Amidoamines

Amidoamine or polyamidoamine curing agents have reactivity with DGEBA epoxy resins that is similar to the polyamides. However, they are lower-viscosity products and are also lower in color. Amidoamines are derivatives of monobasic fatty carboxylic acids and aliphatic polyamines. Since the amidoamines have only one amide group per molecule, they are lower in molecular weight, viscosity, and amine functionality than the polyamides. 

Both the polyamide and amidoamine curing agents can be accelerated by the addition of a tertiary amine such as DMP-10, tris(dimethylamino methyl) phenol. 

Some products in the amidoamine group are manufactured to contain a significant amount of imidazoline structures. This is accomplished by a high reaction temperature that converts the open amide structure to the cyclic imidazolin with loss of water. This conversion leads to lower viscosities since the concentration of the polar amide group is reduced. 

Amidoamines exhibit very good adhesion characteristics, particularly to porous substrates such as concrete and wood. They also cure extremely well under humid conditions. They are much less corrosive than aliphatic amines and provide less skin irritation. 

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Fats, Oils, or Fatty Acids. The primary products produced direcdy from fats, oils, or fatty acids without a nitrile iatermediate are the quatemized amidoamines, imidazolines, and ethoxylated derivatives (Fig. 3). Reaction of fatty acids or tallow with various polyamines produces the iatermediate dialkylarnidoarnine. By controlling reaction conditions, dehydration can be continued until the imidazoline is produced. Quaternaries are produced from both amidoamines and imidazolines by reaction with methyl chloride or dimethyl sulfate. The amidoamines can also react with ethylene oxide (qv) to produce ethoxylated amidoamines which are then quaternized. 

Fig. 3. Quatemaiies fiom amidoamines and imidazolines where R is a fatty alkyl group.

These compounds and their derivatives can be manufactured using relatively simple equipment compared to that required for the fatty nitrile derivatives. Cyclization of amidoamines to imidazolines requires higher reaction temperatures and reduced pressures. Prices of imidazolines are therefore high. 

The incorporation of metal salts of amphoteric surface active agents (Mostat Series) as internal antistatic agents in polypropylene fibers has been reported (95). Metal salts of alanine, amidoamine, and imida2oiine-type amphoteric surface-active agents show excellent performance as internal antistatic agents and also improve the dyeing abiUty of the fibers with acid dyes. 

Organic Acids and Their Derivatives (Anhydrides, Nitriles, Ureas). Alkyleneamines react with acids, esters, acid anhydrides or acyl hahdes to form amidoamines and polyamides. Various diamides of EDA are prepared from the appropriate methyl ester or acid at moderate temperatures (25,26). 

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 synthesis and surface-active properties of higher hydroxyalkanediphos-phonates are discussed in Ref. 67. Phosphorus-containing betaines as hydrolytically stable surfactants, free from alkali salt impurities, were prepared by a reaction of amidoamines and equimolar amounts of phosphonate esters with 1.5-2 eq of formaldehyde at 60-140°C in a polar solvent [72]. 

Fig. 2. Poly(amidoamine) (PAMAM) dendrimers with carboxylate groups at the external surface...

Anionic poly(amidoamine) (PAMAM) dendrimer was selected as a model of the soluble acidic-rich proteins to prepare CaC03 film on a poly(ethylenimine) film [49]. The CaCOj/polylethylenimine) composite film was obtained in the... 

D. Page and R. Roy, Synthesis and biological properties of mannosylated starburst Poly(amidoamine) dendrimers, Bioconjug. Chem., 8 (1997) 714—723. 

Hartmann L, Hafele S, Peschka-Suss R, Antonietti M, Bomer HG (2008) Tailor-made poly (amidoamine)s for controlled complexation and condensation of DNA. Chemistry 14 2025-2033... 

The synthesis and structure of a dendrimer can be illustrated by the well-known poly (amidoamine) type (called PAMAM), which describes the monomers making up the complete polymer. The synthesis starts from a core diamine (or ammonia) molecule. The diamine can be of various lengths and spacer arm properties and even contain cleavable components. Typically, the core... 

Hong, M.-Y., Yoon, H.C., and Kim, H.-S. (2003a) Protein-ligand interactions at poly(amidoamine) den-drimer monolayers on gold. Langmuir 19, 416—421. 

Huang, B., and Tomalia, D.A. (2005) Dendronization of gold and CdSe/cdS (core-shell) quantum dots with tomalia type, thiol core, functionalized poly(amidoamine) (PAMAM) dendrons. J. Lumin. Ill, 215-223. 

Majoros, I., Thomas, T.P., Mehta, C.B., and Baker Jr., J.R. (2005) Poly(amidoamine) dendrimer-based multifunctional engineered nanodevice for cancer therapy./. Med. Ghent. 48, 5892-5899. 

The team of Crooks is involved in the synthesis and the use of dendrimers and, more particularly, poly(amidoamine) dendrimers (PAMAM), for the preparation of dendrimer-encapsulated mono- or bimetallic nanoparticles of various metals (Pt, Pd, Cu, Au, Ag, Ni, etc.) [55, 56]. The dendrimers were used as nanocatalysts for the hydrogenation of allyl alcohol and N-isopropylacrylamide or other alkenes under different reaction conditions (water, organic solvents, biphasic fluorous/or-ganic solvents or supercritical COz). The hydrogenation reaction rate is dependent on dendrimer generation, as higher-generation dendrimers are more sterically... 

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