ETHYLENE IMINE COPOLYMER

Glodde, M., Sirsi, S. R., Lutz, G. J. Physiochemical properties of low and high molecular weight poly(ethylene glycol)-grafted poly(ethylene imine) copolymers and their complexes with oligonucleotides. Biomacromolecules 2006, 7(1), 347-356. 

In contrast, similar examination of the product obtained by template polymerization of acrylic acid on poly(ethylene imine), using electrophoresis, leads to the conclusion that in this case graft copolymer is absent. 

Paper chromatography was also used to separate the complex obtained by polymerization of acrylic acid in the presence of poly(ethylene imine). In this case, both the complex obtained by mixing of two polymers and the complex obtained in template polymerization gave two distinct spots. No trace was found of any graft copolymer. 

Very often graft copolymers have been synthesized by the polyaddition of cyclic monomers, such as ethylene oxide, ethylene imine or caprolactam, to cellulose, proteins, polyamides, polyvinyl alcohol, etc. 

Griffiths PC, Alexander C, Nilmini R et al (2008) Physicochemical characterization of thermoresponsive poly(N-isopropylacrylamide)-poly(ethylene imine) graft copolymers. Biomacromolecules 9 1170-1178... 

The second way of forming nanoparticles of PE-surfs is to use water-soluble block-copolymers with one complexable (ionic) block and one non-com-plexable (nonionic) block. For example, the mesomorphous complexes (solid state) between poly(ethylene oxide)—b-poly(ethylene imine)s and dodecanoic acid can easily by dispersed in water to form nanoparticles [117]. The nanoparticles are of core-shell type and have sizes around 200 nm. Their cores are formed by poly( ethylene imine) dodecanoate while their shells consist of poly(ethylene oxide). It was found that the shapes of the nanoparticles depend on the PEI block. They are, for example, prolate if the PEI is linear and spherical if the PEI is branched. 

Fig. 6 Chemical structures of branched copolymers (x and y denote number averages of repeating units) a polyallylamine-gra/t-poly( /-methyl L-glutamate) (PAAx-g-PMLGluy, X = 175, y = 14), b poly(ethylene oxide)- Zoc/c-(branched-poly(ethylene imine)-gra/t-poly(y-benzyl L-glutamate)) (PEOx- -PEIy-g-PBLGlu2(o.4j+i) x = 113, y = 233, z = 0.2-2.9), and c poly(ethylene oxide)-MocA -([G-3]-dendritic poly(L-lysine)-acetal) (PEOx- -[G-3]-PALLys, x = 113, 227)...

It is possible to prepare block copolymers by free-radical initiation, as R. B. Seymour, G. A. Stahl, D. R. Owent, and H. Wood discuss in their chapter. Methyl methacrylate macroradicals were made with peroxide and azo initiators in diluents, and different vinyl monomers were polymerized onto them. Block copolymers of two ethylene imines, one having a long (lauroyl) side chain and one with a short (propionyl) side chain were synthesized by M. H. Litt and T. Matsuda in a two-step cationic polymerization process. Block and random copolymers of episulfides were prepared by E. Cernia, A. Roggero, A. Mazzei, and M. Bruzzone using anionic catalysts of metalated sulfoxides and sulfones. 

Copolymer complexes of mono- and dialkyl esters of itaconic acid modified by ethylene imines, with C0CI2 and CUCI2, have been obtained with the following structure [73,74]. 

Ethylene glycol dimethacrylate Ethylene imine Ethylene/magnesium acrylate copolymer... 

There are two major reasons for modification of pore surfaces in some polymeric resins (1) hydrophiiization of hydrophobic surfaces and (2) an increase in loading capacity and kinetics of ion-exchange resins. The former is typical of styrene-divinylbenzene copolymers that are too hydrophobic to be used directly for the separation of biopolymers in some modes. In this case, hydrophilic polymers such as dextran, poly(oxyethylene), poly(ethylene imine), and poly-(vinyl alcohol) are adsorbed and cross-linked on [35,43] or covalently linked to the pore surface to form a thin biopolymer friendly barrier on the hydrophobic surface. Regnier [44] was one of the first to develop a covalently attached hydrophilic coating that substantially decreased the nonspecific irreversible adsorption of proteins. 

Only a few polymers have be investigated so fer with respect to their usefiilness in these novel catalytic systems Pofy( 1-vinyl pyrrolidone), poly(vinyl alcohol) and some of their random copolymers, as well as poly(acry]ic acid), polyamides, and poly(ethylene imine). In the last three cases conq>lexation and no free metal formation has been reported. A wider variety of polymers thus still needs to be examined (7- ). 

Kojoh, S., Matsugi, T., Saito, J. etal. (2001) New monodisperse ethylene-propylene copolymers and a block copolymer created by a titanium complex having fluorine- containing phenoxy-imine chelate ligands. Chemistry Letters, 822-823. 

A PEG-PEl-PBLG hyperbranched block copolymer was prepared by amine-initiated NCA polymerization from the primary amine groups of poly(ethylene imine) (PEI), which had been coupled to a PEG chain via a diisocyanate. The hyperbranched block copolymers form micelles in aqueous solution with a large hydrophobic core and a cationic corona further stabilized by the PEG chains (see Fig. 21). The micelles can form complexes with DNA via electrostatic interaction, and enzymatic degradation of the micelles was shown in vitro. The copolymers therefore might be useful as new vectors for gene delivery [38]. 

Bannerjee, P., Weissleder, R., Bogdanov, A., Jr. Linear polyethylene-imine grafted to a hyperbranched poly(ethylene glycol)-like core a copolymer for gene delivery. Bioconjug. Chem. 2006, 77(1), 125-131. 

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