A high hydroxyl group content found in high molecular weight fractions of poly(oxyethylene glycol)
✍ Scribed by G. Delmas
- Publisher
- John Wiley and Sons
- Year
- 1968
- Tongue
- English
- Weight
- 649 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
The results of a fractionation of high molecular weight poly(oxyethy1ene glycol) with the mixture benzene-isooctane are presented. The fractions are characterized by gel permeation chromatography (GPC), infrared spectroscopy, viscometry, and dialysis. A high hydroxyl content was found for the higher fractions, which is not compatible with a linear polyoxyethylene glycol molecule with hydroxyl endgroups. The presence of hydroxyl groups on the chain is improbable. The dialysis of the higher fractions in CCld and toluene shows that a surprising amount passes through the dialysis bag. The possibility of degradation of the polymer is considered. However, GPC analysis of the products of the dialysis suggest that the high molecular weight is made up of aggregates of middle-sized molecules and low molecular weight ones, held together by hydrogen bonding between hydroxyl and ether groups. Some results of a fractionation in water with the lower critical solubility temperature a t 99°C. are given.