Surface Modification And Flame Retardant Applications Research Of Antimony Trioxide

Most polymeric materials are inflammable; they will generate massive smoke and harmful gas in the combustion process, which severely threaten human life and health. Therefore, it is significant that fire-retardant treatment be used in polymeric materials.Antimony trioxide is a highly efficient flame retardant, used independently or cooperated with other synergistic flame retardant. Recently antimony trioxide is widely used in textiles, paper, plastics and other fire-retardant treatment. Because of its poor dispersion, surface modification will be done prior to its fire-retardant applications in this experiment.(1) Surface modification of antimony trioxideSurface modifying of Sb2O3by stearic acid in single factor testing, the modification conditions were obtained as following:Modification temperature85℃, modification time45min,3%dosage of stearic acid, the activation index of modification Sb2O3can reach40.2%. Though there was no changing of the structure of Sb2O3, the surface of Sb2O3generated a chemical reaction showed by FTIR. After surface modification, Sb2O3was well-distributed observed through SEM.(2) Application of modified antimony trioxide in Flexible PVCThe flame retardant treatment experiment was made, which was adding the modification Sb2O3in flexible PVC. The experimental result was that the modified antimony trioxide has few effects on the mechanical properties on the composite system, and the oxygen index test showed that surface modification does not affect its flame resistance. While added3phr modified trioxide in experiment, the composite system had a good mechanical properties and the oxygen index could reach to31.3. In this condition, the flame resistance of the composite is good and the cost is lower.(3) Preparation process of PVC/Salix psammophila powder wood-plastic composite materialThe best preparation process of PVC/Salix powder composite material would be confirmed in order to study on the flame resistance of modified Sb2O3which was added in the composite material. The following optimum technological parameter were confirmed by range analysis used in the study:15min pressing time,6:4wood and PVC ratio,10min mixing time, and coupling mass amount is3%of the flour mass.(4) Application of modified antimony trioxide in PVC/Salix powder composite materialShowed from experiment, no matter modified or not, antimony trioxide has influences on the mechanical properties of wood-plastic composites. However the modified antimony trioxide in the composite system has better dispersion and less influence on physical and mechanical properties of the composites. Surface modification does not affect the flame retardant of antimony trioxide. From the form of the combustion product, we observed that the carbon residue layer is thick which can effectively curb the spreading of fire. FTIR showed the principle of antimony trioxide flame retardant, which antimony trioxide react with HC1released by PVC pyrolysis, form a protective layer and diluting the oxygen. Contact angle test showed that the retardant PVC/Salix powder composite material has a poor wettability which is beneficial to its lifetime.(5) Application of modified antimony trioxide compound aluminum hydroxide in PVC/Salix powder composite materialSince Antimony trioxide has high cost in mass production, the experiment use aluminum hydroxide to compounding flame retardant. The result was that a small amount of aluminum hydroxide compounding antimony trioxide may repel flame in PVC/Salix powder composite material. By measuring the oxygen index, however, the effect is just in general and aluminum additive amount is large which would be affect material mechanic properties. It is no denying that the complexing aluminum hydroxide can still reach the flame retardant grade and reduce the cost. SEM show the carbon residue layer is thin, FTIR show there is dehydration reaction in flame process.(6) Application of modified antimony trioxide, aluminum hydroxide and TCEP complexing in PVC/Salix powder composite materialAlthough the aluminum hydroxide cost less, the effect is general. TCEP is not only good flame retardant effect but has less influence to the mechanical properties. SEM showed the coke layer after combustion is dense by adding this complexing flame retardant, which can prevent fire spreading effectively.