Mechanism of Hydrolysis of Nylon 66 with Nylon Hydrolase Enzyme

Nylons (polyamides), widely used in industrial and textile applications, face significant challenges in recycling. The difficulties arise from high melting points, and the presence of additives that complicate processing and makes the process of recycling energy intense. As an alternative to current methods of recycling like mechanical or chemical recycling, enzymatic hydrolysis could provide a selective and energy-efficient route with a lower cost to deconstruct nylons. However, the challenge associated with nylon deconstruction using enzymatic hydrolysis is the low yield of enzymatic hydrolysis. This necessitate a closer look into the mechanism of enzymatic hydrolysis. In the present study, we investigate the influence of molecular weight on the enzymatic hydrolysis of nylon. To address this, we synthesized Nylon 66 and characterized materials using tools such as differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS), and Brunauer-Emmett-Teller (BET) analysis. Enzyme nylon hydrolase (NylC) was used for deconstructing the Nylon 66, and the products were analyzed using mass spectrometry (MS) and gel permeation chromatography-size exclusion chromatography (GPC-SEC). The correlation between the enzymatic reaction products and the properties of as-synthesized nylons was revealed.