Synthesis and application of phosphaphenanthrene groups-containing soybean-oil-based plasticizer

A novel flame retardant plasticizer phosphaphenanthrene groups-containing soybean oil polyol ester (PSOPE) was synthesized via the alcoholysis, epoxidation, ring opening and esteriflcation from soybean oil. Its chemical structure was characterized with Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (H-1 NMR) and phosphorus nuclear magnetic resonance (P-31 NMR). Flame retardant poly (vinyl chloride) (PVC) blends plasticized different content of PSOPE were prepared. The thermal stability, flame retardant performance, mechanical property and migration stability of PVC blends was investigated. The results showed that limiting oxygen index (LOI) value of flame retardant PVC blends reached 36.2%. The thermal degradation of PSOPE could promote the formation of char residue which could further improve the thermal stability and flame retardant performance of PVC blends dramatically. Cone calorimeter tests showed that theses char residue plays the role of smoke-suppressant during the combustion of PVC blends. The smoke-suppressant effect caused the lags of smoke production rate peak and decrement of the total smoke production. When PVC blends plasticized with only PSOPE, the tensile strength and elongation at break of PVC blends reached 22.84 MPa and 278.39%, respectively. The high migration resistance of PSOPE could keep property of PVC products long-term stabilization. All of the efficient effect on PVC blends proved that PSOPE could be used as a flame retardant plasticizer. (C) 2015 Elsevier B.V. All rights reserved.