Poly ethylene imine , synthesis

Keywords Applications Cytotoxicity profile Gene delivery Hyperbranched polyamines Poly(amido amine) Poly(amido ester) Poly(ethylene imine) Polyglycerol amines Structure-property dependence Synthesis Transfection efficiency... 

Scheme I Synthesis of hyperbranched poly(ethylene imine) (PEI) via acid catalyzed ring-opening polymerization of aziridine. Each color represents a different branching unit blue for linear units (L), black for dendritic units (D), red for terminal units (T). PEI has a degree of branching (DB) of 62-73%, the depicted structure represents only a small idealized fragment. Reproduced with permission from [91]...

FIGURE 3.16 Monomer synthesis and cationic pol5mierization of oxazolines (Nu"=nucleophile, e.g., amine) followed by acid hydrolysis toward linear poly-(ethylene imine) for R=Me, Et. 

Besides hb poly(ethylene imine) (hbPEI) [vide infra), hb polyesters are a predominating class of hb polymers due to a straightforward synthesis and the success of the commercially available Boltom aliphatic polyesters. Pioneering work was conducted on hb copolyesters ranging from merely aliphatic, aliphatic-aromatic, to aromatic polyesters. Such materials are applied in coating or resins. Long et al. recently reviewed the field of branched polyesters with variation in the DB. ... 

Synthesis of PURs provided with lateral free functionalities, such as amino groups deriving from poly(ethylene imine) (PEI) or N-Boc serinol reagents. Such functionafities can be exploited for the grafting of peptides or natural polymers on the surface of the final device. Qiuang et al. (2009)... 

Poly(ethylene imine). Poly(ethylene amine) (PEI) is the simplest polybase. It can be prepared directly via the acid-catalyzed polymerization of ethyleneimine (aziridine, 24C) (Fig. 40). 24C may be prepared via a number of routes with ethanolamine being a convenient precursor (223). The cationic polymerization of 24C is very rapid due to the release of the ring strain associated with the monomer. However, the synthesis of PEI under these conditions leads to highly branched structnres dne to chain transfer reactions involving the —NH— species in the polymer backbone. Cyclic products can also be prodnced nnder these conditions. Copol5nnerization with an appropriate comonomer can rednce the degree of chain branching (224). 

A large step towards bio-functional nanotubes was taken by the same research group. An alumina membrane was first coated with two alternating layers of poly(ethylene imine) and poly(styrenesulfonic acid). Cytochrome c, with a positively charged surface at pH 7, was then alternated five times with poly(styrenesulfonic acid) in a LbL nanotube synthesis. Alternatively, cytochrome e and glutaraldehyde were employed to build up five covalent bilayers. Dissolution of the alumina template with 5% phosphoric acid yielded the protein-containing nanotubes. ... 

It has been proved that the basic polymers, which will be positively charged under acidic conditions, are also useful templates for the growth of calcium carbonate [243]. Hemispherical vaterite and needlelike aragonite can be selectively synthesized at the air/water interface by the mediation of poly(ethylene imines)(PEIs) dissolved in supersaturated calcium bicarbonate solution with different molecular weight of PEI blocks, suggesting that cationic polychains are also versatile templates for artificial material synthesis. 

Akijama, Y, Harada, A., Nagasaki, Y. and Kataoka, K. (2000) Synthesis of poly(ethylene gjycol)-block-poly(ethylene imine) possessing an acetal group at the PEG end. Macromolecules, 33, 5841-5845. 

In figures 3, 4, and 5, commercial synthesis of poly(ethylene imine), polyvinylamine, and polyvinylalcohol amine are described (6,7). 

Figure 3 Synthesis of Poly (ethylene imine), primary secondary tertiary Nitrogen ratio 1 1 0.75...

Poly(ethylene glycol) supported liquid-phase syntheses by both the reaction of (polyethylene glycol (PEG))-supported imines with nitrile oxides, generated in situ from aldoximes, (300) and 1,3-dipolar cycloadditions of nitrile oxide, generated in situ on soluble polymers with a variety of imines (301, 302) have been described. The solid-phase synthesis of 1,2,4-oxadiazolines via cycloaddition of nitrile oxide generated in situ on solid support with imines has also been elaborated (303). These syntheses of 1,2,4-oxadiazolines provide a library of 1,2,4-oxadiazolines in good yields and purity. 

Novel magnetic iron oxide nanoparticles coated with polyfethylene imine)-g-poly(ethylene glycol) for potental biomedical application Synthesis, stability, cytotoxicity and MR imaging. International Journal of Pharmaceutics, Volume 408, Issues 1-2,15,p>p 130-137. 

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