Synthesis And Application Of Four Armed Sulfamide Halogen-free Flame Retardants

Engineering plastics have good mechanical properties,durability,corrosion resistance,heat resistance and other performance aspects,furthermore,it also have more convenient machining ability.With these advantage mentioned above,it are widely used in electronic electric,automobile,building,office equipment,machinery,aerospace and other industry.Thereinto,polycarbonate?PC?which have been one of the fastest growing engineering plastics in the world by virtue of its excellent performance.But in flame retardance,although PC can achieve UL94 V-2 rating and limiting oxygen index is 26%,but it is still difficult to meet their application needs.Therefore,developing efficient and environmental friendly halogen-free flame retardant is very important to break through the bottleneck of materials application.Adamantane also have superior performance and hailed as a new generation raw material of fine chemical engineering.In view of the four tertiary hydrocarbon on adamantane are easy to react,and form a series of derivatives which have both advantage of adamantane and introduced group.In this paper,a kind of flame retardant that four substituted,high flame retardant elements content and with adamantane as core has been designed and synthesis to enhance the thermal stability and make flame retardant have high dispersity in PC substrate by high rigidity and fat soluble of adamantane,the polar group-NH₂ also improve the compatibility between FRSN and PC.Utimately,more excellent flame retardant performance will be achieved.The specific content of this paper is as follows:1.1,3,5,7-tetra?phenyl-4-sulfonamide?adamantane?FRSN?that four armed sulfamide S/N composite flame retardant is synthesis from adamantane through four-step reactions of bromination,friedel-crafts alkylation,sulfonation and amination.The structure of all intermediate products were characteristic by FT-IR spectra,¹H-NMR spectra and elemental analyses.the synthesis of FRSN was confirmed.2.Mixed FRSN with PC through banburying and then the obtained mixtures were made to standard splines by hot-forming,the combustion performance of samples was tested.The result shows that addition of FRSN around 0.1 wt%could make PC composites pass UL-94 V-0 rating,and LOI value achieve 33.7%.Compared with the commonly used sulfonate flame retardant such as KSS-2 which the market guidance addition is 0.2%to 0.3%,when the addition of KSS-2 is 0.1 wt%,it can't attain excellent flame retardation as FRSN.Through notch impact test and SEM of fracture surface,it shows that-NH₂ of FRSN make it more compatible with PC.3.Cone calorimeter test has been measured to simulate that PC composites combustion under real fire hazard,then combined with FTIR and SEM photos of residual char after combustion,the combustion behavior and mechanism of PC composites have been discussed and TGA test was measured to analysis its thermal degradation behavior.The results show that the TTI,THR,SPR of composite have been reduced.The char after burning is more fluffy and can better insulate oxygen and heat.The SO₂ produced by FRSN promote PC crosslinking into char and N₂ released from FRSN make it fluffy.Calculated by Kissinger method,verified it thermal degradation behavior.