Analytical pyrolysis gas chromatography/mass spectrometry (py-GC/MS) of poly(ether urethane)s, poly(ether urea)s and poly(ether urethane-urea)s

High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid of an instrument data processor. Highly accurate mass spectral data enabled the calculation of higher...

Ionomycin, a new polyether antibiotic.

Ionomycin, a new polyether antibiotic with a high affinity for calcium ions, is obtained in pure form from fermentation broths of Streptomyces conglobatus sp. nov. Trejo by solvent extraction. It is unique amongst known polyether antibiotics in that it has a UV absorption maximum at 300 nm. thereby distinguishing it from other antibiotics of its class. The Ca salt has the molecular formula C41H...

Desorption Kinetics of Polyether Lubricants from Surfaces

Desorption or evaporation is one of the mechanisms for loss of perfluoropolyalkylether (PFPE) lubricants from the surfaces of data storage media. One approach to minimizing PFPE loss to desorption is the use of lubricants with increasing molecular weight or increasing average chain length. In order to understand the effects of chain length on the lubricant evaporation kinetics we have studied t...

Isolation of a new polyether antibiotic, lonomycin.

A new polyether antibiotic, lonomycin, was isolated from the culture of Streptomyces ribosidifcus strain TM-481. The antibiotic obtained as a sodium salt is a colorless prism having a molecular formula of C44H75O14Na(M.W. 850), m.p. 188 approximately 189 degrees C, and has no absorption maxima in the ultraviolet region. The infrared and NMR spectra of the antibiotic suggest the presence of a ca...

Effect of moisture on polyether impression materials.