Abstract:

Biobased plasticizers mixtures have potential use as nontoxic and sustainable plasticizers and as replacements for commonly used phthalate plasticizers. In this work, Epoxidized sunflower oil (ESO) and epoxidized sunflower oil methyl ester (ESOME) were prepared respectively by epoxidation of sunflower oil (SO) and transesterification reactions of epoxidized sunflower oil (ESO) and used as secondary biobased plasticizers with acetyl tributyl citrate (ATBC) as primary biobased plasticizers . Samples prepared by different combinations of ESO, ESOME and ATBC were mixed with poly (vinyl chloride) (PVC) using two roll mill at 160C during 10 minutes. Samples prepared were characterized by discoloration sheets, thermogravimetric analysis (TGA), dynamic mechanic thermal analysis (DMTA) and mechanical properties. The changes in discoloration degrees for the PVC films were minimal in the films plasticized with system contain ESO or ESOME, when Epoxy groups of ESO and ESOME react with HCl evolved by dehydrochlorination of PVC. The TGA results obtained in this study show that the PVC mixed with ATBC alone begins to lose its weight at a lower temperature than those formulations mixed with ESO or with ESOME. Hence, ESO and ESOME could improve the thermal stability of PVC blends with ATBC. All samples exhibited a single transition temperature (Tα). This temperature is an important parameter to evaluate the plasticizing effects of substances system added to PVC. The elongation at break increases in the case of ATBC with ESO or ESOME. Evidence is presented which shows that the combination of ESO, ESOME and ATBC performs a dual role of stabilizing and plasticising PVC.