Preparation and properties of multicomponent halogen-free flame retardant natural rubber based on phosphoxanthrene derivatives

Abstract

The flame retardant natural rubber （NR） vulcanizates were prepared by adding phosphoxanthrene/triazine bibase synergic flame retardant（TGD）, dimethyl methyl phosphonate （DMMP）, expandable graphite （EG） and aluminum hydroxide （ATH） to NR. The effects of TGD/DMMP/EG/ATH compound flame retardants on the flame retardancy, thermal stability and physical and mechanical pro-perties of NR vulcanizate were investigated. The results showed that TGD/DMMP/EG/ATH compound flame retardant could effectively improve the flame retardancy and thermal stability of NR vulcanizates, and reduce the heat release rate during combustion. When the amount of TGD/DMMP/EG/ATH compound flame retardant was 60 phr （mass）, the limiting oxygen index of NR vulcanizates could reach 28.4%, the mass fraction of carbon residue could reach 25.61%, the heat release rate and total heat release amount of NR vulcanizates could be reduced by 95% and 21%. TGD/DMMP/EG/ATH compound flame retardant had little effect on the physical and mechanical properties of NR vulcanizates.

Keywords

• natural rubber
• phosphozapine/triazine diphenyl synergistic flame retardant
• compound flame retardant
• flame retardant performance
• thermal stability
• physical and mechanical property