Novel N-Phosphorylated Iminophosphoranes as Efficient Flame Retardants in Epoxy Resins and Composites

Increasing applications for fiber-reinforced composites lead to increasing demands on properties and attributes. With composite application in for example automotive, electrical and electronical industries, especially the demand on flame-retardancy is increasing. sufficient to just simple add flame retardants, because of a raising demand from government and industry for recyclability, durability and reduced environmental impact. With phosphorous compounds a wide range of flame retardant mechanisms can be observed.2,3Depending on the chemical environment different phosphorous compounds can either interact in the condensed phase as a charring agent or have a gas phase activity similar to the radical scavenging mechanism of halogen containing flame retardants. Also the synergy of phosphorus- and nitrogen-containing flame retardants is well-known. Herein we describe new phosphorus based compounds containing nitrogen-bridged phosphorus units with different chemical environments, tailormade for the relevant application. Besides on highly efficient flame redardancy this work is focusing on liquid phosphorous compounds. These flame-retardant liquids are more suitable for the injection molding technique to manufacture fiber-reinforced composites.