Study On The Synthesis And Flame Resistance Of Novel Intumescent Flame Retardants Containing Phosphorus And Nitrogen

Intumescent flame retardant (IFR) is a kind of composite flame retardant with nitrogen and phosphorus as the main component which is widely used in commodity, electronic appliances, defense industry, transportation, aerospace industry and construction, etc. In this paper a series of novel IFR were synthesized with POCl3, neopentyl glycol and pentaerythritol as the main reagents, and aferwards their properties and application were studied. The main research contents are as follows:1.In this paper, series Intumescent flame retardant were prepared by using neopentyl glycol chlorophosphate as intermediate, ultrasonic technology was used to synthesise neopentyl glycol chlorophosphate, and the effect of ultrasonic on yield was studied., the effect of ultrasonic on yield of products was studied. Taking the synthesis of neopentyl glycol ethylene phosphoramide as an example, the effect factors on yield such as reaction temperature, solvent, acid-binding agent were studied through single factor experiment. Two kinds of novel IFR were prepared by reacting intermediate with benzimidazole and benzotriazole respectively in this paper,and they haven’t been reported previously, then their reaction mechanism was studied.2.1n this paper, another series intumescent flame retardant were prepared by using pentaer ythritol phosphonyl dichloride as intermediate, ultrasonic technology was also used to synthesise pentaerythritol phosphonyl dichloride,and effects of ultrasonic on reaction time and reaction temperature were studied. The optimal reaction conditions of preparation of pentaerythritol double phosphate diethylamine were obtained through orthogonal experiment and as fellows:n (intermediate):n (diethylamine)=1:4, reaction temperature is80℃, reaction time is3h.3.Thermal stability of eight kinds of IFR was tested through TG/DSC, their initial decomposition temperature were obtained as well as the amount of residual carbon. The ability of intumescing into carbon after heated of IFR was obtained through high temperature muffle furnace calcination experiment. The optimal IFR was selected and used to study the effect of synergy of phosphorus, nitrogen and carbon on the ability of intumescing into carbon.4.Three kinds of representative IFR were selected and mixed with polypropylene in different ratio. Their oxygen index, flame retardant efficiency, impact strength, tensile strength were tested and the reason of decreasing in mechanical properties were analysed. Finally the optimal additive amount of flame retardant was obtained after summarizing the above rules. The experiments in this paper have an important guiding significance on the production and application of IFR in future.