Simulating the Pyrolysis of Phenolic Resin Using Reactive Molecular Dynamics

Ivan Gallegos, Michigan Technological University
Josh Kemppainen, Michigan Technological University
Jacob R. Gissinger, NASA Langley Research Center
Kristopher E. Wise, NASA Langley Research Center
Margaret Kowalik, Pennsylvania State University
Gregory M. Odegard, Michigan Technological University

Abstract

Phenolic resin is a thermosetting polymer that has historically been used as a carbon matrix precursor for carbon-carbon composite manufacturing due to its relatively high char yield. However, the complex structural and chemical changes occurring during pyrolysis are difficult to characterize in situ. This work presents a novel method for modeling the pyrolysis processes for a polymerized phenolic resin using reactive molecular dynamics. The characteristics of the pyrolyzed model structures agree with experimental X-ray diffraction studies on glassy carbon matrices, with interplanar spacings of 3.80 ± 0.06 Å and crystallite heights of 10.98 ± 0.35 Å. The resulting structures are free of defects, and the mass densities of 2.01 ± 0.03 g/cm3 and Young's moduli of 123.29 ± 22 GPa are found to be in reasonable agreement when compared to skeletal mass densities of glassy carbon and Young's moduli of nanoscale glassy carbon thin films, respectively.