Aminated titanium oxide modified polyimide fiber filter material and preparation method thereof

Abstract

The invention discloses an aminated titanium oxide modified polyimide fiber filtering material. The aminated titanium oxide modified polyimide fiber filtering material is formed by copolymerizing aminated nano titanium oxide, a dianhydride monomer and a diamine monomer, and then electrospinning to form a polyimide fiber non-woven fabric; wherein the copolymerization reaction system comprises the following raw materials in percentage by mass: 1.5 to 2.5 percent of aminated nano titanium oxide, 10 to 15 percent of 2, 3 ', 4, 4'-diphenyl ether tetracarboxylic dianhydride and p-phenylenediamine, 1to 1.5 percent of isoquinoline and the balance of N-methyl pyrrolidone; the preparation method of the aminated nano titanium oxide comprises the following steps: dissolving titanium tetrachloride and gamma-aminoethyl aminopropyl trimethoxysilane in a 50% ethanol solution, dropwise adding a 2mol / L NaOH solution, uniformly stirring, carrying out hydrothermal reaction at 150 DEG C for 6-12 hours, dropwise adding N, N, N '-trimethylethylenediamine, performing standing for aging for 3-6 hours, filtering, washing and drying. According to the preparation method, the modification effect of nano titanium oxide on polyimide from the molecular level is realized for the first time, the prepared filtering material is high in stability and good in mechanical property, durability and weather resistance, and the phenomena of falling and stripping of the nano titanium oxide are avoided.

Description

technical field [0001] The invention belongs to the technical field of polyimide preparation, and in particular relates to an aminated titanium oxide modified polyimide fiber filter material and a preparation method thereof. Background technique [0002] Polyimide refers to a class of polymers containing imide rings (-CO-N-CO-) in the main chain. And excellent mechanical strength, corrosion resistance, high insulation, dielectric constant 4.0 at 103 Hz, dielectric loss only 0.004 ~ 0.007, belonging to F to H, is one of the organic polymer materials with the best comprehensive performance, widely used in aviation , aerospace, microelectronics, nano, liquid crystal, separation membrane, laser and other fields. [0003] As the environmental pollution problems caused by high-temperature flue gas such as industrial flue gas, coal combustion, automobile exhaust, biomass combustion, and metallurgy become more and more severe, high-temperature filtration and dust removal technology...

AI Technical Summary

Problems solved by technology

[0004] The existing polyimide / titanium dioxide composite materials are mainly prepared by mixing nano-titanium oxide with diamine and dianhydride, but nano-titanium oxide does not participate in the polymerization reaction, but is physically blended with polyimide fibers Composite, the bonding firmness is not high, nano-titanium oxide is easy to fall off the surface of polyimide fibers, such as the patent application number CN201710857569.3, which discloses polyimide / titanium dioxide hybrid fibers, using nano-TiO 2 , 4,4'-diaminodiphenyl ether, and pyromellitic dianhydride to produce polyimide / titanium dioxide hybrid fibers, but nano-TiO 2 for physical doping

There is also the method of in-situ precipitation of titanium oxide on the surface of polyimide fiber membrane by using titanium salt, which can improve the bonding strength to a certain extent compared with the conventional physical blending method, but this method is only applicable to the synthesized polyimide fiber membrane. Amine fibers are not suitable for diamine monomers and dianhydride monomers that have not undergone polycondensation reactions, and have limitations in synthesis technology and applications. In addition, this method is essentially physical deposition, and there is no chemical reaction between polyimide and titanium oxide. The cross-linking effect has poor durability and wear resistance. After long-term use, the titanium oxide deposited on the surface will still fall off. Reduce its filtration efficiency, such as the patent application number CN201610050579.1, which discloses a preparation method of a polyimide fiber membrane coated with a titanium dioxide nano-layer, using a titanium compound to treat the polyamic acid fiber membrane, and then heat treatment to produce titanium dioxide Coated polyimide fiber membrane, such as the patent application number CN201710132514.6, discloses a polyimide / titanium dioxide composite fiber and its preparation method and application, using titanyl sulfate solution to impregnate the polyimide fiber, Add ammonia water dropwise to precipitate in situ, and obtain polyimide / titanium dioxide composite fiber after heat treatment

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