The Study On Flame Retardant Epoxy Resin Based On Ammonium Polyphosphate And Metal Salt

Epoxy resin?EP?is widely used in electronics,coatings,composites due to its good electrical properties,mechanical properties,chemical resistance and bonding properties,etc.However,the EP is easy flammable and usually accompanies with a large amount of black smoke and toxic gas when EP suffers from fire.To solve this problem,plentiful efforts have been made to improve the flame retardance of EP.Among them,flame retardant containing phosphorus has become a research hotspot because of its environmental protection and high flame-retardant efficiency.Ammonium polyphosphate?APP?is a common inorganic phosphorus flame retardant due to its high content of flame retardant elements,phosphorus?P?,nitrogen?N?,high thermal decomposition temperatureand low cost.However,it is not an efficient flame retardant for P when it is used alone.To solve the problems mentioned above,the flame-retardant system containing APP and cobalt salt or derivatives have been used to flame retard EP in this work.Then the flame retardancy and mechanical performance of composite have been investigated.1.The flame-retardant EP is prepared by Co?NO₃?₂,APP and EP..The limiting oxygen index?LOI?and the vertical burning test?UL-94?tests results show that LOI of?Co?NO₃?₂+APP?/EP can reach 27%and an pass UL-94 V-1 with the addition amount of Co?NO₃?₂and APP is 5wt%.The cone calorimetry result show that the flame retardant of Co?NO₃?₂+APP can reduce of heat release of EP.However,the introduction of Co?NO₃?₂cannot improve the mechanical properties of EP comparing with APP/EP.The tensile strength of the flame-retardant epoxy resin is 36.6MPa,and the bending strength is 45.2MPa.2.The flame-retardant epoxy resin composite?ZIF-67+APP?/EP was prepared via physical blend using ZIF-67,APP,and epoxy resin.The flame-retardant results showed that the LOI value of?ZIF-67+APP?/EP could reach 28.0%and UL-94 could pass the V-1 rating at a total loading of 5 wt%ZIF-67 and APP.Cone calorimeter?CC?test results showed that the peak of heat release rate of 5?ZIF-67+APP?/EP composite decreased largely.Meanwhile,ZIF-67 and APP can improve the mechanical properties of EP comparing with APP/EP.