PREPARATION AND CHARACTERIZATION OF PURE OLIGO(ETHYLENE GLYCOL)S .2.

A pure sample of an oligo(ethylene glycol) (OEG), tetrapentaconta(ethylene glycol) (HO(CH2CH2O)54H (OEG54)), has been prepared by stepwise synthesis coupled with preparative size exclusion chromatography (SEC) used as a separation method. The purity of the OEG54 sample has been checked by analytical SEC and differential scanning calorimetry. Furthermore, the molecular weights (MW) of the OEG54 sample and a pure sample of octadeca(ethylene glycol) (OEG18) previously prepared have been determined by mass spectroscopy, light scattering (LS), vapor pressure osmometry, C-13 NMR, and H-1 NMR. The observed MW values of the OEG samples are in good agreement with those expected from their chemical formulas. In particular, fairly good agreements observed in LS and H-1 NMR measurements show that these pure OEG samples can be used as ideal MW standard samples.