Study On The Flame Retardant And Smoke Suppression Effect Of CoS Coated Particles On PVC Materials

Soft PVC is widely used from all walks of life and industrial because of its electrical insulation, ageing resistance and lower price, a large amount of plasticizer are added in the production of PVC leading to limit oxygen index decrease significantly and release a large number of poisonous and harmful gases.Therefore to seek a kind of flame retardant, high efficiency, low toxicity, low smoke pollution-free flame retardants is particularly important.In this paper, I prepare four particles of ZHS coated MH, M-HOS, ATH, CC at the same addition level,8.2%. on the basis of predecessors’ research, the prepared ZHS coated fillers were characterized by XRD and TEM.Fire retardant properties, including LOI, UL 94 V, CONE, TGA have been measured and compared for unfilled and filled polyvinyl-chloride (PVC) based cable formulations, containing various amounts of uncoated and ZHS-coated MH, M-HOS, ATH, CC fillers. The conclusions are as follows:(1)ZHS which is coated on the surface of inorganic particles, does not change the particle structure, they are formed relatively complete core-shell structure which is inorganic particles as nuclear and ZHS as shell(2) Flame retardant effect of PVC which is mixed with ZHS coated particles is significantly higher than that of PVC is mixed with ZHS and inorganic particles mechanical blending.In the four flame retardant materials, hydroxy stannate zinc coated aluminum hydroxide particles on the mechanical properties of PVC matrix damage is smaller.(3)Flame retardant smoke suppression effect of PVC which is mixed with ZHS coated MH is significantly higher than that of PVC which is mixed with ZHS and MH mechanical blending under the condition of the same thermal radiation.Cone calorimeter test results show that the ZHS coated M-HOS has ideal smoke suppression effect, but the inhibitory effect of harmful gases (CO) to release the effect is not obvious, and hydroxy stannate zinc coated aluminum hydroxide as a flame retardant smoke suppression agents can better inhibit the release of the CO, the peak release rate minimum and peak width is also the most narrow.When the PVC is burning to the time of 60 s,180 s and 300 s, the average heat release rate is the lowest. The PVC which is mixed with ZHS coated ATH can effectively reduce the release of the heat and harmful gas that will reduce the fire risk.