Atomistic simulation of thermal decomposition of crosslinked and non-crosslinked phenolic resin chains

Abstract

Carbon phenolic resin has been used as a charring ablative material in protecting the structure integrity of an object subjected to high heat loads, such as the re-entry vehicle. The composition of the pyrolysis gases generated from the charring ablator and injected into the surrounding boundary layer has a significant impact on the aerothermodynamics around the object. Recent studies revealed that the pyrolysis gas composition ejected from the charring ablator is sensitive to the incipient composition of the pyrolysis gases from material decomposition, which is not well known and thus leads to large uncertainties. We have explored the use of atomistic simulations to help understand the underlying chemistry involved in the thermal degradation of phenolic resins and determine the initial composition of the pyrolysis gases and their associated chemical evolution. In this study, reactive atomistic simulations were conducted to analyze the thermal decomposition of phenol monomers and non-crosslinked phenolic resin, as well as the propene oxidation. In addition, a numerical procedure for constructing chemically crosslinked phenolic resin based on molecular dynamics was explored and developed. The employed numerical procedures, obtained numerical results, and constructed crosslinked phenolic resin network are presented in this paper. Discussions and recommendation for future work are also included.