Study On The Flame Retardant And Flame Retardant Stability Of PVC Coating For Architectural Membrane Material

Although PVC has a good flame retardant property, the flame retardant property of its products will drop significantly and then become combustible or flammable due to addition of plasticizers and other additives in the processing of applications. As it is used for a long time, the coating of PVC membrane material will inevitably suffer from external heat, light and then aging will occur. Some performances of the material may change including the combustion property. Therefore, it’s necessary to study the flame retardant and flame retardant stability of PVC coating for architectural membrane material.Based on a better overall performance of the material, a good fire-retardant formulation was obtained in this thesis by using flame-retardant plasticizer partly instead of conventional plasticizers and adding inorganic flame retardants. On this basis, the influence of thermal and light aging on the flame retardant stability of PVC coating material was studied by accelerated aging.First of all, flame-retardant plasticizer DPK was used to partly replace the conventional plasticizer. The results show that the DPK has a good flame retardant property in the condensed phase. Plasticized PVC by DPK and DINP, material has a good overall performance when the mass ratio is at10:50. On the basis of PVC plasticized by DPK and DINP,20parts inorganic compounded flame retardants Sb2O3/Al(OH)3were added. And then the material displays better performance when the mass ratio of Sb2O3and Al(OH)3is at1:2.Then PVC coating material was treated according to different thermal oxidation aging. The results show that the LOI value of the material first increases, then decreases and the trend is stable in the end after the treatment. Furthermore, with higher treating temperature, the LOI value of the material increases faster and stabilizes earlier. By EDS and the mass loss rate, it can be seen that in the primary of aging, plasticizers and other substances in the material decompose and volatilize, and later PVC degrades. After treatment the surface morphology of the material changes. The weight loss amount and loss rate of materials are less than those of untreated materials. The yellowness index of the material first increases and then stabilizes. With higher treatment temperature, it increases faster in the primary of aging, and stabilizes earlier during the aging. As aging time increases, the chemical composition on the surface of the material changes, and it affects the appearance and performance of the material.At last, PVC coating material was treated according to different light oxidation aging. It can be concluded that the LOI value of the material first decreases and then tends to be stable. What’s more, with stronger ultraviolet irradiation intensity, the LOI value of the material decreases faster and stabilizes earlier. On the analysis of EDS, it can be found that during the process of light oxidation aging, the material will draw off HC1continuously and the conjugated double bonds continues to be oxidated. When certain radiation is accumulated in the material, the aging tends to be stable. After the treatment the cracking phenomenon occurs on the material surface. The amount of weight loss is less than that of untreated materials and its weight loss rate is first slightly smaller and later a little larger than that of untreated materials. By the yellowness index and FTIR, it can be found that as the Ultraviolet irradiation intensity becomes greater, the rate of aging becomes faster and in the early aging time the material produces a certain amount of carbonyl that is broken later. As aging time increases, the chemical composition on the surface of the material changes, and it affects the appearance and performance of the material.