The Preparation And Application Of Intumescent Flame Retardant With The Synergist Of Lanthanum Chloride And Hybrid With Silica Sol

Intumescent flame has superior retardant properties, in the process of the flame retardant, halogen, low smoke, low toxicity and other features make it popular. It can act on a variety of polymers, such as a variety of plastic products, textiles, cotton fabrics. However, the compatibility problems with the flame base hinde red its further development.The silica made by sol- gel method can achieve a good coverage. During the reaction, it can form a three-dimensional silicon carbon skeleton, which has a good physical support performance, therefore, it can be used as flame retardant good coated media.In addition, studies show that adding a small amount of rare earth metals in intumescent flame retardants can improve flame retardant properties of the medium itself, a rare its special atomic structure, it has a similar catalyst performance.In this paper, the sol- gel method is used to the silica sol. When preparing, the intumescent flame retardant with synergist of lanthanum chloride is added. Based on improving the flame retardant properties of cotton fabrics, the halogen- free, non-toxic, environmentally friendly intumescent flame retardant matrix is used, and in order to make the intumescent flame retardant to play a more significant role as well as reduce the amount added, adding a rare metal lanthanum chloride is tried to play a catalytic role in flame. At the same time, taking into account the issues of IFR adhesion to the substrate, TEOS, which as raw materials is used to prepare sol, which can support intumescent flame attached to the cotton fabric. Using vertical combustion analyzer, limiting oxygen index tester to test the flame retardant properties of cotton fabric, using scanning electron to microscopic the morphology of cotton fabric before and after combustion which flame retardants is used to. Using thermal gravimetric analysis to test the combustion characteristics of cotto n fabric which flame retardants is used and observing the char yield.Based on orthogonal experiment, these several elements of this new type of flame retardant’s importance for retardant effect is studied. The result is that the flame retardant effect’s order of TEOS, p H values of urea, ammonium dihydrogen phosphate, lanthanum chloride, pentaerythritol and the reaction medium primary is: the mass ratio of the flame retardant system of the elements, namely m(monoammonium phosphate): m(pentaerythritol): m(urea) ratio> p H value> flame retardant system / TEOS> lanthanum chloride / flame retardant system.The optimal solution for the preparation of the flame retardant is A3B1C3D4, flame retardant system / TEOS is 30% and the mass ratio of the flame retardant system of the elements is m(ammonium dihydrogen phosphate): m(pentaerythritol): m(urea) = 3 : 2: 1, lanthanum chloride / flame retardant system is 3%, p H of the solution is 6 silicone. The addition of intumescent flame retardant system’s acid source is highest, which is consistent to the fact that acid source acts as the most practical sense in process of expansion of flame retardant; the p H of 6 indicates that in a weakly acidic environment, intumescent flame retardant can achieve the greatest degree of dispersion in the sol. Excellent program of fire retardant for the use of cotton fabrics, cotton LOI value can be increased to 35.6%.By scanning electron, some phenomena can be microscopied. Cotton by 9 # retardant treated, which surface is uniformly coated with a layer of material, the surface of fine cotton fabric flocculent amorphous substance that is fire-retardant material, in the continuous heating process the sheet which is formed by retardant gradually migrate to the surface and the surface of t he carbonaceous layer concentration, resulting in more complete fabric structure. By thermal gravimetric analysis, 9 # sample obtained the highest rate of residual carbon after combustion, reaching 41.58%. This is closely related to protective effect of thermal expansion and a dense layer of flame retardant cotton fabric’s surface, effectively prevent the polymer decomposition.In summary, TEOS formed with pentaerythritol generate a Si-O bond, Si-C bond. The incorporation of La elements contribute to the formation of more dense carbon layer and delay the expansion of the thermal decomposition of polymer materials, effectively prevent the burning and decomposition product and the escape of heat to prevent volatile oxygen to the combustion surface or limit its evaporation rate, while suppressing thermally decomposed of the cotton fabric in the polymer material; the release of ammonia and other flame retardant gas by ammonium dihydrogen phosphate and urea diluted oxygen concentration to achieve significant flame retardant.