Study on Hydrolytic Degradation of Polyester and Polyamide in Basic Solutions at High Temperatures

Plugging materials play a crucial role in oil production. Current development of temporary plugging agents still faces challenges such as insufficient sealing strength, poor temperature resistance, and complex manufacturing processes. To enable barrier materials for higher-temperature applications, we extensively studied the hydrolysis processes of aliphatic polyesters, polyamides, and thermosetting resins at different temperatures, analyzing the hydrolysis mechanisms of representative poly (butylene terephthalate) (PBT) and polyamide 6 (PA6). Inspired by the etching effect inspired by wood decay under humid environments, PBT was selected as the continuous phase to design and prepare a PBT/PA6 blend exhibiting physicochemical synergistic effects. The results indicate that PBT/PA6 blends exhibit significantly faster hydrolysis characteristics at 120 °C compared to pure thermoplastic polyesters. We found this to be the result of a synergistic effect where the terminal amine groups released during PA6 hydrolysis catalyze PBT hydrolysis, while the etching effect of the PBT continuous phase during hydrolysis accelerates PA6 hydrolysis. This study innovatively integrates physical-chemical synergistic effects, proposing a material design strategy that significantly enhances degradation rates.