Synthesis, characterization, and performance evaluation of a high-efficiency fully biobased biodegradable plasticizer

Developing bio-based plasticizers not only aids in the reduction of fossil fuel consumption but also presents a lower risk to human health. In this study, a fully biodegradable plasticizer—levulinate malate ethanol lactates (LMEL) was successfully synthesized from L-lactic acid, DL-malic acid, levulinic acid, and ethanol, and was compared with commercially plasticizers (acetyl tributyl citrate (ATBC), dioctyl phthalate (DOP) and di-2-ethylhexyl terephthalate (DOTP)). 40 phr LMEL plasticized polyvinyl chloride (PVC) (40LMEL) yielded a remarkable elongation at break of 526.9%, compared with the pure PVC resin (4.5%), thereby significantly enhancing the flexibility of PVC. Moreover, the optical transparency of 40LMEL samples was found to be equivalent to PVC plasticized with three commercial plasticizers. Most importantly, compared with three commercial plasticizers, 40LMEL exhibited superior resistance to migration and volatility, with mass losses of 1.055% in H₂O, 13.601% in n-hexane, 14.636% in ethanol, and 1.496% in activated carbon, respectively. Soil degradation experiments have demonstrated that LMEL can be broken down by microorganisms in the soil into nontoxic aliphatic compounds (e.g., 4-oxo-pentanoic acid, and 4,5,7-trihydroxy 2-octenoic acid, et al.). Collectively, LMEL exhibited better overall performance than three commercial plasticizers. This work provides new options for the design of efficient fully bio-based plasticizers.