Polyethyleneimines

Polyethyleneimlnes.—Commercial polyethyleneimine (14) is prepared by ring opening polymerization of ethyleneimine (aziridine). This polymer is a highly 

Beckford, R. M. King, J. F. Stoddart, and R. F, Newton, Tetrahedron Letters, 1978,171. W. Dawydoff, Faserforsch. Textiltech., 1978, 29, 343 H. Hirai, Kobunshi, 1977, 26, 266 G. Manecke and W. Storck, Angew. Ckem. fnternat. Edn., 1978, 17, 657 H. Morawetz, React. Solids Proc. Internat. Symp., Sth, 1976, 465. 

Polyethyleneimine, benzylated to the extent of 10% of its nitrogen atoms (P), cleaves the disulphide bond of 5,5 -dithiobis-(2-nitrobenzoic acid) (Ellman s reagent) (RSSR) via a complexation step followed by nucleophilic attack on the sulphur to give a sulphenamide [equation (1)]. The binding constant (X) is 

6 X10 mol 1 but of the 5581 amino groups on the polymer molecule only ca. 10 form covalent bonds to sulphur. This is consistent with ca. 1— 2% of the benzyl groups providing a binding site close to a reactive amine. The polymer exhibits a 10 -fold rate enhancement compared with an amine of similar basicity. However, the effective molarity based on the comparison between cat and an analogous intermolecular reaction, is only 26 M which is attributed to a loose transition state or loose initial complex.  

Alkyl-substituted polyethyleneimines show maximum activity in catalysing the hydrolysis of 4-nitrophenyl esters when both the substrate and the catalyst contain long-chain alkyl groups.  

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Used industrially to cross-link hydroxylic polymers, polyethyleneimine. Possesses some carcinogenic properties. Polyethyleneimine is a hygroscopic liquid used in paper manufacture to confer wet strength and in textiles, alkylated derivatives also form useful polymers. 

Polyamines can also be made by reaction of ethylene dichloride with amines (18). Products of this type are sometimes formed as by-products in the manufacture of amines. A third type of polyamine is polyethyleneimine [9002-98-6] which can be made by several routes the most frequently used method is the polymeriza tion of azitidine [151 -56 ] (18,26). The process can be adjusted to vary the amount of branching (see Imines, cyclic). Polyamines are considerably lower in molecular weight compared to acrylamide polymers, and therefore their solution viscosities are much lower. They are sold commercially as viscous solutions containing 1—20% polymer, and also any by-product salts from the polymerization reaction. The charge on polyamines depends on the pH of the medium. They can be quaternized to make their charge independent of pH (18). 

Eig. 11. Composite hoUow-fiber production scheme (PEI = polyethyleneimine TDI = toluene 2,4-diisocyanate). Anisotropic (porous skin) polysulfone hoUow fiber is roUed into bath A and is lifted vertically (to avoid droplet formation) into a beating tube. The fiber is then passed through bath B and is... 

Linear polyethyleneimine results only in low yields from low temperature polymerization of ethyleneimine for very long reaction times. It can, however, be synthesized in a targeted manner by polymerization of 2-oxazolines with subsequent hydrolytic cleavage of the resulting polyamides (355,358). 

The polymerization of A/-(2-tetrahydropyranyl)aziridine with subsequent hydrolysis of the resulting polymers has been described as an alternative route for the synthesis of linear polyethyleneimine (359). Linear polyethyleneimine, in contrast to branched polyethyleneimines, is only sparingly soluble in water at room temperature. 

Textile Finishing. Polyethyleneimine-A/-methylolurea derivatives improve the crease and wear resistance of cotton (429,430). The adhesion between individual wool fibers is improved by pretreatment with amines, which leads to improved shrink resistance (431). An antimicrobial finish can be appHed to cotton by using a combination of PEI and ureas to bind zinc pyrithione to the fabric (432). After wool has been provided with a flameproof finish using fluorozirconate or fluorotitanate, the wool can be neutralized with PEI (433). Conventional neutralizing agents caimot be used for this purpose since they impair the flameproof characteristics of the impregnated fabric. 

Material Protection. The graft copolymers of ethylene sulfide on polyethyleneimine can be used as an antifouHng anticorrosion substrate for iron (439). PEIs or their derivatives are also used in electrolysis baths as brighteners in the electrochemical deposition of metals (440,441). 

Platinum—polyethyleneimine complexes prevent the division of bacteria, and are being tested as carriers in the treatment of cancer and vimses (445—447). Encapsulated PEIs containing nucleic acid bases activate the neutrophils in human blood (448). 

Miscellaneous Applications. PEIs and their derivatives ate used as cementation auxihaties in cmde oil exploration (459), and for breaking cmde oil emulsions (460) in cmde oil extraction. Seed coatings of water-soluble copolymers containing polyethyleneimine have been developed (461). Polyethyleneimine derivatives have positive photoresist properties (462) amidated polyethyleneimines improve the flow properties of cement (463) and with few exceptions, A/-acyla2iddines act as chemical sterilisers for insects (464). 

The possibility of inducing of pH gradients within thin long capillaries with flowing retentive stationary phase based on propylamine or polyethyleneimine was shown. 

Cationic hydrophobic Polyethyleneimine Poly(N-methyl-2-vinylpyridinium) salt 0.5 M NaOAc/ 0.5 M AcOH... 

It has been found that both bromination and chlorosulfonation reactions are very useful in coupling a wide range of bonded phases to the gels. It is possible to couple virtually any primary amine to brominated and/or chlorosulfonated PDVB gels. This has allowed the development of many other phases such as polyamino, octadecyl, polyethyleneimine, and quaternary amine. Figures 13.13-13.16 show an assortment of various bonded phases developed since the mid-1980s. 

The Jordi polyethyleneimine phase has been developed in an attempt to block adsorptive effects of the PDVB surfaces toward cationic polymers such as chitosan and quaternary water-soluble flocculants (Fig. 13.17). 

ACPA azobis(4-cyanopentanoic acid) AIBN azobis isobutyronitrile) BPO benzoyl peroxide DVB divinyl benzene, EGA 2-ethylcyano-acrylate HPC hydroxypropyl cellulose MMA methyl methacrylate PAAc polyacrylic acid PEI polyethyleneimine, PEO/PPO polyethylene oxide/polypyropylene oxide copolymer PVME polyvinylmethylether PVP polyvinylpyrrolidone K-30 DMSO dimethylsulfoxide PGA polyglutaraldehyde CMS chloromethylstyrene PMMA-g-OSA polymethylmethacrylate grafted oligostearic acid. 

Alpert and Regnier [37] found that polyethyleneimine (PEI, M = 600) was readily adsorbed by various porous silicas from a methanol solution. After the reversibly adsorbed portion of the polymer was washed out, the content of... 

The most possible reason may be in the higher free energy of the protein adsorption on PolyPROPYL A materials. Chemisorbed neutral poly(succinimide) of molecular weight 13000 apparently forms a diffuse interface as predicted by theory (see Sect. 2.2). Controversially, a short polyethyleneimine exists on a surface in a more flat conformation exhibiting almost no excluded volume and producing... 

In oil and gas well cementing operations, polyethyleneimine phosphonate-derivative dispersants enhance the flow behavior of the cement slurry [422]. The slurry can be pumped in turbulent flow, thereby forming a bond between the well casing and the rock formation. 

Linear polyethyleneimine is insoluble in benzene, diethyl ether, acetone, and water at room temperature and is soluble in hot water. 

Alkoxylated polyethyleneimines are obtained by reacting polyethylene-imine with a molecular weight of 2500 to 35,000 with an excess of propylene oxide and ethylene oxide with respect to the ethyleneimine unit in the... 

S. C. Crema, C. H. Kucera, C. Gousetis, and K. Oppenlaender. Cementing compositions containing polyethyleneimine phosphonate derivatives as ispersants. Patent EP 444542, 1991. 

McNeff, C., Zhao, Q., Almlof, E., Flickinger, N., and Carr, P. W., The efficient removal of endotoxins from insulin using quaternized polyethyleneimine-coated porous zirconia, Anal. Biochem., 274, 181, 1999. 

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