Studies On Flame Retardancy And Smoke Suppression Of PVC And ABS

With main concerns focused on the great smoke release amount of PVC and ABS, this paper aims at suppressing the smoke release of flame retarded PVC and ABS composites through preparing a new smoke suppressant and mixing it with other traditional suppressants on the base of implementing flame retardance. This paper includes four parts as follows:1. In an aqueous suspension of magnesium hydroxide, zinc aluminate was formed by the reaction between zinc sulfate and sodium aluminate and coated on the surface of magnesium hydroxide. The zinc aluminate coated magnesium(ZAMH), characterized by laser particle size analyzer, X-ray diffraction and powder's alkaline test, displayed approximate particle sizes and similar particle distribution in comparison with magnesium hydroxide. The total smoke rate of the flame retarded PVC with loading 10.6% ZAMH was10.36m2/m2, compared with loading 1.2% zinc aluminate and 10.6% magnesium hydroxide, reduced by 23.8% and 47.7% respectively; Smoke density rates also presented the decreasing consistency, zinc aluminate coated magnesium hydroxide 65, zinc aluminate 76 and magnesium hydroxide 90, respectively.2. On the base of the reduction of smoke release of ZAMH in flame retarded PVC, the combination of ZAMH and MoO3 could cut down the smoke density rates further. When mass ratio between MoO3 and ZAMH is 1:20 and the load is 11%, the smoke density rate of the flame retarded PVC dropped to 49, which reduced by 48.4%, 24.6% and 33.8% respectively, compared with blank one, 10.6% ZAMH and 0.6% MoO3.3. A synergistic flame retardant (MCA/MMT) was prepared through melamine cyanurate formation in an aqueous suspension of montmorillonite. Along with a nitrogen-phosphorus containing compound (PIPE) as the main flame retardant of ABS resin, the new complex displayed effective synergy in flame retardancy. When feeding 10% MCA/MMT and 15% PIPE to ABS resin, the resultant composite has a good tensile strength of 38.81MPa, impact strength of 9.05 kJ·m-2, vertical combustion FV-0, the burning time with flame 8s and the limited oxygen index 29.5%. Based on the formulation, loading 1% mica and 1.5% zinc borate could further improve flame retardancy of the generated composites by increasing the limited oxygen index to 30.4% and 31%, and decreasing the burning time with flame to 6s and 4s respectively.4. The effect of smoke suppressant compounds composed with melamine octamolybdate (MOM) and zinc aluminate(ZA) was studied in flame retarded ABS which feeded 10% MCA/MMT and 15% PIPE through smoke density chamber, cone calorimeter and thermogravimetric analysis (TGA). It was found that when the moss radio of MOM and ZA is 1:3, the smoke suppressant compound can improve char formation and lead to a better effect of smoke suppression. Adding 3.8% of this compound to flame retarded ABS could lead to a smoke density rate of 47 and a total smoke rate of 22.03m2/m2, reduced by 46% and 48.5% respectively, compared with the case of no suppressant.