Study on the microstructure evolution of phenol-formaldehyde resin modified by ceramic additive

Abstract

Boron carbide (B₄C) was selected as the additive for the modification of a phenol-formaldehyde (PF) resin, and the micro-structural evolution of the modified resin at high temperature was investigated. Results showed that the distribution of B4C particles became uniform at elevated temperatures. The primary oxidation of B₄C started to occur at 450vH, and lots of B₂O₃ was formed above 650vH. By the modification reactions of B₄C, the volatiles including CO was converted into amorphous carbon and remained in the resin matrix, which was responsible for maintaining the stability of the resin at high temperatures.