Research On The Flame Retardant Properties Of Self-assembled Paper Products Compounded With Modified Silk Fibroin, Nitrogen And Phosphorus Salts And Silica

Biomaterials have renewable,environmentally friendly,non-toxic,cost-effective,and other features.Thus,they are widely used in various fields.Combined with phosphorus-containing elements,silicon element flame retardants and flame retardant domestic and foreign research status,it is suggested that biological protein materials promote carbon effect,phosphate catalytic carbonization effect,and silicon-based materials.In combination,it is likely to become a new type of high-efficiency flame retardant technology for the production of flame retardant paper.In this paper,the bio protein material was used as the body,which was based on melamine phosphate（MP）and the silica/silicon nitride（Si O₂/Si₃N₄）flame retardant system,and the construction of biological protein-based expansion flame retaining system was deployed on the surface of the paper article.After contrast analysis,the optimal biological protein material flame retardant mechanism was studied and studied from two aspects of industrial performance.In order to study whether the biological protein material has flame retardant effect on paper,eggshell powder（EP）was modified with Al SO₄,and a flame retardant system was constructed with MP to coat the surface of paper products firstly.The results showed that calcium carbonate and a small amount of protein in EP play a certain flame retardant role.Secondly,the ovalbumin（CO）was modified with an environmentally friendly neutral salt solution NH₄Cl,supplemented by MP and Si₃N₄to construct a nitrogen-phosphorus-silicon flame retardant system,and a flame retardant paper product was prepared by coating method.The results showed that more protein in CO enhanced the flame retardant effect of nitrogen-phosphorus-silicon flame retardant system.In order to further enhance the flame retardant effect of biological protein on paper products,soybean protein isolate（SPI）was modified with D-fructose,supplemented with MP and Si₃N₄ to construct a nitrogen-phosphorus-silicon flame retardant system,and the flame retardant system was prepared by coating paper.The results showed that the modified SPI flame retardant paper products had excellent flame retardant properties.Finally,based on the research of three biological protein-based flame retardant paper products,in order to further improve the flame retardant properties of paper products,cationic cellulose（JR-400）was designed to modify silk fibroin（SF）,supplemented with MP and Si O₂ to construct a nitrogen-phosphorus-silicon flame retardant system for assembly on the surface of paper products.The results showed that the flame retardant paper products of the modified SF coating group have the best flame retardant effect.In order to explore the synergistic effect of nitrogen-containing phosphorus salts and silicon-based materials in the flame retardancy of paper products,MP and Si O₂were used to coat the surface of paper products separately and combination.The results of vertical fire test（VFT）showed that the flame burning time of the MP-coated paper products was shortened significantly,and the flame burning time of the Si O₂ coated paper products was particularly shortened.The mixed-coated paper products combined MP and Si O₂.The advantages of coating paper products were obvious to improve the flame retardant effect.The results of limiting oxygen index（LOI）showed that the LOI value of the mixed-coated paper products was much higher than that of the separately-coated paper products.The carbon-forming ability of MP and the heat-insulating ability of Si O₂ play a synergistic role in flame retardancy.Through the research on the combustion performance of four biological protein-based flame retardant paper products,to further study the flame retardant mechanism of biological protein in the nitrogen-phosphorus-silicon intumescent flame retardant system,the flame retardant performance of SF modified and assembled flame retardant paper and Further exploration of industrial performance.The flame retardant results showed that the increase of the number of assembled layers,the better the combustion inhibition performance,the LOI value was as high as 38%,the carbonization length was only 42%of the untreated sample,the heat release rate,total release heat and CO generation rate were significantly reduced,and decomposition.The temperature and the amount of carbon residue increased.The flame retardant mechanism was mainly that the flame retardant layer released a large amount of non-combustible gas during the combustion process.SF and MP can catalyze the paper fiber to form a rich carbonaceous carbon layer,and Si O₂ blocks the heat and mass transfer between the matrix and the outside world,reducing the risk of fire.The industrial performance results showed that the flame retardant coating had a synergistic effect on the color and luster of the sample,and has a certain influence on the light transmittance.