Study On Flame Retardant And Smoke Suppression Characteristics Of Flame Retardant Microcapsule Silicone Foam

Silicone foam material(SiF)combines silicone rubber materials with non-toxic,environmentally friendly,heat-resistant and foam insulation,sound absorption and high impact resistance.Because the nature is combustible,and the foam material increases its specific surface area,the combustion space increases.Therefore,its popularization and application in some fields are limited.Therefore,reducing the combustibility of silica foam materials is of great significance to popularize its application.Using phenyltrimethoxysilane,N-(beta-aminoethyl)-gamma-aminopropyl methyl dimethoxysilane and hexamethyldisiloxane as raw materials,using ammonium polyphosphate(APP)and aluminum hypophosphite(AHP)as core materials,MAPP and MAHP were prepared.The coating reliability of microcapsule flame retardant was characterized by FTIR,SEM and TG.Then ATH and ZB were selected to blend with MAPP and MAHP to obtain MAPP-ATH/SiF,MAHP-ZB/SiF and MAPP-ATHAMAHP-ZB/SiF.The flame retardancy and mechanical properties of the materials were analyzed by oxygen index(LOI),vertical combustion(UL-94)and rubber tensile testing machine.The fire hazard and thermal stability of flame retardant silicone foam were characterized by thermogravimetric analysis and cone calorimeter.It mainly includes the following contents:The vibration peaks of the groups represented by the wall materials appeared in the FTIR spectra.Combined with SEM,many fine particles on the surface of the core materials and the residual amount of the microencapsulated flame retardant increased,indicating that the flame retardant was coated.In MAHP-ATHISiF and MAHP-ZB/SiF,the oxygen index(LOI)and mechanical properties were improved,and the vertical combustion reached UL-94V-0.When MAPP-2wt%ATH,the LOI value was 30.6%,and when MAHP-1.5wt%ZB,the LOI value was 30.7%.The peak heat release rate(PHRR),effective combustion heat(EHC)and total heat release(THR)smoking rate(SPR)of the samples decreased compared with the original.The fire risk of MAHP-ZB sample is less than that of MAPP-ATH.In MAHP-ZB/MAHP-ZB/SiF,when the content ratio of MAPP-ATH to MAHP-ZB was 1:2,the LOI value was 31.9%,the ignition time was delayed to 145 s,and the PHRR and THR values were 56.84 kW/m2 and 20.11 MJ/m2,respectively,with the best thermal stability.The carbon layer is relatively dense and compact,and has obvious stratification characteristics from the side.