In Silico Screening of Green Plasticizers for Poly(vinyl chloride)

Phthalate derivative plasticizers used in poly(vinyl chloride) (PVC) processing have been a subject of concern because of their possible toxicity. Hence, there is a growing interest toward new, nontoxic, "green" plasticizers. In this work, the performances of biobased plasticizers including esters of succinic, levulinic, oleic, and adipic acids were compared in reference to the conventional plasticizer bis(2-ethylhexyl) phthalate (aka dioctyl phthalate or DOP). For this purpose, molecular dynamics (MD) simulations were used to determine polymer/plasticizer interactions and to predict thermomechanical properties of polymer mixtures. The variation of glass temperatures (T-g) of the systems was investigated, and the stabilities of the polymer/plasticizer mixtures were compared through the Flory-Huggins solubility parameter. The mechanical properties were investigated through nonequilibrium MD simulations. Young's modulus and yield strength values were predicted through stress-strain curves. The results suggest that succinic acid derivatives have the potential to replace phthalate derivatives due to their good solubility in PVC and their effectiveness in reducing the T-g.