Research On Design,Preparation And Application Of Flame Retardant System Of Cyclophosphazene

Rigid polyurethane foam(RPUF)is one of the most versatile engineering materials and has a wide range of applications in production and life.Epoxy resin(EP)is one of the most representative thermosetting polymers.Because of its excellent performance,it is widely used in aerospace,adhesives and other fields.However,both are flammable,which will greatly limit the application of materials,so it is very necessary to antiflame rigid polyurethane foam and epoxy resin.In this project,a reactive core-shell structure flame retardant EG@PZS with expandable graphite(EP)coated with cyclophosphazene derivative was prepared by in-situ polymerization and applied to rigid polyurethane foam and epoxy resin.While being halogen-free,environmentally friendly and flameretardant,it also reduces the impact on the mechanical properties of the matrix materials.The main research results are as follows:1.By optimization,a suitable expandable graphite dispersant and solvent were obtained,and the amount of dispersant was established,and a stable expandable graphite suspension was obtained.Cyclophosphazene and bisphenol S was polymerized in situ on the surface of expandable graphite under the action of acid binding agent to obtain a reactive core-shell structure flame retardant EG@PZS.2.RPUF was prepared through one-step all-water foaming by myself.The reactive flame retardant EG@PZS was applied to it,and the LOI of the modified RPUF was 25.5%,reaching UL-94 V-1 rating.TGA showed that the modified RPUF had better thermal stability.The compressive strength of modified RPUF by EG@PZS is significantly higher than that of EG/RPUF.3.The reactive flame retardant EG@PZS was applied to EP.The flame retardancy and thermal stability of the modified epoxy resin were studied,and the influence of EG@PZS on the impact strength of EP was explored.The results showed that the LOI of 14%EG@PZS/EP reached 27.4%,and UL-94 reached V-0 rating;TGA test showed that the modified EP had excellent thermal stability.Additionally,the impact strength of modified epoxy resin was further improved,indicating that EG@PZS had the effect of toughening EP.