Establishing Physical and Chemical Mechanisms of Polymerization and Pyrolysis of Phenolic Resins for Carbon-Carbon Composites

The complex structural and chemical changes that occur during polymerization and pyrolysis critically affect material properties but are difficult to characterize in situ. This work presents a novel, experimentally validated methodology for modeling the complete polymerization and pyrolysis processe...

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Bibliographic Details
Main Authors: Ivan Gallegos, Josh Kemppainen, Jacob R. Gissinger, Malgorzata Kowalik, Adri van Duin, Kristopher E. Wise, S. Gowtham, Gregory M. Odegard
Format: Article
Language:English
Published: Elsevier 2023-09-01
Series:Carbon Trends
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Online Access:http://www.sciencedirect.com/science/article/pii/S2667056923000457
Description
Summary:The complex structural and chemical changes that occur during polymerization and pyrolysis critically affect material properties but are difficult to characterize in situ. This work presents a novel, experimentally validated methodology for modeling the complete polymerization and pyrolysis processes for phenolic resin using reactive molecular dynamics. The polymerization simulations produced polymerized structures with mass densities of 1.24 ± 0.01 g/cm3 and Young's moduli of 3.50 ± 0.64 GPa, which are in good agreement with experimental values. The structural properties of the subsequently pyrolyzed structures were also found to be in good agreement with experimental X-ray data for the phenolic-derived carbon matrices, with interplanar spacings of 3.81 ± 0.06 Å and crystallite heights of 10.94 ± 0.37 Å. The mass densities of the pyrolyzed models, 2.01 ± 0.03 g/cm3, correspond to skeletal density values, where the volume of pores is excluded in density calculations for the phenolic resin-based pyrolyzed samples. Young's moduli are underpredicted at 122.36 ± 16.48 GPa relative to experimental values of 146 – 256 GPa for nanoscale amorphous carbon samples.
ISSN:2667-0569