Efficient depolymerization and chemical conversion of polyamide 66 to 1,6-hexanediol

Polyamide 66 was efficiently depolymerized and chemically converted by treatment with supercritical MeOH in the presence of glycolic acid. The dicarboxylic acid unit of the polymer was selectively converted to dimethyl adipate, while the diamine unit of the polymer was converted to 1,6-hexane diol via a tetramethyldiamine intermediate. The reaction in the absence of glycolic acid was sluggish, and the yields of the diester and the diol were poor. Thus, glycolic acid efficiently catalyzed the reaction to produce 1,6-hexanediol in high yield.