An efficient Urea-formaldehyde resin degradation method by hydrogen peroxide and malic acid: At three-mole ratios

•Malic acid/H2O2 (HPMA) method efficiently degrades cured UF resins.•Process includes acidic hydrolysis & H2O2 oxidation.•High molar ratio UF resins exhibit greater degradation resilience.•FTIR, XRD, NMR confirm structural changes during degradation. Urea-formaldehyde (UF) resin has a high annual output, but the used and waste UF resin poses a challenge for recycling due to the difficulty in effectively decomposition them. In this study, A novel one-step degradation method was proposed, i.e., using eco-friendly malic acid and hydrogen peroxide to degrade cured UF resin residues using carboxylic acid through the hydrothermal oxidation method (HPMA), which was proved to have high cured UF resin degradation efficiency. This method will offer a new path for effectively recycling the UF resin out of service.