Preparation Of Phosphorus-nitrogen Flame Retardant And Its Effect On Flame Retardant Of Epoxy Resin

Epoxy resin?EP?with its stable chemical properties,high mechanical strength and excellent electrical insulation properties is widely used in electronic packaging,automotive machinery,aerospace and other fields.However,as a kind of organic polymer,epoxy resin is flammable and releases a large amount of heat and toxic smoke when burning,which poses a threat to the lives of people in the fire.In order to reduce the fire risk of epoxy resin,it is necessary to conduct flame retardant treatment on epoxy resin.At present,most of the flame retardants applied to epoxy resin are formed by covalent bond,making the preparation process complex and the cost high.Against the covalent bond formation of flame retardants is preparing process is complex,high cost of the problem,this paper from the Angle of the flame retardant molecular structure design,the ionic bonds was used to construct method of flame retardant was prepared by a new type of phosphorus-nitrogen halogen-free flame retardants?P-EDA?,and use the Fourier infrared spectrum?FTIR?,elemental analysis?XPS?,mass spectrometry?MS?test of the flame retardants?P-EDA?had been used to characterize the molecular structure,and the phosphorus-nitrogen flame retardant agent?P-EDA?is applied to the flame retardant modification of epoxy resin,Add P-EDA flame retardants and CuO copper oxide flame retardant association agent preparation of flame retardant epoxy resin material,and through the limited oxygen index?LOI?and vertical burning test,thermogravimetric analysis?TGA?and CONE calorimeter test?CONE?,and other methods,studied the content of P-EDA effect on flame retardant properties of the EP and P-EDA and CuO in synergistic flame retardant effect of epoxy resin,and analyzes the P-EDA flame retardants for flame retardant mechanism of EP.The research results are as follows:?1?The product p-eda was obtained by using phosphoric acid and ethylamine as raw materials and using ionic bond to construct flame retardant.Its functional group was characterized by Fourier infrared spectroscopy?FTIR?.NH₃⁺absorption peak was found at2850 cm^-1,1542 cm^-1,indicating that phosphoric acid and ethylamine had reacted through ionic bond.?XPS?,through the analysis of the element to analyze its phosphorus nitrogen ratio,phosphorus nitrogen ratio is about 1:2.5,through the testing of the mass spectrum?MS?,lost pieces for phosphoric acid,ethylene diamine,all analysis shows that phosphoric acid and ethylene diamine by ionic bonding with phosphoric acid containing phosphorus and nitrogen flame retardant elements/ethylenediamine salt flame retardants P-EDA.?2?The flame retardant properties of flame retardant epoxy resin materials were studied by LOI,TGA,CONE and other methods.The study found that with the increase of P-EDA flame retardant additives and flame retardant performance improved significantly,when adding 20%P-EDA flame retardants of flame retardant epoxy resin materials,limit oxygen index reached 31.5%,vertical combustion grade V-level 0,heat release rate significantly decreased,the peak heat release rate was reduced by 50.7%,smoke generation rate was reduced by 39.5%,carbon dioxide release rate was reduced by 55%,show that the flame retardant epoxy resin has good flame retardant effect.?3?Phosphoric acid/ethylenediamine salt flame retardant p-eda and CuO flame retardant synergism were used to prepare flame retardant epoxy resin materials.The synergism of p-eda and CuO in epoxy resin was studied by LOI,TGA,CONE and other methods.It was found that when 18%p-eda flame retardant and 2%CuO flame retardant synergists were added to the flame retardant epoxy resin material,the ultimate oxygen index reached 31.5%,the vertical combustion grade was v-0,the peak heat release rate decreased by 60.1%,the total heat release rate decreased by 18%,the total smoke generation decreased by 33%,and the peak CO release rate decreased by 40.6%.P-EDA flame retardant and CuO flame retardant synergistic epoxy resin materials have significant flame retardant effect and smoke suppression and poison reduction effect.?4?Through to the pure epoxy resin and heat release behavior of P-EDA flame retardant epoxy resin,thermal degradation behavior,contrastive analysis of the carbon residue morphology,P-EDA flame retardants for flame retardant mechanism of epoxy resin for:P-EDA flame retardants are added,on the one hand makes PO·free radicals in the combustion process,capturing the·OH free radical in the flame and·H free radicals,which interrupt the combustion chain reaction,to realize the gas flame retardant effect of EP,reducing the combustion heat release;On the other hand,the introduction of p-eda flame retardant can decompose and catalyze the formation of carbon in advance during combustion,which improves the integrity of carbon layer and plays the role of condensed phase flame retardant.It can isolate the oxygen and heat from the outside into the internal substrate and reduce the heat and smoke gas released by combustion,thus improving the flame retardant performance.