Synthesis of a novel polysiloxane containing phosphorus, and boron and its effect on flame retardancy, mechanical, and thermal properties of epoxy resin

Abstract

In this paper, a novel polysiloxane containing phosphorus and boron (PSPB) has been successfully synthesized. The chemical structure of PSPB was characterized by means of FT‐IR, XRD, and NMR. The resulted PSPB was used as flame retardant and incorporated into the epoxy (EP) resin to prepare PSPB/EP composites. The effect of PSPB content on the mechanical properties, thermal stability and flame retardancy of composites was studied by impact and bending test, TGA, DMA, and limiting oxygen index (LOI) test. The results revealed that the incorporation of PSPB increased the mechanical properties and thermal stability of composites. The glass transition temperature (Tg) of the composites was decreased with the increasing of PSPB content. The morphology of the fracture surface of PSPB/EP composites was studied by SEM, indicating that the PSPB had good compatibility with epoxy resin. Moreover, the LOI results indicated that the incorporation of PSPB could significantly enhance the flame retardancy of composites. The LOI value of PSPB/EP composites with 20 wt% PSPB was about 28.4%, whereas the neat epoxy resin had a LOI of 20.8%. POLYM. COMPOS., 39:807–814, 2018. © 2016 Society of Plastics Engineers