Reactive force-field MD simulation on the pyrolysis process of phenolic with various cross-linked and branched structures

Abstract

Based on the reactive force-field (ReaxFF) molecular dynamics, the thermostability of cross-linked and non-cross-linked phenolic was compared to study the effect of cross-linked and branched structures on the pyrolysis mechanism. The results show that during the pyrolysis process, phenolic tends to break into low-boiling molecules with less than 4 carbon atoms and polymerizes into macromolecules with more than 1500 carbon atoms. The results of residual carbon rate and products distribution confirm that carbon skeleton of phenolic resin with high degree of crosslinking and branching is better preserved and has better thermostability. The reaction kinetics path of phenolic pyrolysis was reasonably summarized, revealing the generation mechanism of low-boiling molecules with less than 4 carbon atoms and large carbon clusters, which is in good agreement with the experimental results of activation energy and chemical bond energy. The reaction kinetics data obtained in this work provide a reliable basis for multi-scale reaction simulation.