Effect of hydrolysis stabilizers on anti-aging performance of PET under pressure cooker test

Polyethylene terephthalate (PET) is extensively utilized in various industries due to its good properties. However, as a kind of polyester, PET is apt to hydrolysis when exposed to moisture and heat, which severely affects its performance and service life. Hence, the incorporation of hydrolysis stabilizers is a common mitigation method. In this work, the PET specimens modified by two types of hydrolysis stabilizers were subjected to the pressure cooker test to evaluate the improvement effect, and the resultant changes in appearance, mechanical properties, and thermal characteristics were studied. Additionally, the crystallinity and infrared peaks were detected to assess the effectiveness of the hydrolysis stabilizers and to reveal the aging mechanisms of PET. The results indicated that PET underwent three distinct aging processes during the pressure cooker test, including crystallization, water plasticization and hydrolysis, and the inhibitory effect of the hydrolysis stabilizers mainly reflected in the crystallization and hydrolysis processes while the effectiveness depended on their types and concentrations.