Graduate Seminar Series: "Photochemically and Thermally Triggered Covalent Adaptable Polymer Networks" by Dr. Christopher N. Bowman

Event Date: January 26, 2010
Speaker: Dr. Christopher N. Bowman
Speaker Affiliation: James and Catherine Patten Chair, Department of Chemical and Biological Engineering
and Department of Restorative Dentistry
University of Colorado-Boulder
Time: 3:30 - 4:30 p.m.
Location: FRNY G140
Polymer networks possessing reversible covalent crosslinks constitute a class of materials with unique capabilities including the capacity for adapting to an externally applied stimulus. These covalent adaptable networks (CANs) represent a paradigm in polymer network fabrication aimed at the rational design of structural materials possessing dynamic characteristics for specialty applications and functions. Here, we explore two distinct classes of CANs with either photochemically or thermally triggered responses. First, those in which the reversible bond formation is controlled by exposure to light will be discussed along with the subsequent initiation of the addition-fragmentation process that facilitates polymer network relaxation, photo induced actuation and shape memory effects, and stress relaxation. These results will be discussed in the context of thiol-ene-based photopolymerization reactions as well as their potential for implementation in thiol-yne photopolymerizations. Secondly, consideration of thermally inducible CANs will be presented; focusing on polymer networks formed from thermoreversible Diels-Alder adduct structures. In particular, the unique temperature dependent rheological behavior will be discussed as well as the potential for these materials to be healed through remotely controlled triggers that induce localized temperature changes. Ultimately, the potential for CANs-based materials to impact numerous materials applications will be presented in light of their distinctive array of material properties.

Professor Christopher N. Bowman received his B.S. and Ph.D. in Chemical Engineering from Purdue University in 1988 and 1991, respectively. After receiving his Ph.D., he began his academic career at the University of Colorado in January of 1992 as an Assistant Professor. Since that time Professor Bowman has built a program focused on the fundamentals and applications of crosslinked polymers formed via photopolymerization reactions. He works in the broad areas of the fundamentals of polymerization reaction engineering, polymer chemistry, crosslinked polymers, photopolymerizations and biomaterials. Professor Bowman has remained at Colorado throughout his academic career and is currently the Patten Endowed Chair of the Department of Chemical and Biological Engineering as well as a Clinical Professor of Restorative Dentistry at the University of Colorado at Denver. He serves as co-Director of the NSF/Industry Cooperative Research Center for Fundamentals and Applications of Photopolymerizations.