JCE Online Journal of Chemical Education
 | Subscriptions  | Software Orders  | Support  | Contributors  | Advertisers  | 

JCE Print

JCE Digital Library

JCE Software

Only@JCE Online

About JCE


  Home > JCE Print > Journal of Chemical Education > Issues > 2002  > January  >
In the Laboratory
Synthesis and Characterization of a Hyperbranched Copolymer
A. Timothy Royappa
Department of Chemistry, University of West Florida, Pensacola, FL 32514

Cover
January 2002
Vol. 79 No. 1
p. 81

Abstract
This experiment involves the cationic ring-opening copolymerization of glycidol (2,3-epoxy-1-propanol) with propylene oxide and is suitable for undergraduate polymer chemistry or advanced organic synthesis laboratory courses. Students are introduced to hyperbranched polymers and learn how to use a combination of analytical techniques in constructing a coherent picture of polymer structure. The reaction mechanism involves active participation by the hydroxyl functional group (of glycidol) in a cationic polymerization, from which protic species are usually, but not always, excluded. This critical feature, which is responsible for the extensive branching in the polymer, helps students learn the difference between the so-called "active chain end" and "activated monomer" propagation mechanisms. The short, straightforward synthesis, which uses commonly available laboratory equipment and commercially available chemicals, is carried out at room temperature and proceeds in high yield. GC monitoring of the reaction and NMR and FTIR analysis yield information about polymer structure and confirm chain branching. The stable polymer product is checked for solubility and further examined by gel permeation chromatography and differential scanning calorimetry, yielding results consonant with the structural information gained by spectroscopic means.
Supplement
A handout for students and notes for instructors are available.
*  Contents JCE2002p0081W.doc (Microsoft Word)
*  Download
JCE2002p0081W.pdf

JCE2002p0081W.zip

JCE2002p0081W.sit

More Information
*  Citation
Royappa, A. Timothy. J. Chem. Educ. 2002 79 81.
*  Keywords
Laboratory Instruction; Organic Synthesis; Polymer Chemistry
*  History
Created:
Last Updated:
December 3, 2001
March 16, 2005
  Home > JCE Print > Journal of Chemical Education > Issues > 2002  > January  > Page 81


Subscriptions

JCE HS CLIC

Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.


Contributions Welcome
JCE welcomes your submission

Advertisers
In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first.

Be An Ambassador
Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants.