Flame retardant properties and thermal degradation kinetics of modified montmorillonite/zinc borate/silicone rubber foam composite
In order to improve the flame retardant performance of silicone rubber foam,organically mod-ified montmorillonite and zinc borate were added as flame retardants to silicone rubber foam,and organ-ically modified montmorillonite/zinc borate/silicone rubber foam composites were prepared by room temperature vulcanization method,and the flame retardant properties of SRF composites were studied by limiting oxygen index,horizontal-vertical combustion test and smoke density test.The thermal stabil-ity and pyrolysis gas composition of the composites were studied by thermogravimetry-infrared analysis,and the thermodynamic analysis of thermal degradation of composites was carried out by non-isothermal method.The results show that the LOI of the composites reaches a maximum of 29.5%when 2wt%OMMT and 1wt%ZB are added,which is 11.3%higher than that of pure SRF.The maximum smoke density and smoke density grade are reduced by 32.9%and 34.1%respectively compared with pure SRF,which delays the thermal decomposition process of SRF composites and increass the amount of carbon residue.The activation energy of 2wt%OMMT/1 wt%ZB/SRF composites is significantly im-proved in the later stage of pyrolysis,indicating that the combination of OMMT and ZB can effectively improve the flame retardant and smoke suppression properties of SRF composites,and the flame retard-ant effect is mainly reflected in the later stage of pyrolysis.