Development of User-Friendly Controlled Cationic Polymerizations Under Ambient Conditions

Cornell University, Ithaca NY

Investigators

Abstract

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Tristan Lambert of Cornell University will be developing a more user-friendly and versatile approach to make an important class of polymers. These polymers are formed from chemical reactions known as “living cationic polymerizations”, which have a broad array of potential applications for humanity. However, because of the very reactive nature of the intermediates in these polymerization reactions, they tend to be difficult to control and highly sensitive to impurities such as water. These drawbacks severely limit the materials that can be readily prepared by these chemistries and inhibit their use by non-specialists. Thus, the development of strategies that provide greater control and robustness for living cationic polymerizations represents a major challenge with wide ranging implications. This research program will develop such a strategy for cationic polymerizations using a novel class of polymerization agents called pentacarboxycyclopentadienes, or “PCCPs” for short. The PCCPs have unique properties that enable them to promote rapid yet controlled cationic polymerizations that protect against impurities like water, and thus make it straightforward to perform these reactions without special precautions. The PCCPs also aid in controlling the molecular structure of the polymer, and thus its macroscopic physical properties. The ability to conduct cationic polymerizations under user-friendly conditions—that is at room temperature and without rigorous avoidance of moisture or other impurities—will open up the use of these processes to non-specialists for use in a wide variety of applications. Professor Tristan Lambert of Cornell University will use pentacarboxycyclopentadienes (PCCP) initiators to develop user-friendly, controlled cationic polymerization reactions. The unique features of the PCCP system will enable these normally highly sensitive reactions to occur with greater control over polymer length, dispersity, and tacticity, and with greater robustness to ambient conditions than previously possible. The research will delineate the structural basis for this behavior and define the scope and capabilities of the PCCP system. In addition to this scientific effort, further educational outreach activities in terms of lectures to high school students and the development of a homeschool resource website will extend the impact of the proposed work beyond the scientific community to the general public. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.