ERIC Number: EJ1161192
Record Type: Journal
Publication Date: 2017-Nov
Abstractor: As Provided
Using [superscript 1]H NMR Spectra of Polymers and Polymer Products to Illustrate Concepts in Organic Chemistry
Harrell, Mary L.; Bergbreiter, David E.
Journal of Chemical Education, v94 n11 p1668-1673 Nov 2017
The use of [superscript 1]H NMR spectroscopy to analyze the number-average molecular weight of a methoxy poly(ethylene glycol) (MPEG) and an acetate derivative of this MPEG is described. These analyses illustrate NMR principles associated with the chemical shift differences of protons in different environments, NMR integration, and the effect of the natural abundance of [superscript 13]C carbons in a polymer and the resulting low but predictable intensity of the satellite peaks due to [superscript 13]C-[superscript 1]H spin-spin coupling. Also included in this discussion is an example of end-group analysis of the product of an acetylation reaction. In the discussion of the acetylation product, an [superscript 1]H NMR spectrum of a crude product mixture where the small peaks due to end groups can be seen along with a set of impurities due to catalyst, solvents, and byproducts is included because, in practice, chemists often first see these sorts of spectra.
Descriptors: Spectroscopy, Organic Chemistry, Scientific Concepts, Concept Teaching, Molecular Structure, Scientific Principles, Teaching Methods, Undergraduate Study, Plastics
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: firstname.lastname@example.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Research
Education Level: Higher Education
Sponsor: National Science Foundation (NSF)
Authoring Institution: N/A
Grant or Contract Numbers: CHE1362735