GOALI: CAS: Targeted Design of Blocky Poly(Ether Ether Ketone) Copolymers for Enhanced Interfacial Interactions in Blends and Composites

NON-TECHNICAL SUMMARY:

The current demand for enhanced material properties has often followed a bottom-up approach to synthesize new polymers using complex chemical procedures that generally just expands that vast array of long-lasting plastics in the environment. A more sustainable approach is to use existing materials in new ways. For example, the high cost of poly(ether ether ketone) (PEEK) and its inherent stability strongly favor end-of-use recycling and/or upcycling as opposed to landfilling.

In this project, the widely valued approach of compatibilizing polymers in blends to address the critical economic and environmental sustainability needs of our society will be accomplished by performing simple chemical modifications on existing feedstocks of PEEK. Specifically, a new physical approach will be used to create blocky copolymers that are known to be beneficial in polymer blends by selectively modifying specific sequences of units along the chains of commercially available polymers.

The blocky PEEK polymers will be targeted toward new blends of PEEK with other valuable polymers as a means to eliminate waste and upcycle PEEK to new materials with synergistic enhancements in properties. These same polymers will also be used to facilitate strong bonds between PEEK and solid fillers in the formation of new composites with enhanced mechanical properties.

With respect to the grand challenges facing our society, this project will provide cost-effective, environmentally friendly, readily available materials alternatives needed to meet critical demands for advanced materials in a wide range of commercially relevant technologies. The nature of research activities in this project, involving close collaboration between academic and industrial laboratories, will provide broadly interdisciplinary training to a diverse community of researchers and students, including underrepresented groups.

TECHNICAL SUMMARY

The widespread commercial application of block copolymers as blend compatibilizers and fiber sizings is limited by the expensive and rigorous polymerization methods needed to control the sequence of comonomers in the form of discrete blocks. As a transformative approach, the PIs propose a facile, physical polymer chemistry alternative to yield controlled blocky microstructures in poly(ether ether ketone) (PEEK) via post-polymerization functionalizations in a heterogeneous, semi-crystalline, gel state.

The fundamental focus of this project will be on pushing the limits of blockiness that is achievable with this new process, expanding the synthetic toolbox of functionalization chemistries for targeted interfacial interactions/reactions, and understanding the molecular-level impact of blocky functionalization on phase behavior and interfacial interactions in high-performance polymer blends and composites. This academic-industrial collaboration is poised to address the grand challenge of forming interfacially active copolymers for PEEK-based blends and composites, with compatibilization efficiencies rivaling that observed with conventional segmented block copolymers.

The overall fundamental goal of this project is to understand the role of the compatibilizer microstructure (blocky vs. random) on interfacial properties in multiphase systems. The interdisciplinary nature of research activities in this project, ranging from pure chemistry, materials recyclability, to macromolecular engineering, will provide a plethora of educational opportunities to a diverse community of citizens and researchers eager to contribute to our nation’s leadership in ensuring a healthier, more sustainable global society.

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.