A Theoretical-Experimental Investigation of Multi-Scale Mechanisms of Toughness Enhancement in PEKK/Nanographene Composites for Navy Applications
Abstract
Enhancing the stiffness, toughness and damage tolerance of materials and structures while minimizing their weight and cost are key considerations in the development of new and novel structural concepts. In the past two decades it has been shown that enhancing such properties for monolithic materials is feasible with the judicious insertion of heterogeneous nanoscale phases as fillers in traditional structural materials, which modify one or more fundamental mechanisms of mechanical deformation. With this background in mind, the primary objective of this proposal is to develop a fundamental understanding of interfacial and length-scale based damage mechanisms at the microscale in order to significantly improve the macroscale fracture toughness of thermoplastic polymer matrix composites (TPMC) by the insertion of 2-D nanofillers. A synergistic two-pronged theoretical-experimental approach is proposed to develop anovel fracture-mechanics based framework by exploiting the underlying physical deformation and damage evolution processes at the microscale in order to improve the fracture toughness of thermoplastic polymers and their composites through crack-tip shielding with the aid of graphene nanoplatelet (GNP) fillers. The proposed approach is analogous to #fighting fire with fire#, because we are utilizing controlled damage in the fracture process zone (FPZ) at the microscale through targeted debonding of nanoparticles to mitigatecrack initiation at the macroscale through crack-tip shielding in the near-tip FPZ. In the proposed study, the number density of GNPs and their size serve as the primary control parameters for improving fracture toughness. A detailed molecular dynamics study of the validity of this concept is proposed, as well as experimental verification. Crack initiation as well as crack propagation toughness enhancements in PEKK thermoplastic resin will be investigated in this study. The PEKK thermoplastic resin will be supplied to the PI by Arkema Inc.The proposed work will be performed by PI Dr. Samit Roy at the University of Alabama (UA), with researchers at Arkema Inc., Mr. Robert Barsotti and Mr. Javier Lazo, providing valuable technical advice.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 11, 2024
- Source ID
- N000142412179
Entities
People
- Samit Roy
Organizations
- Office of Naval Research
- United States Navy
- University of Alabama