Sulfuric Acid → 4-Ethynylphenol

In 80 g of propylene glycol monomethyl ether was dissolved 88 g of p-t-butoxystyrene, and then, 2 g of azobisisobutyronitrile was added to the solution, after which they were subjected to polymerization for 10 hours under a nitrogen atmosphere while the reaction temperature was kept at 80° C. After the polymerization, an aqueous sulfuric acid solution was added to the reaction mixture and the resulting mixture was subjected to hydrolysis at 80° C. for 8 hours. Subsequently, ethyl acetate was added to the reaction mixture and the resulting mixture was washed with water, after which the solvent was replaced by acetone. The resulting resin solution was dropped into a large amount of water to coagulate a resin. The resin was recovered and dried in a vacuum drier kept at 50° C. overnight to obtain 48 g of a white fine powder of poly(p-hydroxystyrene).