Synthesis of 2‐Methyl‐1,3‐Propanediol Modified Azelaic Acid‐Octanediol Copolyester Plasticizers and Their Plasticizing Effect on Polyvinyl Chloride

ABSTRACT Currently, mainstream phthalate plasticizers pose serious threats to the environment and human health. As an eco‐friendly and harmless alternative, polyester plasticizers have garnered widespread attention. However, their complex preparation process and low plasticizing efficiency have limited their practical application. In this study, a series of copolyester plasticizers (POMAZ), synthesized from azelaic acid, octanediol, and various contents of 2‐methyl‐1,3‐propanediol (MPO), were prepared via direct esterification. The preparation process is controllable, and the number‐average molecular weight of POMAZ ranges from 1000 to 4000, with a thermal degradation temperature above 270°C, demonstrating excellent thermal stability. PVC samples plasticized with POMAZ showed a decrease in glass transition temperature to −30°C and increased hydrophilicity with higher MPO content. Measurements of the tensile elongation at break of plasticized PVC verified the outstanding plasticizing performance of the POMAZ series. Specifically, POMAZ‐45/PVC exhibited an elongation at break of up to 975.3%, with a plasticizing efficiency reaching 273.2%.