Synthesis and evaluation of oleic acid-derived hyperbranched polyester as an efficient plasticizer for PVC

In response to the health and environmental concerns associated with the plasticizer dioctyl phthalate (DOP), this research explores the utilization of methyl oleate (MO) derived from plant oil, 1,2,4-Benzeneticarboxylic anhydride (TMA) and isobutyric anhydride (IA) as a precursor for synthesizing a hyperbranched polyester named IA-MO-TMA. This polyester serves as an alternative plasticizer for Polyvinyl chloride (PVC). The chemical structure of IA-MO-TMA was thoroughly characterized using Fourier Transform Infrared Spectrometer (FTIR) and nuclear magnetic resonance hydrogen spectra, and its molecular weight was assessed. The PVC film, plasticized with IA-MO-TMA, underwent comprehensive testing using techniques such as differential scanning calorimetry, scanning electron microscopy, and thermogravimetric analysis. Notably, the glass transition temperature ( T g ) of the plasticized PVC film exhibited a significant reduction from 75°C to −6.7°C. The plasticized film demonstrated an elongation at break of 318.1%, a tensile strength of 19.2 MPa, and a plasticizing efficiency of 109.9%. Moreover, the use of IA-MO-TMA as a plasticizer increased the initial decomposition temperature of PVC film from 235.6 to 264.1°C. Additionally, the extraction rate of IA-MO-TMA in petroleum ether was found to be 35.6% lower than that of DOP.