Diego Penzo, Bruno Godinho, Gabriele Rossignolo, Michele Modesti, Artur Ferreira, Alessandra Lorenzetti, Ana Barros‐Timmons, Nuno Gama
Abstract This study focuses on the sustainability of plastics reporting the recycling of polyamide (PA) using a dicarboxylic acid through an acidolysis process. PA 6 was depolymerized with adipic acid and the influence of reaction conditions on the characteristics of the recycled products (RPs) was evaluated. Harsher conditions (higher temperature and time) increased the depolymerization yield and temperature was statistically identified as a significant factor affecting the process. In addition, linear regression was used to obtain coefficients that describe the effect of the reaction conditions on the properties of the RP. The RPs were subsequently used to partially replace up to 30% of 6‐aminohexanoic acid in the synthesis of new PA 6. Phase separation was observed when the RP was incorporated into PA 6, affecting the properties of the resulting materials, but only at higher substitution levels. However, no significant differences were detected in chemical or crystalline structure. Overall, this work demonstrates the potential of dicarboxylic‐acid‐based PA depolymerization as a strategy to improve plastic sustainability. © 2026 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.