Synthesis Of Flame Retardant Auto-filter Paper And Its Enhancing Emulsion

Filter paper is an important part of the filter. The base paper of filter paper is made ofplant fiber pulp with a small amount of organic synthetic fiber, and then impregnated withpolymer resin. The commonly used resins for the filter paper impregnation are thealcohol-soluble pHenolic resin and emulsion-type resin. However, the use of alcohol-solublepHenolic resin for the filter paper impregnation will lead to serious environmental pollutionand safety hazards. With enhancing environmental awareness, the emulsion-type resin,including acrylic emulsion, vinyl acetate and its modified copolymer emulsion, water-basedpolyurethane, water-based epoxy resins and other water-based polymer, has been widely used.However, the poorly fire-retardant performance of the filter paper, resulting in generatordamage, car ignition and other accidents, has attracted widespread attention.In order to improve the flame retardant, this issue focused on the following two aspects.First, the base paper was prepared from the good permeability of mercerized pulp and theflame-retardant fiber via wet molding technology. Secondly, the emulsion resin wassynthesized by the introduction of reactive flame retardant monomer diethyl(acryloyloxyethyl)-pHosphonate\(DEAEP) and macromolecular reactive monomerunsaturated double bonds terminated polydimethyl siloxane (DV-PDMS) prepolymer styrenewith styrene(St) and acrylate monomers according to certain mass ratio. The emulsionscontaining P and Si have excellent mechanical properties and flame retardant property. Thenthe emulsion endowed the papers with excellent mechanical properties and enhanced flameretardancy by impregnation. In this paper, three types of synthetic fibers with excellent flameretardant properties, Aramid K129, Polyoxadiazoles(POD), Polyester fibers(PET) wereadopted. The effect of the flame retardant fiber type, the amount of flame retardant fiber onthe evenness, air permeability performance and the flame retardant property of the base paperwere mainly discussed. The base paper made up of the mercerized pulp and the flameretardant fiber had excellent flame retardant and permeability properties.The enhanced emulsion was characterized by FTIR, TG, SEM and so on. The effect ofthe emulsifier dosage, the initator dosage and the seeded monomers dosage on the retardant properties of the filter paper had been explored. Moreover, the effect of the polymerizationprocesses, the types of the flame retardant monomers and the dosage on the thermaldecomposition of the copolymers had also been investigated. Meanwhile, the flame retardantof filter paper and the flame retardant copolymer were characterized by limiting oxygen indexanalyzer(LOI).The results showed that the polymerization process had an impact on the flameretardancy of the final product, besides the flame retardant monomer species, the flameretardant monomer dosage and the mass ratio of P/Si. Besides, the flame retardant property ofthe phosphorus-silicon-containing copolymer was better than that of thepHospHorus-containing copolymer and the silicon-containing copolymer, and the researchresults indicatesd that there was synergistic effect on improvement of the copolymer when themass ratio of P/Si was up to specific numerical.