DETA

The mechanism of dielectric effects of interest to DETA involves permanent dipoles which exist within the sample and try to follow an alternating electric field, but may be hindered to do so when attached to segments of molecules with limited mobility. The fundamental analogy of dielectric and mechanical relaxation has been pointed out 

An electric field in a material causes polarization, as summarized in Fig. 4.171. The polarization may have different origins (1) Electron polarization, an interaction that shifts the electrons with respect to the center of the atom. (2) Atom polarization, caused by shift of relative positions of bonded atoms. (3) Dipole or orientation polarization, the effect to be discussed. The first two types of polarization involve fast displacement of positive and negative charges relative to each other within a time-scale of about 10 s. Both are usually treated together as induced polarization and are related to the refractive index, n, by the equation of Maxwell (see also the discussions of light scattering. Sect. 1.4.2 and Appendix 3). The time scale of dipole polarization is 10 to 10 s for mobile dipoles, but may become seconds and longer 

The electric polarizability of a molecule is defined by the induced electric dipole p = aE, where E is the electric field strength (in V/m). The SI unit of o( is C m2 V-T 

The macrosoopic polarization of a dielectric, P, is the average dipole moment per unit volume or charge per unit area. The connection between the definitions can be gained from the sketoh  

The molecular dipoles of the dielectric align in the applied field and give rise to the opposing charges (-PA on the right and +PA on the left), but cancel in the bulk. 

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This section provides an overview and review of qtiariititn niech antes calculation s. The in formation can help yon nsellyper-Chern to sol ve p radical problem s. for quan litati ve deta ils o f quan-turn m ecli an ics calculation s an d how HyperChern implements them, see the second part of this book, I heoiy and Methods. 

CastabEity is not to be confused with fluidity, which is the abEity of a molten aEoy to fEl a mold cavity iu every detaE. CastabEity is the ease with which an aEoy responds to ordinary foundry practice without undue attention to gating, risering, melting, sand conditions, and any other factors involved in producing sound castings. 

Aldehydes. Alkyleneamines react exothermically with ahphatic aldehydes. The products depend on stoichiometry, reaction conditions, and stmcture of the alkyleneamine. Reactions of aldehydes with ethyleneamines like EDA or DETA give mono- and disubstituted imidazohdines via cyclization of the intermediate Schiff base (20). 

DETA has been produced by reaction of monoethanol amine [141-43-5] (MEA) and EDA with urea (42). In this process, MEA reacts with urea to form 2-oxa2ohdinone which then reacts with EDA to form the cycHc urea of diethylene-triamine. Hydrolysis of the ureaHberates the free amine. 

Determination of ethyleneamines in air can be accomplished by absorbing the amines on NITC (1-naphthyl isothiocyanate) treated XAD-2 resin, then desorbing the derivative from the treated tubes and quantifying the amount using high performance Hquid chromatography (hplc). Sensitivity is reported as 0.37 and 0.016 mg/m for EDA and DETA, respectively, pet sample (153,154). 

Other modifications of the polyamines include limited addition of alkylene oxide to yield the corresponding hydroxyalkyl derivatives (225) and cyanoethylation of DETA or TETA, usuaHy by reaction with acrylonitrile [107-13-1/, to give derivatives providing longer pot Hfe and better wetting of glass (226). Also included are ketimines, made by the reaction of EDA with acetone for example. These derivatives can also be hydrogenated, as in the case of the equimolar adducts of DETA and methyl isobutyl ketone [108-10-1] or methyl isoamyl ketone [110-12-3] (221 or used as is to provide moisture cure performance. Mannich bases prepared from a phenol, formaldehyde and a polyamine are also used, such as the hardener prepared from cresol, DETA, and formaldehyde (228). Other modifications of polyamines for use as epoxy hardeners include reaction with aldehydes (229), epoxidized fatty nitriles (230), aromatic monoisocyanates (231), or propylene sulfide [1072-43-1] (232). 

In the adhesives area, thermoplastic, fatty polyamides are used in hot-melt and heat-seal adhesives for leather, paper, plastic and metal. Blends of EDA- and DETA-based polyamides are suggested for use in metal can seam sealants with improved toughness (234) pressure sensitive adhesives have been formulated with DETA-based polyamides (235) and anionic and cationic suspensoid adhesives are used as heat-seal coatings in paper converting (236). PIP and certain PIP derivatives are used with EDA in some appHcations (237). 

Thermoplastic polyamides are used in coatings to modify alkyd resins (qv) in thixotropic systems (238) and to plasticize nitroceUulose lacquers (239). DETA-taH oil fatty acid-based polyamides are suggested for use as corrosion inhibitors in alkyd paints (240). Printing inks for fiexo-gravure appHcation on certain paper, film and foil webs rely on EDA- and PDA-based polyamides for their specific performance (241). 

Another significant end-use for polyamines is in preparation of paper wet-strength resins. These are polyamide, modified formaldehyde, and polyamine resins used to improve the physical strength of tissue, toweling, and packaging paper products. The cationic formaldehyde resins include both urea—formaldehyde and melamine—formaldehyde types (248,249). Cationic functionaHty is imparted by incorporation of DETA, TETA, and/or TEPA in... 

Pigment retention and drainage additives made with polyamines include polyamines made from ethyleneamines, ethan olamines, and epichl orohydrin (262) ethyleneamines combined with phosphoms-modifted polyamines made by reaction of ethyleneamines with POCl [10025-87-3] (263) and a DETA—glutaric acid polyamide crosslinked with PEG-bis(3-chloro-2-hydroxypropyl) ether (264). Polyamines made from ethyleneamines and EDC are useful flocculating agents (265). 

Fabric Softeners, Surfactants and Bleach Activators. Mono- and bisamidoamines and their imidazoline counterparts are formed by the condensation reaction of one or two moles of a monobasic fatty acid (typically stearic or oleic) or their methyl esters with one mole of a polyamine. Imidazoline formation requires that the ethyleneamine have at least one segment in which a secondary amine group Hes adjacent to a primary amine group. These amidoamines and imidazolines form the basis for a wide range of fabric softeners, surfactants, and emulsifiers. Commonly used amines are DETA, TETA, and DMAPA, although most of the polyethylene and polypropane polyamines can be used. 

Many of the surfactants made from ethyleneamines contain the imidazoline stmcture or are prepared through an imidazoline intermediate. Various 2-alkyl-imidazolines and their salts prepared mainly from EDA or monoethoxylated EDA are reported to have good foaming properties (292—295). Ethyleneamine-based imida zolines are also important intermediates for surfactants used in shampoos by virtue of their mildness and good foaming characteristics. 2- Alkyl imidazolines made from DETA or monoethoxylated EDA and fatty acids or their methyl esters are the principal commercial intermediates (296—298). They are converted into shampoo surfactants commonly by reaction with one or two moles of sodium chloroacetate to yield amphoteric surfactants (299—301). The ease with which the imidazoline intermediates are hydrolyzed leads to arnidoamine-type stmctures when these derivatives are prepared under aqueous alkaline conditions. However, reaction of the imidazoline under anhydrous conditions with acryflc acid [79-10-7] to make salt-free, amphoteric products, leaves the imidazoline stmcture essentially intact. Certain polyamine derivatives also function as water-in-oil or od-in-water emulsifiers. These include the products of a reaction between DETA, TETA, or TEPA and fatty acids (302) or oxidized hydrocarbon wax (303). The amidoamine made from lauric acid [143-07-7] and DETA mono- and bis(2-ethylhexyl) phosphate is a very effective water-in-od emulsifier (304). 

The derivatives used in corrosion inhibitor formulations for down-hole use constitute a significant industrial appHcation for polyamines. Again, mono- and bisarnidoamines, imidazolines, and polyamides made from the higher polyamines are the popular choices. The products made from DETA and fatty acids have been widely used (308). A wide variety of other polyamine-based, corrosion inhibiting derivatives have been developed, generally incorporating some form of oil-soluble or od-dispersible residue. Sulfur and its derivatives are also used in these polyamine-based corrosion inhibitors on... 

Ethyleneamines are used in certain petroleum refining operations as well. Eor example, an EDA solution of sodium 2-aminoethoxide is used to extract thiols from straight-mn petroleum distillates (314) a combination of substituted phenol and AEP are used as an antioxidant to control fouling during processing of a hydrocarbon (315) AEP is used to separate alkenes from thermally cracked petroleum products (316) and TEPA is used to separate carbon disulfide from a pyrolysis fraction from ethylene production (317). EDA and DETA are used in the preparation and reprocessing of certain... 

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