CHED 439 |
| We developed a laboratory activity appropriate for an introductory organic chemistry course. In this lab, students will conduct a ring-opening polymerization of lactide catalyzed/initiated by tin(II) ethyl hexanoate (Sn(Oct)2) and benzyl alcohol. The polymerization completes in approximately one hour. Percent conversion was determined by integration of the methine region of a 1H NMR spectrum, while Mn and Mw were determined by GPC. The stereochemistry of the polymerization can be demonstrated by having some of the students polymerize D,L-lactide and some polymerize L-lactide. The methine region of a 1H NMR spectrum of poly(D,L-lactide) is more complex than that of poly(L-lactide) because the chemical shifts of the methine protons depend on the configurations of nearby asymmetric centers. Additionally, the concepts of “green” chemistry can be introduced with this lab because polylactide is a biorenewable, biodegradable polymer. |
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Undergraduate Research Poster Session: Chemical Education
11:00 AM-1:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Chemical Education |