Preparation And Properties Of Polysulfone Amide/polyphenylene Sulfide High Temperature Composite Filter Felt

The rise of urbanization is generally accompanied by the emergence of air pollution.Fine particulate matter(PM)in the air,especially particulate matter with an aerodynamic diameter less than 2.5 μm(PM2.5),will not only cause frequent haze weather we are familiar with,but also pose a great threat to human health,especially respiratory system.The filter material is the core component of the filter device.With the continuous upgrading of pollutant emission and treatment requirements,the importance of the filter material is becoming increasingly prominent.Nonwoven material plays an irreplaceable role in it because of its superior performance.Polyphenylene sulfide(PPS)needled felt filter material is one of the most chemically stable and cost-effective materials for removing pollutants from high-temperature exhaust gases of metallurgical kilns,power plant boilers and cement production lines.However,the traditional PPS needled felt has great disadvantages.The coarse fiber and large pores lead to its poor ability to capture fine particles,and it is easy to be oxidized in the high temperature environment with high oxygen content,which leads to the decrease of mechanical properties and the reduction of service life.It is an urgent problem to further improve the filtration performance and oxidation resistance of PPS needled felt,which affects the application and development of PPS needled felt in high temperature filtration field.At present,electrospinning technology has become an effective means to prepare nano-sized fiber filtration membranes.With nano-sized fibers and porous structure,electrospinning fiber membranes have high filtration efficiency for fine particles,but there are still some deficiencies in mechanics,including low tensile strength and tear resistance.Aiming at the existing problems of PPS needled felt,the following work was carried out in order to improve its filtration performance and oxidation resistance:Firstly,Polysulfon amide/Polyphenylene sulfide(PSA/PPS)composite filter material with micro/nano structure was prepared to improve the filtration performance of PPS needled felt.By changing the parameters of electrospinning and environmental factors,the best process for preparing PSA nanofibers was selected.This paper provides an efficient method to prepare PSA nanofibers with good morphology and uniform diameter,that is,when the solution mass concentration is 10 wt%,the ambient humidity is 30%,the spinning distance is 20 cm,and the spinning voltage is 25 k V,the PSA nanofiber membrane with the best morphology and uniform diameter can be obtained.Then the hot pressing process was explored and the PSA nanofiber film spun with different liquid quantities and PPS needled felt were hot pressed together by the optimal hot pressing process.After the composite of PSA nanofiber membrane,the filtration performance of PPS filter felt was greatly improved,the pore size and air permeability were reduced,the mechanical properties were slightly improved,and the thermal stability was excellent.The filtration efficiency of 1 m L PSA/PPS composite felt for 1.25 μm Na Cl and DEHS aerosol particles was 99.38% and 100%,respectively.In order to evaluate the advantages and disadvantages of composite filter media,it is found that it has the advantages of high filtration efficiency and low resistance by comparing it with commercial products.At the same time,in the direction of improving the oxidation resistance of PPS needled felt,inorganic nano silica sol was used to modify the fiber surface of PPS needled felt.It was found that the uniform nano coating could effectively improve the oxidation resistance of the filter felt,reduce the pore size and air permeability,and enhance the filtration performance.On this basis,Polysulfon amide/Polyphenylene sulfide(M-PSA/PPS)and Polytetrafluoroethylene/ Polyphenylene sulfide(M-PTFE/PPS)composite filter materials were prepared.It was found that M-PTFE/PPS had the best filtration performance,and the filtration efficiency of 0.225 μm DEHS and Na Cl aerosol particles reached 99.41% and99.72%,respectively.