PAPP-g-VTES阻燃改性EVA防水板性能研究OA

This study aims to develop halogen-free flame-retardant waterproofing sheets with both excellent flame retardancy and good mechanical properties,thereby addressing safety risks caused by the flammability of tunnel waterproofing sheets and preventing tunnel seepage and leakage.Ethylene-vinyl acetate copolymer modified polyethylene(EVA/PE)was used as the matrix,and vinyltriethoxysilane(VTES)graft-modified piperazine pyrophosphate(PAPP)was employed as the flame retardant(PAPP-g-VTES);flame-retardant waterproofing sheets were prepared by melt blending.The effects of PAPP-g-VTES content on flame-retardant properties(limiting oxygen index(LOI),UL-94 vertical burning rating,cone calorimetry results(THR/TSR),and single burning item classification)and mechanical properties(tensile strength,elongation at break,and tear strength)of the composites were systematically investigated.The results showed that,as the PAPP-g-VTES content increased,the flame-retardant performance of the composites improved significantly,whereas their mechanical properties decreased to some extent.When the PAPP-g-VTES content was 25 wt％,the composite exhibited the best overall performance,with the LOI reaching 29.5％,representing a 55.3％increase compared with the unmodified composite.The UL-94 test achieved a V-0 rating.The total heat release(THR)and total smoke release(TSR)decreased by 24.3％and 65.2％,respectively,compared with the unmodified composite.The single burning performance grade reached B1.Meanwhile,the composite still maintained good mechanical properties,with a tensile strength of 17.5 MPa,an elongation at break of 654％,and a tear strength of 92 kN/m.This study provides an important reference for the development of high-performance flame-retardant waterproofing materials.