Session: 03-08-01: Micromechanics and Multiscale Modeling

Paper Number: 134323

134323 - Failure Prediction in Functionalized Cnt-Polymer Composite Materials Using Molecular Dynamics 

Deep space exploration missions require high-performance structural materials that are both lightweight and ultra-strong. CNT-based Polymer matrix composite (PMC) materials show exceptional specific strength and stiffness and can be tailored to meet the specific requirements of aerospace structural materials. PMCs show excellent material properties along the direction of CNTs or CNT structure materials such as CNT yarns, CNT socks, or CNT forests. However, the load transfer capability of these materials between reinforcement and matrix materials generally drives the interfacial strength. Functionalization of CNT surfaces with chemical groups has proven to improve the interfacial strengths of the PMCs. However, it is imperative to investigate the effects of the degree of functionalization on the structural integrity of the CNT materials. Moreover, crosslinks between the matrix polymer materials and functional groups provide additional media for load transfer. Molecular Dynamics (MD) is a computational tool that allows us to investigate the strength of materials at interfaces and quantify the effects of functional groups on the interfacial properties.

In this work, the aerospace-grade polymer bismaleimide (BMI)-CNT PMC model is developed using MD. CNT surface is functionalized with varying degrees of functionalization with the epoxide functional group and crosslinks are modeled between BMI and CNT at the sites of functionalization. Mechanical Testing is simulated to predict the maximum force the material withstands before the failure of covalent bonds between matrix and polymer. Primary results indicate that the CNT strength and integrity are compromised as we increase the degree of functionalization beyond optimum. The optimum number of crosslinks and the degree of functionalization of the CNT surface are predicted to maximize the load transfer capability.

Presenting Author: Swapnil Bamane Michigan Technological University

Presenting Author Biography: Swapnil started working as a Ph.D. student for CMMR LAB at Michigan Tech in the Fall of 2018 under the guidance of Dr. Gregory Odegard. He holds a B.E. degree in Mechanical Engineering from the University of Pune, India. He completed an MS degree in Mechanical Engineering (Design and Manufacturing) and an MS degree in Materials Science and Engineering at Michigan Technological University. His research is primarily based on molecular dynamics (MD) modeling of high-performance polymer resins for aerospace applications. As a PhD student, he was a part of NASA STRI: USCOMP and Process Modeling projects. During his Ph.D., he interned at Idaho National Laboratory for 8 months and performed research on MD modeling of rare earth elements for efficient separation. Currently, he is continuing his research on polymer-based composites at CMMR Laboratory as a post-doctoral researcher.