Towards Light-Weight Composites for Defense Applications: Engineering Structure Dynamics and Rheological Properties of Functional Inks
Abstract
The aim of the FAMU proposal is to utilize extrusion-based Additive Manufacturing (AM) to produce interfacially enhanced thermoset resin-filler composites with increased toughness, but at higher loading levels that are well above the reported percolation thresholds. In recent years AM of thermosetting resins has gained substantial attention starting with research carried out at the Air Force Research Labs (AFRL) on high temperature thermosetting resins with in-line XPCS studies. Other agencies like Navy, Oak Ridge National Labs (ORNL) and companies such as Boeing have increased their efforts in large scale AM, starting with moderate temperature epoxy resins. Room temperature liquid resin systems will be a key processing route towards polymer matrix composite manufacturing, however, there are still issues with lack of interfacial morphology with reinforcement fillers resulting in lack of toughness in printed parts. In order to gain a fundamental understanding of how to engineer toughness in composites Ð it is critical to study the resin-filler interactions especially the mechanisms at much smaller length scales (~ 10-100nm of the size of the filler). By monitoring the structure, dynamics and rheology of the system which are directly influenced by the interactions, a microscopic model can be developed to predict macroscopic properties. The idea is to use self-assembly of the filler particles in the resin matrix to create fibrillar structures that can be aligned into continuous fibers for composite reinforcement during AM. We will further undertake a fundamental study using the above mentioned in-line techniques in which we carefully characterize the mechanisms of resin-filler interactions at smaller length scales and high loading to gain understanding of the structure-function relationships. There are three main aims in the work Ð 1) Characterization of the effect of particle shape and surface chemistry on resultant structure, and dynamics of the functional inks; 2) Effect of shear on structure-dynamics-function relationships; and 3) To understand the influence of particle functionalization and self-assembly on toughness of resultant cured composite. Intellectual Merit: By systematically investigating the mechanisms of self-assembly and the structure and dynamics at small length scales, we will get a fundamental and microscopic understanding of structure-dynamics-function relationships in materials of interest to the DOD. As a result, the work will potentially lead to novel design rules that can aid a broad range of technologies. The work is in-line with the mission of DOD and collaborations are in place to work with Dr. Hilmar Koerner at AFRL who will play a key role. An educational partnership agreement is already in place with AFRL and the work will be greatly aided by a recent DOD DURIP award and recently awarded research instrumentation grant through the DOD HBCU/MI program. FAMU will utilize its dedicated AM center to carryout fundamental science studies. Impact on FAMU: 1) The project will play a key role in the education of post-doctoral students, minority graduate and undergraduate students in the area of materials and expose them to state-ofthe- art research. 2) Collaborations with AFRL will strengthen the research program at FAMU and enable the team to participate more competitively in defense research programs. 3) Internship program in collaboration with AFRL will enhance the education of minority students Ð in line with the mission of DOD. 4) Coupled with the NSF CREST CENTER grant (which will support graduate students & internships) the proposal will emphasize core research infrastructure at FAMU to become a world leader of additive manufacturing technology. FAMU is the only HBCU in the whole country to offer a PhD in chemical engineering and industrial engineering.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 31, 2020
- Source ID
- W911NF2010263
Entities
People
- Subramanian Ramakrishnan
Organizations
- Army Contracting Command
- Florida A&M University
- Office of the Secretary of Defense