9520803 Wagener The viability of acyclic diene metathesis (ADMET) polymerization has been demonstrated during the most recent funding period by identifying the functionalities which can be tolerated during this condensation reaction. This new chemistry has led to telechelic hydrocarbon polymers synthesized by depolymerization reactions, as well as to many advanced polymer systems. This grant addresses four generally related research areas which expand upon what has been done thus far with ADMET polymerization. The chemistry of conjugated dienes will be explored. Hydrocarbon conjugated dienes will be examined fipst followed by expansion to aromatic conjugated dienes. The mechanistic enigma associated with terminal aliphatic dienes will be elucidated. Further, the catalyst base for ADMET chemistry will be expanded to include considerably less expensive systems, and speed of these reactions (the kinetics) will be elucidated in such detail that the practical application of these results will be well understood. Thermoreversible network polymers will be made with the goal of improving the recyclability of waste plastics systems, and finally, chiral polymers will be prepared to broaden the utility of this new chemistry. %%% Interest in the commercial utility of ADMET chemistry is high, as judged by the response from American industry during the past three years of NSF support. Particularly significant are applications to the synthesis of specialty polymers, the preparation (via depolymerization) of targeted molecules of high commercial value, and the utility of ADMET chemistry in the reuse of well known commercial polymers, such as polybutadiene. This renewal builds upon all of these opportunities. ***
