Lecture Andreas F.M. Kilbinger
|13 September 2012||FWN-Building 5113.0202, Nijenborgh 4, 9747 AG, Groningen|
|Speaker:||Prof. Dr. Andreas F.M. Kilbinger|
|Affiliation:||University of Fribourg, Department of Chemistry, Switzerland|
|Title:||Synthetic methods or chain end functionalization in ROMP|
|Date:||Thu Sep 13, 2012|
|Telephone:||+31 50 464 6318|
In this presentation a review of our recent results for end-functionalizing ruthenium carbene initiated living ring opening metathesis polymerization (ROMP) polymers will be presented. Polymers carrying particular functional groups only at the chain-ends are very interesting for a variety of industrial and academic applications. Polymeric surfactants and polymer-protein conjugates are two examples for the former and polymer-beta-sheet-peptide conjugates one example for the latter. The functionalization of macroscopic or nanoscopic surfaces often relies on mono-end functional polymers. Complex macromolecular architectures are often constructed from macromolecules carrying exactly one functional group at their chain-end. The ring opening metathesis polymerization is particularly interesting in this context as it is one of the most functional group tolerant polymerization methods known. Additionally, high molecular weight polymers are readily accessible with this technique, a feature that living radical polymerizations often struggle to achieve. Finding new ways of functionalizing the polymer chain-end of ROMP polymers has therefore been a task long overdue.
The general problem in end-functionalizing living ROMP polymers arises out of the high functional group tolerance of the propagating ruthenium alkylidene complexes. This functional group tolerance significantly reduced the number of functional terminating agents that can be employed to introduce functional groups at the polymer chain end.
Over the last years we have developed several synthetic methods that allow the precise end-functionalization of such polymers with end-groups such as alcohols, aldehydes, carboxylic acids, thiols, or amines. These functional end groups were typically introduced using one of two synthetic approaches, the sacrificial block copolymer synthesis or the vinyl lactone quenching.
Both approaches will be reviewed in the presentation. Additionally, we will present some "kinetic tricks" that significantly simplify the synthetic effort needed to prepare end-functional living ROMP polymers.
|Last modified:||22 October 2012 2.31 p.m.|