Tertiary-methyldiethanolamine

Amine-based solvents have been enhanced over the years [2], such that primary (Monoethanolamine (MEA) Diglycolamine (DGA)), secondary (Diethanolamine (DEA) Diisopropanolamine (DIPA)) and tertiary (Methyldiethanolamine (MDEA) Triethanolamine (TEA)) variants are available through different suppliers, many of which include special proprietary additives to improve performance and other characteristics. The choice of a particular alkanolamine is primarily dictated by the requirements of the specific application. With the exception of a few, these amines have a maximum sorption capacity of 1 mole of CO2 to two moles of amines. Liquid tertiary amines and amidines have shown a higher sorption capacity with a ratio of 1 1 molar [3], thereby reducing the volume of amine, but the reaction rate is much slower. Amine blends have been used to compensate for this difference in order to reduce regeneration and recirculation costs and increase CO2 loading capacity. 

Amine solvents are widely used for sour gas removal, in syngas, fertilizer and natural gas plants. They are mainly used to withdraw the sour components CO2 and H2S from process gas streams, and the process is usually carried out in packed-bed columns. Depending on the specifics of a particular process, either aqueous primary (e.g., monoethanolamine, MEA), secondary (e.g., diethanolamine, DEA), tertiary (e.g., methyldiethanolamine, MDEA) amines or aqueous amine blends are employed. 

While poly (ortho esters) are add-sensitive, their sensitivity is not sufficient for use in a self-regulated insulin delivery system. However, when a diol contains a tertiary amine in the backbone is used, the pH-sensitivity is enormously increased. The structure of a polymer from 3,9-bis (ethylidene 2,4,8,10-tetraoxas-piro [5,5] undecane) and /V-methyldiethanolamine is shown in Scheme 17. 

The performance of a new photoinitiator, diphenoxybenzophenone (DPB), has been evaluated and compared to benzophenone (BZP) and Irgacure 651. DPB was synthetized by phosgenation at 9QPC of diphenyletiier in the presence of AICI3. A small amount of a tertiary amine, methyldiethanolamine (MDEA), had to be introduce in the formulation since, like for BZP, the radical production upon photolysis proceeds by hydrogen transfer from the donor molecule to the excited state of DPB. 

Lee et al. (1990) studied the PV of EtOH-water mixtures by cationic-anionic interpenetrating polymer network (IPN) membranes. The cationic PU prepared by quaternizing the tertiary amine from A -methyldiethanolamine and the anionic acrylic copolymer from acrylic acid were used as the cationic and anionic components. The separation factor increased as the content of the anionic component in the membrane increased. The ion content in the membrane was also found to be an important factor for the optimum permseparation of water. Better performance was achieved by PEG-based PU as the cationic component of the IPN membrane. The highest selectivity was observed for the IPN membrane with 10 wt% of PEG-based PU. 

When photoinitiators consisting of mixtures of benzophenone, or 4-benzoylbiphenyl, or isopropylthioxanthone vdth a tertiary amine are combined with an electron deficient anhydride, rapid photoinitiations of polymerizations of acrylate esters result. Thus, additions of less than 0.1 wt. percent 2,3-dimethylmaleic anhydride to 1,6-hexanediol diacrylate containing any of the above diaryUcetones and N-methyldiethanolamine result in an increase in the polymerization rate maximum by a factor of as much as three that is attained for the same reaction without the anhydride. Laser flash photolysis results show that benzophenone, 4-benzoylbiphenyl, and isopropylthioxanthone triplets are readily quenched by dimethylmaleic anhydride. 

Tertiary amines cannot form carbamates, but they react with CO2 in aqueous solvents to form hydrogencarbonate (3.20). Yu and Astarita [29] studied the kinetics of the absorption of carbon dioxide in MDEA (bis(2-hydroxyethyl) methylamine 77-methyldiethanolamine) solutions and... 

Most often, the esterquats are prepared by reaction of a tertiary alkanolamine with a fatty acid, followed by reaction with an alkylating agent to the corresponding quaternary [6]. Other sources of the acyl chain include triglycerides, methyl esters, and acid chlorides. The reaction scheme for the preparation of the diester of bis-2-hydroxyethyldimethylammonium chloride from methyldiethanolamine and fatty acid is given in Fig. 3. 

Amines which have two hydrogen atoms directly attached to a nitrogen atom, such as monoethanolamine (MEA) and 2-(2-aminoethoxy) ethanol (DGA), are called primary amines and are genially the most alkaline. Diethanolamine (DBA) and Diisopropanolamine (DIPA) have one hydrogen atom directly attached to the nitrogen atom and are called secondary amines. Triethanolamine (TEA) and Methyldiethanolamine (MDEA) represent completely substituted ammonia molecules with no hydrogen atoms attached to the nitrogen, and ate called tertiary amines. 

Attributing corrosion to simple acid gas attack explains several observed corrosion phenomena. For example, primary amines, such as monoethanolamine (MEA) and Diglyco-lamine (DGA), are more corrosive than secondary and tertiary amines because in amine systems employing primary amines, which are difficult to strip, high concentrations of amine-acid gas salts are present in the hottest areas of the process. Conversely, methyldiethanolamine (MDEA), a tertiary amine, is easily stripped of both CO2 and H2S. Therefore, it is less corrosive because the bulk of the acid gas is evolved fiom solution at a lower temperature. 

Degradation of Methyldiethanolamine (MDEA) by CO Blanc et al. (1982A, B) state that there are no MDEA-CO2 degradation products. Since MDEA is a tertiary amine, it cannot form a carbamate ion and this may be the reason that it is not degraded by carbon dioxide. 

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