether sulphate ammonium salts. 

The cationic copolymerization was carried out in air at 25°C in a nitrobenzene solution using stannic bromide as catalyst, while the anionic polymerization was studied in air with sodium dissolved in anunonia [186]. Although many monomers may be polymerized by quaternary ammonium salts, vinyl acetate does not produce any polymer on treatment with dimethylphenylbenzylammonium chloride [187]. 

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