Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
Session: 4
Room: Exhibit Hall
Jeremiah McGee - Southern University and A&M College
Co-Author(s): Dr. Congyuan Zheng, Southern University and A&M College; Dr. Patrick Mensah, Southern University and A&M College; Ama Amponsah, Southern University and A&M College
Sandwich structures have piqued the interest of the transportation and automotiveindustries due to their relatively high specific strength, ease of fabrication, and high specificstiffness. Despite these attractive properties, they are prone to damages such as matrix crackingand debonding of the skin/core interface resulting from low-velocity impact events, and theseaffects their structural integrity and performance. Self-healing of these structural damages has beenproposed and studied to prolong the lifespan and maintain the integrity of sandwich panels.However, the conventional self-healing approaches become challenging in situations where wider-opened end cracks are present. Thus, shape memory polymers (SMPs), which are smart materials,have been designed to close wider-opened end cracks via a close-then-heal (CTH) strategy, i.e., awider opened crack will be first narrowed by the constrained recovery of the programmed SMPmatrix and then followed by either extrinsic or intrinsic healing. Herein, the mechanical behaviorand shape memory effect of an epoxy-based shape memory polymer (vitrimer) will be evaluatedto determine its potential as a core material for sandwich structures. The vitrimer will besynthesized by mixing branched polyethylenimine (PEI) and diglycidyl 1,2-cyclohexanedicarboxylate (DCN) in a ratio of 1:2. The thermal properties of the vitrimer will bestudied using Differential Scanning Calorimetry (DSC). The mechanical behavior of the SMP willbe examined via a uniaxial compression test at both room temperature and above its glass transitiontemperature (Tg). Furthermore, the shape memory effect of the SMP will be evaluated via athermomechanical programming cycle using its shape fixity and shape recovery ratio. Hence,results from the thermomechanical tests will determine the suitability of using PEI-DCN shapememory polymer as core material for sandwich structures.
Funder Acknowledgement(s): CREST REU
Faculty Advisor: Ama Amponsah, ama.amponsah@sus.edu
Role: The mechanical behavior on shape memory polymers and how their recovery rate varies at different temperatures and ratios.