Computational chemistry studies of phenolic resin

Abstract

Different computational techniques have been used to study phenolic resins with the objective of developing methods for predicting the high temperature physics and chemistry of resins with sufficient accuracy to produce data for the engineering modelling codes used to design thermal protection systems. The building of structural models of the resin using MOPAC ® and the validation of these models through comparison of measured and calculated thermochemical, structural and spectroscopic properties is described. Using these structural models, high temperature resin chemistry is simulated using the reactive molecular dynamics programme ReaxFF. Preliminary results are presented for early stage gas evolution and final stage char production during pyrolysis.

Comparison of ReaxFF, DFTB, and DFT for Phenolic Pyrolysis. 1. Molecular Dynamics Simulations

“…Molecular dynamics (MD) simulations offer another route toward understanding the detailed chemistry of phenolic pyrolysis. Recently, the reactive force field ReaxFF has been used for MD simulations of phenolic pyrolysis. ,− Jiang et al simulated the initial stage of pyrolysis . They found that H 2 O is the first reaction product observed when temperatures reach approximately 2900 K. This is followed by H 2 and C 2 H 2 and finally by CO.…”

“…Improving the performance of ablative materials will require understanding the gaseous product distribution, increasing the char yield, and producing char with improved properties, such as superior mechanical strength to prevent spallation of the surface char layers. For these purposes, it is important to obtain a fundamental understanding of phenolic pyrolysis reaction mechanisms, the process of char formation, and the resulting structural, mechanical, and thermal properties of char. − …”