Decomposition of Prepolymers and Molding Materials of Phenol Resin in Subcritical and Supercritical Water under an Ar Atmosphere

Seven prepolymers of phenol resin were decomposed into their monomers such as phenol, cresols, and p-isopropylphenol by reactions at 523−703 K under an Ar atmosphere in subcritical and supercritical water. The total yield of identified products depended on the kind of prepolymers, and the maximum yield reached 78% in the reaction at 703 K for 0.5 h. The decomposition reactions were accelerated by the addition of Na2CO3, and the yields of identified monomers reached more than 90%. Two kinds of molding materials of phenol resin whose content of phenol resin was less than 50% were also decomposed mainly into phenol and cresols by the reaction in supercritical water.