Poly ethylene glycol advantage

Often poly(ethylene glycol)s or derivatives thereof can be used instead of crowns or onium salts advantageously, although their catalytic activity frequently tends to be somewhat lower. The possible toxicity of crowns and cryptands and the price difference between these compounds and onium salts (100 1 to 10 1) are other important factors to be considered. Thus (1) [17455-13-9] (2) [14187-32-7] and (3) [16069-36-6] and cryptands are used more often in laboratory work, whereas onium salts are more important for industrial processes. 

Incorporation of Poly(Ethylene Glycol) Lipid into Lipoplexes On-Line Incorporation Assessment and Pharmacokinetics Advantages... 

Though CPE has many advantages [10], some problems remain to be solved such as (1) limited number of surfactants, (2) high cloud-point, and (3) strong hydrophobic nature. In an attempt to overcome some of these limitations, Tani et al. [281] proposed a new method that involves solubilization of hydrophobic membrane proteins into aqueous micellar solutions of alkylglucosides, followed by phase separation induced by the addition of a water-soluble polymer such as poly(ethylene)glycol (PEG) and dextran T-500. Using this approach they could carry out the whole procedure from solubilization to phase separation at 0 °C. 

An extension of the combinatorial synthesis in solution is achieved by the use of soluble polymeric supports [80, 81], which combines some of the advantages of chemistry in solution and on solid phase. The so-called liquid-phase combinatorial synthesis is based on the physical properties of poly (ethylene glycol) monomethyl ether. The polymer is soluble in a variety of aqueous and organic solvents, which allows reactions to be conducted in homogeneous phase whereas the propensity to crystallize in appropriate solvents facilitates the isolation and purification of the compound at each step of the combinatorial synthesis. 

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