Comparison of (ArO)2TiClX (X = Cl, Cp) complexes in the living ring opening polymerization of caprolactone

POLY 126

Alexandru D. Asandei, asandei@ims.uconn.edu1, Liming Tang1, Gobinda Saha, gobinda@ims.uconn.edu1, Megan Gilbert1, Tracy A. Hanna, t.hanna@tcu.edu2, and Lihua Liu, l.liu@tcu.edu2. (1) Institute of Materials Science and Department of Chemistry, University of Connecticut, 97 North Eagleville Road, Storrs, CT 06269, (2) Department of Chemistry, Texas Christian University, 2800 S. University Drive, Fort Worth, TX 76129
The ring opening polymerization of caprolactone occurs readily at 90 °C in the presence of a series of Ti bisphenolates ((ArO)2TiClX, X = Cl, Cp) based on a substituted 2,2'-methylenebisphenoxo framework even in the absence of coinitiators or cocatalysts. The linear dependence of molecular weight on conversion, linear kinetics and low polydispersities (Mw/Mn ~ 1.1-1.2) indicate a living process in all cases. The phenoxide ligand substituents are not close enough sterically or electronically to the active Ti center to have a strong effect on the polymerization results. However, the stereoelectronic effects of the Cp ligand lead to a significantly slower polymerization by comparison with the parent CL complexes.
 

General Papers: Functional Materials
6:00 PM-8:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, August 20, 2007 BCEC -- Exhibit Hall - B2, Sci-Mix

Division of Polymer Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007