Change of terminal type of alkylphenol formaldehyde resole by thermal treatment

Resole was thermally treated and was analyzed using atmospheric pressure chemical ionization–mass spectrometry (APCI–MS) to investigate the microstructural changes by heating. After thermal treatment, relative abundances of resoles having methylol (A) and hydrogen (H) terminals decreased whereas those of resoles having o-methylene quinone (Q) and aldehyde (K) terminals increased. Some resole species having AA- and HH-terminals were absolutely disappeared. Disappearance of H-terminal is due to reaction with A-terminal. Decrement or disappearance of A-terminal can be explained by conversion to Q- or K-terminal. Increase and new formation of K-terminal can be explained by conversion of A-terminal and dissociation of E-linkage.