Session: 16-01-01: Government Agency Student Poster Competition

Paper Number: 150102

150102 - Optimizing the Self-Healing Parameters of Dcn-Pei Vitrimer Through Welding and Lap Shear Testing 

One of the more promising recent developments in the field of polymer science has been the creation of self-healing materials, as they are applicable to industries where durability and maintenance are paramount. Owing to their dynamic covalent bond network, DCN-PEI vitrimers have very special self-healing properties with excellent mechanical performance, making them an attractive matrix component in composite materials. Reviewed herein is the optimization of the self-healing parameters of DCN-PEI vitrimers. First, determination of the self-healing behavior of the pure matrix material needs to be performed before studying the healing dynamics at the matrix-fiber interface. The optimum conditions in regard to time, temperature, and pressure that needs to be applied to ensure maximum strength and durability for the healed joints need to be found.

A systematic variation in the healing parameters is done, followed by evaluation through testing the strength of the welded joint with lap shear tests. Samples of DCN-PEI vitrimers are prepared and subjected to controlled damage. Then, healing is initiated under conditions of time, temperature, and pressure that would allow the most effective combination to be singled out. Lap shear tests, measuring the force applied to break the healed joints, reach quantitative data on each set of parameters for effectiveness. These tests would be vital in establishing the shear strength of the healed material relative to its native shear strength that is approximately 35 MPa.

Preliminary results indicate that there is a critical regime of temperatures and pressures beyond which the efficiency of self-healing increases enormously. These include physical conditions, such as temperatures just above Topology freezing Transition, that allow the formation of dynamic covalent bonds again without degrading the material. Another critical factor is the healing time; this is because long enough time is required for the reformation of bonds, while too long times may turn out to be practically inefficient in industry. Applied pressure during healing ensures an intimate contact between the damaged surfaces that promotes effective bond exchange reactions.

The associated implications with these results are huge for the application of DCN-PEI vitrimers within composite materials. Knowing the most appropriate self-healing parameters of the pure matrix material will create a foundational basis for effective design or further investigations on healing dynamics at the matrix-fiber interface. Such knowledge enables developing stronger, tougher composite materials able to self-heal after damage, reducing maintenance costs and extending component life under high-stress applications such as aerospace, automotive, and electronics.

It is expected that the optimization parameters of self-healing in DCN-PEI vitrimers will also be overdue for their application in advanced composite materials. On this front, the work presented herein provides valuable insight into the process of healing in the pure matrix material, thus opening the door further for research and innovation in the field of self-healing composites.

Presenting Author: Bernard Mahoney Southern University and A&M College

Presenting Author Biography: Bernard Mahoney is a graduate student of Southern University and A&M College, Baton Rouge Louisiana. He is presently pursuing a Masters degree in Mechanical engineering. He holds research interests in areas of advanced composite materials, materials science and machine design. He is driven by a passion for innovation and a commitment to enhancing material performance and durability. Bernard aspires to translate this academic expertise into a successful career in industry, where they can contribute to cutting-edge advancements and practical applications in engineering. His dedication to both academic excellence and practical solutions positions him as a promising professional in the field of mechanical engineering.

Authors:

Bernard Mahoney Southern University and A&M College
Patrick Mensah Southern University and A&M College
Guoqiang Li Louisiana State University