Quaternary amines molecular weight

Anionic extractants are commonly based on high molecular weight amines. Metal anions such as MnO or ReO can be exchanged selectively with inorganic anions such as Cl or The equiHbrium for a quaternary onium compound of organic radicals R for two anion species A and B ... 

There are no universally accepted wet analytical methods for the characteri2ation of quaternary ammonium compounds. The American Oil Chemists Society (AOCS) has estabhshed, however, a number of appHcable tests (180). These include sampling, color, moisture, amine value, ash, iodine value, average molecular weight, pH, and flash point. 

The tertiary and quaternary amine bases are viscous liquids at room temperature and infinitely soluble in nonpolar solvents, but only slightly soluble in water. The solubility of the ion-pair RNH L in organic solvents depends on the chain length and on the counterion, LT the solubility of TLA HCl in wet benzene is 0.7 M, in cyclohexane 0.08 M, in CHCI3 1.2 M, and in CCI4 0.7 M. Nitrate and perchlorate salts are less soluble, as are lower molecular weight amines. 

The compatibility of the quaternary amlne-contalnlng NTMP with the nltrlle-modlfled epoxy adhesive, which leads to a bond that falls only within the adhesive (l.e., cohesive failure) can be explained. The FM 123-2 adhesive contains the storage-stable curing agent, dlcyanodlamlde, which does not release low-molecular weight amines until It becomes soluble In the resin above 90°C. (Equation 2) (25)... 

Of course the tertiary amine terminated polymer thus produced Is capable of being quaternlzed by alkyl halides and this has been confirmed experimentally. Moreover, It can be reacted with further living polyTHF to yield a polymer possessing a quaternary ammonium salt moiety at a point along the chain controlled by the relative molecular weights of the two living THF polymers reacted In the system, and again experiments have shown this to occur. 

RESINS (Acetal). These are thermoplastic resins, obtainable both as homopolymers and copolymers, and produced principally from formaldehyde or formaldehyde derivative. Acetal resins have the highest fatigue endurance of commercial thermoplastics. A variety of ionic initiators, such as tertiary amines and quaternary ammonium salts, are used to effect polymerization of formaldehyde. Chain transfer, shown by the following reactions, controls the molecular weight of resulting resins ... 

Once DNA has been condensed by a polycation, it is important for these complexes to retain a certain level of stability in salt solutions to allow sufficient time for cellular uptake of the particles. Izumrudov et al. (1999) studied the stability of a variety of polymers including polyvinylpyridines, linear poly amines, branched polyamines, polymethacrylates, and polyamides in salt solutions at a variety of pHs. They observed that polymers with predominantly primary amines produced the most stable polymer/DNA complexes followed by tertiary then quaternary amines, while higher molecular weight polymers resulted in more stable complexes for all amine types. Thus, it may be possible to specifically control complex stability by adjusting the relative amount of each amine type in the polymer. 

Indications. A violet, blue-violet, brown-violet, or GREY-VIOLET precipitate suggests the presence of an alkaloidal base (precipitated as the alkaloid-iodoplatinate complex). The clearest colours are obtained with tertiary and quaternary amines primary amines give indistinct colours and amines of small molecular weight do not generally react. 

Included in this category are the high-molecular weight primary amines (Primene JMT) secondary amines (Amberhte LA-2) tertiary amines (TOA, TNOA, Alamine 336) and quaternary alkylammonium salts (Aliquat 336). 

Alkyl ammonium compounds. High-molecular-weight amines are very useful actinide extractants in both analytical and process applications. Salts of primary, secondary, and tertiary amines, as well as quaternary ammonium bases RNH2, R2NH, R3N, and R N, are commonly used. These compounds, which are often thought of as anion exchangers, may also be considered as neutral-species coordinators since equivalent equilibrium expressions can be written based on either mechanism. That is,... 

High molecular-weight amines are of particular importance in the extraction [35-39]. They form ion-associates with acids (e.g., HSCN, HReOa, HI), metal-complex acids [e.g., H2PtCl6, HFeCU, H2U02(S04)2]2, and heteropoly acids. These complexes are extractable into non-polar solvents (e.g., CeHa, CHCI3, CCI4) and polar solvents (e.g., MIBK, amyl alcohol). Tertiary amines, such as tribenzylamine (TBA) and tri-n-octylamine (TOA) are most commonly used. Tertiary and secondary amines are used for extraction of anions from acid solutions, whereas quaternary ammonium salts enable also extraction from neutral and alkaline solutions. Secondary and tertiary amines and quaternary ammonium salts are applied as solutions in non-polar solvents. Diphenylguanidine (formula 1.13) is also frequently used in extraction. 

The quaternization of amines to the quaternary ammonium salt has proved a very useful method of converting the soft amine base to the pH insensitive quaternary ammonium salt. The amine is reacted with an appropriate measure of an alkyliodide as first described by Menshutkin (106). This reaction was systematically examined by Arcus and Hall in the 1960s as a means of quaternizing preformed polymers (107), and has emerged as a method of choice. For example, thwarted in our efforts to solubilize a high molecular weight... 

SPILL CLEAN-UP use water spray to "knock down" dust use solvent extraction with high molecular-weight amines and quaternary ammonium compounds for the removal or arsenic from industrial effluents. 

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