Triethanolamine TEA

Triethanolamine of formula N(C2H40H)3 is an oily water-soluble liquid having a fishy odor and is produced by reacting ammonia with ethylene oxide. Normally it is used in combination with other chemicals in admixture formulations. Its first use was reported in 1936, and the formulation containing TEA interground with calcium lignosulfonate was used to increase early strengths. 

Ramachandran followed the hydration of CjA (with and without gypsum) containing triethanolamine. It was found that TEA accelerated the hydration of C3A to the hexagonal aluminate hydrate and its conversion to the cubic aluminate hydrate. The formation of ettringite was also accelerated in the C3A-g q)sum-H20 system. 

In a study of the effect of 0, 0.1,0.5, and 1.0% triethanolamine on the hydration of C3S and C2S, Ramachandran concluded that there was an initial retardation of hydration. At one day, acceleration of hydration took place, thus TEA can be construed as a delayed accelerator. 

Amine salts are used in combination with other chemicals. Kuroda, et al.,[ l tested the effect of a formulation containing calcium nitrite, calcium rhodonate, and TEA. Both initial and final setting times were accelerated by this admixture combination at 5 and 20°C. The compressive strength of concrete also increased at these temperatures. 

Calcium formate, of formula Ca(HCOO)2, is a by-product in the manufacture of polyhydric alcohol, pentaerthritol. It is a powder and has a solubility of about 15% in water at room temperature. It is a non-chloride chemical that is used in practice. Many non-chloride accelerating admixture formulations contain formates. Calcium formate is an accelerator for the hydration of C3S at equal concentration, however, CaCl2 is more effective (Fig. 

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Activated tertiary amines such as triethanolamine (TEA) and methyl diethanolamine (MDEA) have gained wide acceptance for CO2 removal. These materials require very low regeneration energy because of weak CO2 amine adduct formation, and do not form carbamates or other corrosive compounds (53). Hybrid CO2 removal systems, such as MDEA —sulfolane—water and DIPA—sulfolane—water, where DIPA is diisopropylamine, are aqueous alkaline solutions in a nonaqueous solvent, and are normally used in tandem with other systems for residual clean-up. Extensive data on the solubiUty of acid gases in amine solutions are available (55,56). 

Fig. 7. Chelation of iron by triethanolamine (TEA) in aqueous sodium hydroxide.

Formulated products tend to use a 10 to 20% neutralized erythorbate, buffered to pH of 5 to 6 with ammonia, morpholine, cyclohexy-lamine, diethanolamine (DEA), or triethanolamine (TEA) to reduce the acidity of erythorbic acid. Similarly, amines are used with sodium erythorbate to improve the reaction rate. 

Cooling the solvent to 140 to 150 °F and then raising the pH to 9.5 to 10 with ammonia or triethanolamine (TEA) follows this step. 

NOTE Triethanolamine (TEA) also sequesters iron, is less toxic than ammonia, and reduces the risk of copper cracking. 

The most widely used amine is monoethanolamine (MEA), which is considered as a benchmark solvent because of its high cyclic capacity, significant absorption-stripping kinetic rates at low C02 concentration and high solubility in water. Some other amine-based solvents such as diethanolamine (DEA), triethanolamine (TEA), diglycolamine (DGA), N-methyldiethanol-amine (MDEA), piperazine (PZ), 2-amino-2-methyl-l-propanol (AMP) and N-(2-aminoeth-yl)piperazine (AEP) have also traditionally been utilised. 

Absorbents based on a variety of amines are by far the most common. Amines that have been used include monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), diisopropanolamine (DIPA), methyl diethanolamine (MDEA), and digly-colamine (DGA). C02 is typically absorbed at 80-140°F temperature and up to 1000 psig pressure by chemically reacting with the basic amine functional group in the absorbent, for example, primary amine, MEA, reacts with C02 by the following reaction forming a carbamate salt ... 

The mesoporous materials reported above are usually prepared from relatively expensive surfactants. Some of them have poor hydrothermal stability. Furthermore, the MCM-41 host structure has a one-dimensional pore system with consequent pore blockage and diffusion limitations. Shan et al. (52) reported the synthesis of a three-dimensional and randomly connected mesoporous titano-silicate (Ti-TUD-1, mesopore wall thickness = 2.5-4 nm, surface area — 700-1000 m2/g, tunable pore size —4.5-5.7 nm) from triethanolamine (TEA). Ti-TUD-1 showed higher activity (about 5.6 times) for cyclohexene epoxidation than the framework-substituted Ti-MCM-41. Its activity was similar to that of the Ti-grafted MCM-41 (52). 

DIPSO (3-[bis(2-hydroxyethyl)amino]-2-hydroxypropane- 1-sulfonic acid) Triethanolamine (TEA)... 

This category of admixture is based mainly on the major raw materials, calcium chloride, calcium nitrate, calcium formate [2] and calcium thiocyanate, with minor amounts of other materials occasionally being included in the formulations, such as calcium thiosulfate [3] and triethanolamine (TEA). TEA is not normally used alone but because it is sometimes used in other categories of admixture to compensate for retarding influences it will be included in this section. 

Table II is a list of gases which could potentially interfere with an N0 analysis along with the concentrations of these gases which produce a signal equivalent to 1 ppm N0. Only H2S had an effect on sensor cell performance and was found to decrease the response level by 0.2 a/ppm. H2S, SO2 and NO2 were effectively filtered from the gas stream by use of triethanolamine (TEA) as shown in Table II. To prevent TEA vapors from reaching (and thus poisoning) the sensing electrode surface, a short column of a cation exchange bead was placed after the filter.

Based on the research of Dr. E. D. Palmes (1) at New York University s Institute of Environmental Medicine and on additional study supported by a contract from the United States Bureau of Mines, a unique personal sampler has been designed to passively collect N0X. This is accomplished by way of molecular diffusion and subsequent trapping of the molecules onto a matrix coated with triethanolamine (TEA) at the closed end of the sampler. Constructed of polypropylene, the tubular sampler shown in Figure 1 is small, lightweight, unbreakable and can be easily worn in the breathing zone of the employee whose exposure is to be monitored. No pumping mechanism is required. The components of N0X diffuse at constant, known rates towards the sealed end of... 

The fuel selected for use with HAN should be totally compatible and therefore, nitrate salts of amines are the natural choice for this purpose. Based on a study with aliphatic, aromatic and heterocyclic amines, aliphatic amines are considered a better choice and a formulation containing the nitrate salt of triethanolamine (TEA), that is, TEAN [(CH2OHCH2)3 NHNOJ is currently in use. HAN-based propellants consist of HAN, water and TEAN. Some typical formulations of LGP are given in Table 4.2 along with their properties. These three propellants differ from one another only in respect of the amount of water which they contain. 

Sodium lauryl sulfate (anionic surfactant) Stepan Bio Soft D-62 (LAS-anionic surfactant Triethanolamine (TEA)... 

A difference in reaction selectivity is also observed between that complex obtained from 2 and triethanolamine (TEA) and that from diethanolamine (DEA). That catalyst obtained from 2 and TEA is capable of hydrogenating TMBC (7), albeit very slowly, but that obtained from DEA is inactive in this reaction (Table V). 

Air drawn through Palmes tube with three triethanolamine (TEA)-treated screens analyte converted into nitrite ion (NO, ) NO, treated with an aqueous solution of a reagent mixture containing sulfanilamide, H3P04, and V-1 -naphthy 1-ethylenediamine dihydrochloride color develops absorbance measured at 540 nm by a spectrophotometer, concentration determined from a standard calibration curve made from NaN02 (NIOSH Method 6700, 1984). 

Diethanolamine (DEA) This chemical, and its compounds, which include triethanolamine (TEA), is found in shampoos and other products and is suspected to be a carcinogen. 

PCTEA is a Phenidone-ascorbic acid developer with triethanolamine (TEA for short) activator. Using this formula, I can t find the grain in HP5+ orTMAX 400 at less than a 20-power enlargement. Even in very thin negatives of low contrast, shadow detail is still apparent. The following formula may be scaled up to any desired amount. 

Start with about 8.0ml of triethanolamine (TEA) at room temperature and a spoonful of water. Now add 2.5 grams of metol and stir to make a slurry. This is eventually going to make a liter but you can start in a 1/4-liter cup. After the slurry gets a little more fluid, add 15.0 to 20.0ml of some warm propylene glycol. Now you can transfer the metol slurry to the 750.0ml of warm propylene glycol and stir until dissolved. Now add 50.0 grams of pyrocatechin and stir until dissolved. Add 4.0 grams of ascorbic acid and stir until dissolved. Stock B is mixed the same as for Pyrocat-HD. 

Hence, activated tertiary amines such as triethanolamine (TEA) and methyl diethanolamine (MDEA) have now gained wide acceptance for CO2 removal. These materials require very... 

Sulfite and bisulfite in rain water are rapidly oxidized to sulfate by the catalytic effect of metallic ions such as Fe(III) and Mn(II). The rates of oxidation of S(IV) in test solutions were measured using ion chromatography. The rate constant, k, measured for a 12.5 yM S(IV) solution was found to be 0.6-10.4 hr 1 at pH 3-6 in the presence of 1.8-yM Fe(III) and 0.18 yM Mn(II) catalysts, and 0.4-5.9 x 10 J hr 1 without the catalysts. Triethanolamine (TEA) was used to stabilize actual rain water samples prior to analysis. 

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