Technical Specifications:
If RXH is not acid enough to release a proton at alkaline pH, as it is the case with amines, then the reaction has to be carried out in two steps. During the first step the first EO mole is added at acid pH, so that the amine is transformed in ammonium. The reaction produce the mono-, di- and tri-ethanol amines.
Proton release from ammonium NH4+ %u2192 NH3 + H+ (here RX– is NH3) Then, the three condensation reactions:
NH3 + EO %u2192 NH2CH2CH2OH (mono-ethanol amine MEA)
NH2CH2CH2OH + EO %u2192 NH(CH2CH2OH)2 (di-ethanol amine DEA)
NH-(CH2CH2OH)2 + EO %u2192 N(CH2CH2OH)3 (tri-ethanol amine TEA)
With an alkyl amine, first the alkyl ammoniumion is formed and it is deprotonated:
RNH3+ %u2192 RNH2 + H+ (here RX– is RNH2)
RNH2 + EO %u2192 RNH-CH2CH2OH (mono-ethanol alkyl amine)
RNH-CH2CH2OH + EO %u2192 RN(CH2CH2OH)2 (di-ethanol alkyl amine)
Once the ethanol amine is attained, the EO polycondensation is carried out at alkaline pH as previously. In many instance the first ethoxylation is stopped when the monoethanol alkyl amine is formed in order to avoid the polycondensation in more than one chain.
Application:
| PRODUCT NAME | : | TRI ETHANOL AMINE |
| CAS number | : | 102-71-6 |
| UN number | : | |
| Formula | : | (HOC2H4)3N |
| Odour | : | SLIGHTLY AMMONIACAL |
| Solubility in water | : | COMPLETE |
| Density | : | 1.13 at 20 oC |
| Boiling point | : | 360 oC |
| Melting point | : | 21 oC |
| Viscosity | : | |
| Flashpoint | : | 190 oC |
| Explosive limits | : | 1.2 – ? Vol% |
| Vapour pressure | : | .03 mbar at 20 oC |
| Skin absorption/irritation | : | YES |
| TLV Country NL Year 1995 | : | |
| Pollution category 1994 | : | D |
Note: This article uses material from the http://rxmarine.com/