Internally plasticized PVC by four different green plasticizer compounds

In this work, the phthalate-free internally plasticized polyvinyl chloride (PVC) materials were developed by covalent attachment of tributyl citrate (TBC), propargyl ether tributyl citrate (PrTBC), oleic acid, and poly(dimethylsiloxane) diglycidyl ether terminated (PDMS, Mn similar or equal to 800) to the PVC matrix. The obtained modified PVC (M-PVC) materials through different synthesis routes abbreviated with PVC-TBC1, PVC-TBC2, PVC-Oleic, and PVC-PDMS, respectively. The M-PVCs were characterized by FT-IR, H-1 NMR, GPC, TGA, DSC, tensile and migration stability tests. The TGA thermograms indicate the M-PVC materials, especially PVC-PDMS and PVC-Oleic, have higher thermal stability than PVC. The internally plasticized PVCs show the lower Tg compared to PVC. The Tg of the neat PVC is 84 degrees C, meanwhile, the Tg of the PVC-PDMS, PVC-TBC1, PVC-Oleic, and PVC-TBC2 were decreased to 62.6, 53.0, 42.8, and 41.0 degrees C, respectively. By substitution of chlorine atom with plasticizers, tensile strength decreased from 41.35 MPa down to 25.01 MPa and the elongation at break increased from 40.80% up to 90.27%. Besides, no migration was observed for these M-PVCs in petroleum ether, 30% (w/v) acetic acid, 10% (v/v) ethanol, and distilled water. Hence, the results showed that plasticization of the PVC was successfully performed by these covalent plasticization without any migration. These strategies are expected to be scalable, and provide a viable alternative to the use of phthalates, thus decrease the human health threat and environmental risks.