Polydispersity Analysis of Polyethylene Glycol by Gas and Liquid Chromatography

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 24 (2019) pp 30-34

Polydispersity Analysis of Polyethylene Glycol by Gas and Liquid Chromatography

Jessica Zagari and Markus M. Hoffmann*

Department of Chemistry and Biochemistry, The College at Brockport, State University of New York, Brockport, NY, 14420, mhoffman@brockport.edu
Received November 5, 2018. Accepted December 26, 2018.

Published: 18 January 2019

Abstract. Two variations of chromatography-based undergraduate analytical chemistry laboratory experiments for the characterization of synthetic polymers are presented, one employing gas chromatography and one employing liquid chromatography. Both experiments separate polydisperse polyethylene glycol (PEG) into their oligomer components to obtain a complete analysis of the mixture composition. The mole fraction distribution of the components is fitted to a Gaussian distribution function and the average molecular weight of the polydisperse PEG samples is obtained. In addition to learning instrument skills, the experiments reinforce basic concepts of the statistical analysis of experimental data and expose students to concepts relevant to the subject area of polymers. The latter was the main motivation to develop these experiments for the undergraduate laboratory curriculum in response to the 2015 American Chemical Society guidelines and evaluation procedures for Bachelor’s degree programs that call for specific coverage of content areas related to large-scale/complex materials including synthetic polymers.

Key Words: Laboratories and Demonstrations; analytical chemistry; ; gas chromatography; HPLC; polydispersity

(*) Corresponding author. (E-mail: mhoffman@brockport.edu )

Article in PDF format (271 KB) HTML format

Supporting Materials:

Details for interfacing the ELSD with a computer using Arduino hardware and free software; experiment handouts for the students providing background information and procedural and analysis detail; PEG 1000 analysis results, Microsoft Excel analysis file with completed GC chromatogram analysis. (1100 KB)