Structural Design And Properties Of Polysulfonamide Fiber-based Porous Materials

Polysulfonamide?PSA?is a kind of high-performance fiber with independent intellectual property rights in China.The existing research mainly processes it into textiles,yarns,paper-based materials,honeycomb materials,etc.and applies them into flame-retardant protection,high-temperature filter electrical insulation,aerospace and other fields.However,most of the current research is still based on existing materials or mature applications,and few of them are used in other fields.Due to the advantages of high porosity and large pore volume,three-dimensional porous materials have received more and more attention in various application fields,and polymer-based porous materials are increasingly valued by researchers because of their excellent performance.Therefore,this thesis aims to explore the structural characteristics of the PSA material,prepare three kinds of porous materials,study its basic properties,and expand its application fields.In recent years,due to the development of the printing and papermaking industry,the water pollution containing dyes has great harm to human health,so its treatment is especially important.The PSA is rich in amide groups and benzene ring groups,which can form various forces with the dyes molecules in the wastewater,thereby achieving the purpose of removal.Therefore,this thesis attempts to apply the polysulfonamide-based materials to the treatment of dye-containing wastewater,and uses methyl orange and rhodamine B aqueous solutions as simulated pollutants to study its adsorption effect on dye contaminants and its mechanism of action.The main research contents are as follows:?1?Structural design and properties of PSA fiber paper-based materials with different fiber to pulp ratios.Using polysulfonamide fiber and pulp,mixed with each other in different proportions,formed into paper by traditional papermaking process,and then subjected to hot pressing treatment to prepare PSA-based porous material.Testing tensile strength,tear strength,elongation,porosity and other indicators are used to characterize the difference in the structural difference of the PSA paper-based materials with different raw material ratios and their mechanical and insulating properties.The results show that the tensile strength and elongation of the paper decrease with the increase of the fiber ratio,while the tear strength and porosity increase with the increase of the fiber ratio.The best overall performance is paper with a fiber to pulp ratio of 6:4,showing good mechanical strength.The performance values were tensile index 35.7 N·m/g,tear index 42.1 mN·m²/g,elongation 8.38%,and porosity 31.05%.Adsorption studies were selected for paper-based materials with the best overall performance.The optimum adsorption capacity of methyl orange and rhodamine B aqueous solution was 61.24 mg/g and 85.92 mg/g,respectively,which shows a certain adsorption capacity.?2?Study on the construction,thermal insulation properties and adsorption properties of PSA fiber-based aerogel materials with different molecular concentrations and crosslink density.Since the PSA paper-based material has a low porosity and is used as an adsorption field,the exposed active sites are limited,so it is necessary to increase the porosity and then apply it.This paper is use PSA fiber as raw material,dimethyl sulfoxide as solvent,tetrabutylammonium fluoride trihydrate?TBAF·3H₂O?as cross-linking agent to prepare PSA-based aerogel porous material,and its compressive strength and porosity structure,thermal insulation properties and adsorption properties were explored.It was found that the fluoride ion in tetrabutylammonium fluoride trihydrate forms a hydrogen bond with the amide group on the molecular chain of the PSA during the preparation to form a three-dimensional network structure aerogel.The compressive strength increases with the concentration of the PSA fiber and the ratio of tetrabutylammonium fluoride trihydrate,wherein the PSA concentration is 6%,and the optimum compressive strength is 1.39 MPa when the amount of TBAF·3H₂O is 2%.The porosity of the obtained aerogel was as high as 80%or more.The optimum adsorption amounts of methyl orange and rhodamine B aqueous solutions were 121.49 mg/g and 157.34 mg/g,respectively,which were significantly improved compared with the adsorption amount of paper-based materials.?3?Preparation and adsorption properties research of composite aerogel porous materials with different mass ratios of PSA fibers and graphene oxide.Due to the strong hydrophobicity of the PSA aerogel,it is easy to float on the water surface when it is used to treat pollutants in water,which reduces its adsorption efficiency.Therefore,it needs to be treated to improve the hydrophobicity of the aromatic sulfone aerogel in the adsorption field.In this thesis,hydrophilic graphene oxide and polysulfonamide were physically blended to prepare four different mass ratios of polysulfonamide/graphene oxide composite aerogel.The structural characteristics,mechanical properties and adsorption properties were characterized.By testing the compressive mechanical properties of the composite aerogel,it can be found that the compressive strength at 70%deformation decreases with the increase of graphene oxide content;and the addition of graphene oxide can effectively improve the hydrophilicity of the aerogel.Its contact angle dropped from 95°to 46°.Based on the compressive mechanical strength and contact angle of the bonded materials,a composite aerogel with a mass ratio of sulfonamide to graphene oxide of 5 was selected for the preliminary study of the adsorption properties of the two dye molecules.The results showed that the addition of graphene oxide After that,the adsorption properties of the materials for methyl orange and rhodamine B increased more than twice,and four time more than PSA paper materials.