Poly(ethylene glycol) or Poly(ethylene oxide)?: Magnitude of end-group Contribution to the Partitioning of Ethylene Oxide Oligomers and Polymers between Water and Organic Phases

Abstract

A partição de PEO de água para CH 2 Cl 2 e CHCl 3 aumenta com a sua massa molar, até se tornar constante em torno de 3 000 g mol -1 . Estes resultados revelam que a partição de PEO é bastante sensível à contribuição dos grupos hidroxila, sugerindo a transição de caráter poliglicol para poliéter em torno de 3000 g mol -1 .PEO partitioning from water to CH 2 Cl 2 and CHCl 3 increases with its molar mass, leveling off at ca. 3 000 g mol -1 . Such a behaviour is related to PEO end-group contributions, suggesting a polyglycol to polyether transition at ca. 3 000 g mol -1 .

Effect of molecular weight and end-group nature on the solubility of ethylene oxide oligomers in 2H, 3H-decafluoropentane and its fully fluorinated analogue, perfluoropentane

“…Although the amount of PFP that can be incorporated before phase separation occurred increased with the end-group methylation, the range of PFP amount within which the cloud-point drop was observed is much narrower as methlylation was increased. Such early precipitation of the polymer observed upon the addition a non-co-solvent is a method already used in polymer fractionation (da Silva & Loh 1998; Spitzer et al 2002b). This mixed solvents study clearly shows that hydrogen bonding between the solvent and the solute, in competition with the end-group interactions, is the driving force behind the solubility of PEG oligomers in these fluorinated liquids of interest.…”

Upgrading of bio‐separation and bioanalysis using synthetic polymers: Molecularly imprinted polymers (MIPs), cryogels, stimuli‐responsive polymers

“…PEO is synthesized from ethylene oxide monomers. PEO has a hydroxyl group [ 36 ]. PEG has a lower molecular weight than PEO.…”

Stabilizing Colloidal Particles against Salting-out by Shortening Surface Grafts

“…Ito et al [32] found that high-MW PEG had the same affinity for the interface between toluene and water, regardless of in which phase the PEG was initially dispersed. The end group and the MW of PEG both affect the surface activity [33], at least for a MW below 3000 g/mol, above which the type of end group becomes less important. Having methyl-terminated PEG, in contrast to the more commonly hydroxyl-termination, increases the hydrophobicity due to less opportunities for hydrogen bonds with the water molecules [33,34].…”

“…The end group and the MW of PEG both affect the surface activity [33], at least for a MW below 3000 g/mol, above which the type of end group becomes less important. Having methyl-terminated PEG, in contrast to the more commonly hydroxyl-termination, increases the hydrophobicity due to less opportunities for hydrogen bonds with the water molecules [33,34]. It is noticeable that the end group for low-MW PEG becomes more important when the solvent quality is decreased [34].…”