Study On The Preparation And Performance Of Halogen Free Flame Retard Ant ABS

The oxygen index of ABS resin is only 17%, flame retardant performance is poor. In this paper, different halogen free flame retardant system MRP/Mg(OH)2 and MRP/NE was used to modification of ABS.In this study, halogen free flame retardant ABS materials were prepared by double screw extruder. The effect of compatibilizer, flexibilizer and ZnO and its surface cladding SiO2 modification on ABS properties were studied. The best flame retardant systems and flame retardant formula were discussed. The performances of modified ABS on the combustion performance, mechanical properties, thermal stability, and rheological properties were evaluated.And microstructures were observed by scanning electron microscopy observation (SEM) and also thermo-gravimetric analysis.Separately using flame retardant MRP and Mg(OH)2, flame retardant agent need to add large quantity and the effect is not obvious. When the dosage of MRP for 20 phr, system of oxygen index increased to 24%, when the Mg(OH)2 dosage for 60 phr, the system of the oxygen index increased to 22.5%. Flame retardant MRP and Mg(OH)2 compound with use, system oxygen index reached 24.5%, vertical combustion to UL94V-0 level, at the same time, impact strength, melt flow rate is relatively stable, therefore, choose 40 phr Mg(OH)2 and 8 phr MRP as MRP/Mg(OH)2 compound with the optimal proportion of the system.Choose 10 phr MRP and 20 phr NE as MRP/NE compound with the optimal proportion of the system. And also discussed the flame retardant synergistic effect of ZnO and its surface cladding SiO2 modification,and also researched the synergy mechanism of ZnO.IR analysis results showed that the surface of modification ZnO formed Si-O-Zn key, and suggested that the surface of ZnO formed SiO2 cladding layer. The results showed that ZnO and its surface cladding SiO2 modification can significantly improve the flame retardant properties of material and the effect of mechanical properties is not obvious. When the adding amount of ZnO is 5 phr, the LOI value of the flame retardant ABS up to36%; When ZnO surface cladding SiO2 content is 5%, the flame retardant ABS LOI value up to 41%. TG analysis results showed that ZnO and its surface cladding SiO2 modification can promote materials into carbon, increase the content of carbon residue, and improve the flame retardant properties.There are some improvements on the mechanical properties of flame retardant ABS with joining compatibilizer and flexibilizer.In the MRP/Mg(OH)2 compound halogen free flame retardant system, the tensile strength and impact strength are enhanced with adding compatibilizer.With the increase of adding amount of flexibilizer, flame retardant ABS material impact strength can rise a few and don not have much influence on flame retardant performence. In the MRP/NE compound halogen free flame retardant system, the tensile strength impact strength and bending strength are increased with add compatibilizer.With the increase amount of flexibilizer, flame retardant ABS material impact strength can rise a few and don not have much influence on flame retardant performence.