Collaborative Research: Polar-Polyolefin Block Copolymers via MILRad Functionalization: A Platform for Amphiphilic Nanostructured Material Synthesis

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Eva Harth at the University of Houston and Professor Krzysztof Matyjaszewski at Carnegie Mellon University aim to explore the capabilities of generating anchor units in polymers of plastic materials during their synthesis and using these "plug-in" units as activators for further modification of the polymer. This two-step process will result in polymer chains that are composed of two segments (or blocks) of distinctly different structures and properties.

The unique polarity and solubility of each block allows the polymer to be used as "stitches" between two immiscible plastic materials or to form 3-D structures in shapes of spheres, worms and disks. The two research teams complement each other in their areas of expertise and are expected to work synergistically to establish chemical pathways to synthesize these diblock copolymers and study their special properties.

An automated continuous flow approach will be investigated to increase further the ease and practicability of diblock polymer preparation. The results of this research are expected to enhance knowledge in how to combine polar and non-polar chains to gain access to novel materials, and the accomplishments will be communicated to the public and scientific community.

This project will help to prepare a skilled workforce for the polymer industry by training graduate students and undergraduates, including students from underrepresented groups, in many aspects of polymer chemistry, organometallic chemistry and analysis.

Specifically, the two teams will collaborate to explore block copolymer and nanostructure synthesis based on new methods development, including a novel radical- and spin-trapping capability, to integrate olefin, acrylic and ethylene oxide segments into one polymeric architecture. The generation of macro-radicals through metal insertion/light-initiated radical polymerization as part of the polymerization pathway will be utilized to prepare intermediates to promote controlled radical polymerization via atom transfer radical polymerization and nitroxide-mediated polymerization.

This strategy may open up a new avenue for polar polyolefin di-block and triblock copolymers via chain extension and is expected to provide convenient access to block copolymers not yet available using existing methodology or only available via multi-step approaches. Polymerization-induced self-assembly processes and crystallization-driven self-assembly will be investigated as potential approaches to form nanostructures from di- and triblocks composed of polyolefins and polyacrylates.

Continuous flow chemistry will be used to optimize and scale up polyolefin macro-initiator synthesis and will be used in support of the synthesis of a diverse set of polyolefin-containing nanostructures.

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.