A novel photo-initiated approach for preparing aluminum diethylphosphinate under atmospheric pressure

A novel preparation of aluminum diethylphosphinate（AlPi） was carried out with free-radical addition reaction by means of UV-irradiation under atmospheric pressure.A solution of sodium hypophosphite was treated with ethylene and irradiated with ultraviolet light in the presence of an amount of photoinitiator effective to initiate the free-radical reaction between the hypophosphite anion and the double bond of the ethylene molecule.The ethylene was micro-bubbled into the reaction mixture with the addition of the photoinitiator,and the gas-liquid contact surface and the photoinitiator concentration in the gas-liquid interface were increased largely.The yield of the final product could be improved to about 96%.The contents of P,Al in samples were detected by ICP,and the molecular structure of the samples was confirmed by ~（31）P NMR,~1H NMR and FTIR spectroscopic analysis.Thermal stability of the final products was investigated in detail by TG-DTA.