CLIMA/Collaborative Research: Discovery of Covalent Adaptable Networks for Sustainable Manufacturing and Recycling of Wind Turbine Blades

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

The continued growth of wind energy in the renewable energy landscape is key to the mitigation of climate change. However, this requires the construction of large-scale energy infrastructure that can be energy- and cost-intensive during manufacturing and decommissioning. In particular, there are critical sustainability challenges in the manufacturing and recycling of wind turbine blades. These challenges originate from the permanent nature of the fiber-reinforced thermoset polymer composites that underlie the structure of wind turbine blades. This CiviL Infrastructure research for climate change Mitigation and Adaptation (CLIMA) award supports fundamental research that accelerates the discovery of a new family of polymers, Covalent Adaptable Networks (CANs), and their composites that are mechanically strong yet reversible to enable recycling, repairing, and reprocessing. Knowledge to be obtained from this project facilitates cost-effective manufacturing and recycling of wind turbine blades, thereby improving the competitiveness and sustainability of wind energy in the global clean energy landscape and augmenting U.S. industry and economy. Additionally, this project supports outreach activities to engage researchers in national laboratories and the wind energy industry, educate K-12 students in composites, organic materials, computer-aided design and clean energy, recruit undergraduate researchers especially underrepresented groups, and enrich curricula through guest lectures. Covalent Adaptable Networks (CANs) are polymers crosslinked by covalent bonds that become reversible upon heating or other external stimuli. They combine the structural stability of thermosets and the malleability of thermoplastics. This project aims to establish a systematic research framework to discover new CANs and their composites to meet the multi-faceted requirements of material properties posed by the manufacturing, operation, and recycling of wind turbine blades. The research features an interdisciplinary collaboration among mechanics, materials, and manufacturing, and includes three components: molecular design, organic material synthesis, and mechanics of the new polymers. For molecular design, a cyber-platform combining machine learning and molecular dynamics (MD) simulations is created to generate candidate monomers of CANs. The synthesis component establishes a feasible molecular design space and allows CAN polymers to be synthesized from candidate monomers for manufacturing and testing. The mechanics component focuses on testing and modeling the mechanical behavior of the CAN polymers. The three components are integrated by preparing coupon-scale CAN composite samples and benchmarking their mechanical properties against the thermoset composites currently used in wind turbine blades. Manufacturing and recycling processes such as vacuum bag molding, thermoforming, lamination and chemical dissolution of CAN composites and the effects of processing conditions are also investigated. This project is supported jointly by the Mechanics of Materials and Structures (MoMS) and the Advanced Manufacturing (AM) programs of the Civil, Mechanical and Manufacturing Innovation (CMMI) Division in the Directorate for Engineering. 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.