Study On The Synergistic Flame Retardant Epoxy Composite With MOFs@ Short Carbon Fiber And APP

In this paper,,three kinds of MOFs/carbon fiber composite systems were designed and prepared based on the characteristics of metal organic framework materials(MOFs)and chopped carbon fibers(SCFs),and they were compounded with ammonium polyphosphate(APP)and added in epoxy resin(EP)to improve its flame retardancy.The mechanical properties,thermomechanical properties,thermal stability,flame retardancy,smoke suppression properties and corresponding mechanisms of EP composites were discussed.ZIF-8@SCFs was prepared by grafting the zeolite-like imidazole framework(ZIF-8)onto the surface of SCFs.ZIF-8@SCFs was added into EP matrix with APP to prepare ZIF-8@SCFs/APP/EP composite materials.The mechanical properties,thermomechanical properties,thermal stability,flame retardancy and smoke suppression properties of the prepared composite materials were investigated.The experimental results showed that adding ZIF-8@SCFs can improve the dispersion of APP in the matrix,the mechanical and thermomechanical properties of the prepared composite materials.When the content of ZIF-8@SCFs was 1 wt%(the content of APP was 4 wt%),the tensile strength and bending strength of the composite material were increased to 58.0 MPa and 91.5 MPa,respectively.The storage modulus G’(40 ℃)and T_gof the composite material were increased to 1560 MPa and 142 ℃.Moreover,the limiting oxygen index(LOI)of the composite material reached 28.1%and UL-94 test of the composite material reached the V-1 level.(Fe)MIL-101@SCFs was synthesized by loading the iron-based Levasir frame material((Fe)MIL-101)onto the surface of SCFs with the solvothermal method.(Fe)MIL-101@SCFs/APP/EP composite materials were prepared with EP,APP and(Fe)MIL-101@SCFs.The results showed that the addition of(Fe)MIL-101@SCFs could improve mechanical properties and flame retardancy of the prepared composite materials.When the content of(Fe)MIL-101@SCFs was 1 wt%(the content of APP was 4 wt%),the tensile strength,flexural strength,G’(40 ℃)and T_g of the composite material were increased to 53.1 MPa,116.5 MPa,1814 MPa and 152 o C,respectively.Besides,the LOI of the composite material reached 27.6%.UL-94test of the composite material reached the V-1 level.CoZn-ZIF@SCFs was prepared by grafting a bimetallic zeolite-like imidazole framework(CoZn-ZIF).EP,APP and CoZn-ZIF@SCFs were mixed to prepare the flame retardant composite material(CoZn-ZIF@SCFs/APP/EP).The results showed that CoZn-ZIF@SCFs/APP had a synergistic flame-retardant effect,which can also be used as a compatibilizer to improve the mechanical and thermomechanical properties of materials.When the content of CoZn-ZIF@SCFs was 1 wt%(the content of APP was 4 wt%),the tensile strength and the bending strength of the composite material were increased to 51.48 MPa and 117.2 MPa,respectively.G’(40 ℃)and Tg of the composite material were increased to 1962 MPa and 154℃,respectively.The LOI value of the composite material reached 28.9%and V-0 rating in UL-94 was attained.At the same time,the total smoke emission(TSP)was dropped to 41.7 m~2.