Study On Synthesis Of Di-octyl-phosphinic Acid Through Radical Reaction

In this essay, the synthesis of diocthylphosphinic acids such as di(n-octhyl)phosphinic and its isomer bis(2,4,4-trimethylpentyl)phosphinic acids was mainly investigated, and the analysis method of the products is established. Synthesis methods of compounds containing P-C (carbon-phosphorus) linkage were particularly investigated in this essay. With regard to the technical and economical factors, the radical additions method was chose as main synthesis route. The dioctylphosphinic acids specimens were purified by the method of Cu(II) salt , then reacted with ethyl orthoformate. The new esterified production was determined by the method of GC-MS for calculating yields, and ion fragments corresponding to compounds were analyzed. On the one hand, di(n-octyl)phosphinic acids were prepared and optimized through two radical addition routes, one route in polar solvent, the other in neutral solvent. The factors that affect the reaction were separately inspected: free-radical initiator, reaction temperature, reaction time, reactants mol ratio. â‘  Di(n-octyl)phosphinic acids were prepared by the processes which comprised reacting octene-1 with hypo phosphorus in the presence of peroxide compounds, for example benzoate peroxide. The effects of the factors such as free-radical initiator, reaction time, reactants mol ratio were inspected. The results showed that the yield of di(n-octhyl)phosphinic acids was approximately 60%. â‘¡Di(n-octyl)phosphinic acids were also prepared by the processes which comprised reacting octene-1 with sodium hypophosphite monohydrate in the presence of azo compound for example azobis(isobutyronitrile)(AIBN). The effects of the factors including ree-radical initiator, reaction temperature, reaction time, reactants mol ratio were also inspected. And the results showed that the yield of di(n-octhyl)phosphinic acids was approximately 40%. On the other hand, synthesis of bis(2,4,4-trimethylpentyl)phosphinic acids were investigated in the same routine as di(n-octyl)phosphinic acids, and it gave high yields of mono(2,4,4-trimethylpentyl)phosphinic acids but low yields of bis(2,4,4-trimethylpentyl)phosphinic acids, respectly 70% and 5%. With the change of the factors, such as free-radical initiator, reaction temperature, reaction time, reactants mol ratio, the yield weren't not improved effectively. In the end, some simple hypothesis on reaction mechanism was established for briefly explaining series reactions of radical addition.