Abstract: The thermal decomposition behavior and composition of gas phase products of phenolic resin quartz fibers during thermal decomposition at a heating rate of 20 ℃/min and 20 ℃/ms to a certain temperature were investigated by thermogravimetric analysis-mass spectrometry (TG-MS) and pyrolysis-gas chromatography-mass spectrometry (Py-GCMS). The results show that the thermal decomposition process of phenolic resin impregnated quartz fiber composites is consistent with that of phenolic resin, and can be divided into three stages: dehydration and gas loss stage at 20~400 ℃; The main stage of pyrolysis is from 400 ℃ to 800 ℃, and the main gaseous products are water, methane, carbon dioxide, benzene, phenol, and derivatives of benzene and phenol; When the temperature exceeds 800 ℃, the pyrolysis has basically completed. The main thermal decomposition products and relative content of phenolic resin impregnated quartz fiber composites at 600, 800, and 1 000 ℃ are basically the same as those of phenolic resin; This indicates that the pyrolysis of phenolic resin impregnated quartz fiber composites is mainly due to the pyrolysis of phenolic resin, and quartz fibers do not participate in the pyrolysis reaction.

Key words: ablative material, phenolic resin impregnated quartz fiber, thermal decomposition, thermogravimetric analysis-mass spectrometry, pyrolysis-gas chromatography-mass spectrometry