Design and synthesis of a castor oil based plasticizer containing THEIC and diethyl phosphate groups for the preparation of flame-retardant PVC materials

Abstract

A fine chemical product based on a castor oil containing THEIC and diethyl phosphate groups (THEIC–MR-phosphate) was designed and synthesized, and it was used as a substitute flame retardant plasticizer to prepare PVC materials instead of the commercial plasticizer dioctyl phthalate (DOP). The performance of the PVC materials plasticized with THEIC–MR-phosphate was investigated with TGA, DSC, cone calorimeter analysis, and tensile tests. The results indicated that the addition of THEIC–MR-phosphate improved the flame retardant properties of the PVC materials. The time to ignition (TI) increased from 10 s to 25 s, the pHRR value decreased from 167.5 kW m⁻² to 52.1 kW m⁻², the av-HRR value decreased from 44.7 kW m⁻² to 21.1 kW m⁻², and the t-pHRR value increased from 45.0 s (D-1) to 73.0 s (N-3). These data indicated that the THEIC–MR-phosphate was effective in increasing the PVC material resistance to fire, and it not only decreased the HRR, but also delayed the fire process.