Effect of quantitative characteristic structure of resole phenolic prepolymer resin on thermal stability, pyrolysis behaviors, and ablation properties

Abstract

The chemical structure of resole phenolic prepolymer resin is difficult to be accurately described because it is a mixture composed of different polymerization degree structures. Limited by the knowledge of prepolymer resin structure, the cross-linking degree (CLD) of cured resin and the effects of structure on the ablation properties remain unclear. The objective of this work is to understand the relationship between prepolymer resin structure, CLD of cured resin, and performance. The quantitative characteristic structure of resole prepolymer and CLD of curing resin was proposed in this work based on the full understanding of the chemical structure. A fast and accurate identification method was provided for the quality conformity identification of mass production of resole prepolymer phenolic resin. A novel CLD characterization method for high cross-linking resole phenolic resin was proposed. The results showed that the ablation properties of resole phenolic resin are optimum when formaldehyde/phenol value of prepolymer is in the range of 1.20–1.46. This study may provide meaningful information to the understanding of the ablation mechanism of resole phenolic resin, which is a benefit for developing novel anti-ablation resin.