Abstract

Abstract The thermal transitions in cholesteryl palmitate have been evaluated and compared to previously reported data. A sample synthesized from carefully purified cholesterol and palmitic acid using p-toluene sulfonic acid compared directly with previously reported data. A sample of recrystallized ester from a commercial source showed a slightly depressed solid to mesophase transition temperature. However, the mesophase proved to be smectic, commonly reported as monotropic with respect to the solid phase. Both smectic to cholesteric and cholesteric to isotropic liquid transitions were very sharp, indicating a very pure material. It is postulated that a specific impurity, an antioxidant, is responsible for this previously unreported effect. This effect of related compound interaction has been reported for nematic mesophase forming compounds. Thin layer chromatography, microscopy, depolarized light intensity analysis, differential scanning calorimetry and NMR spectroscopy data are discussed.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.