Development of biocompatible azelaic acid-based copolyester plasticizers for PVC applications

In this study, the copolyester plasticizers PHNAZ, synthesized from azelaic acid and hexanediol and modified by neopentyl glycol (NPG), was prepared via direct esterification. A series of characterization tests revealed that the number-average molecular weight of the PHNAZ copolyester plasticizers was less than 2000 with a dispersion coefficient of less than 2, demonstrating excellent thermal stability below 250 °C. PVC samples plasticized with PHNAZ showed thermal degradation temperatures above 250 °C, reduced glass transition temperatures to −33 °C, and significantly improved hydrophilicity. Notably, the water contact angle of PHNAZ-50/PVC was smallest, averaging 53.956°. The highlight of the study is the cytotoxicity testing of the prepared PHNAZ copolyester plasticizer at concentrations of 1 μg/mL, 10 μg/mL, and 50 μg/mL, where the average cell survival rate exceeded 100 %, indicating excellent biocompatibility. Additionally, PHNAZ displayed outstanding plasticizing effects, particularly PHNAZ-20/PVC, which achieved an elongation at break of 913.6 % and a plasticizing efficiency of 260.0 %. These results suggest that PHNAZ not only excels in chemical and thermal properties but also exhibits good biocompatibility and high plasticizing capability, indicating broad application prospects.