Research On The Surface Modification Of Polypropylene Nonwoven And Gas Purification Performance

Combined air pollution composed of volatile organic compounds(VOC),particulate matter(PM),and ozone poses a severe threat to human health.However,the removal mechanism of different types of pollutants is quite different,so it is difficult to achieve the purpose of removing multiple pollutants at the same time by relying on one structure alone.In this study,an air purification material with multiple functional structures of filtration,adsorption,and catalysis was prepared based on the modification of melt-blown polypropylene(PP)nonwoven and applied to simultaneously remove PM,VOC,and O₃.Tertiary amine groups,carboxyl groups,and primary amino groups/secondary amino groups were introduced onto the surface of polypropylene(PP)nonwoven via ultraviolet irradiation grafting and co-deposition method.The results indicated that the tertiary amino-functionalized PP nonwoven(PP-g-DMAEMA)with a positively charged surface showed higher PM filtration,which is 76.4%and the pressure drop only increases by 0.8 Pa.rGO-functionalized PP nonwoven was obtained through a step-by-step modification method concluding the self-assembly process and chemical reduction process.The maximum adsorption capacity of PP-g-DMAEMA/r GO nonwoven for toluene,benzene,and xylene was 51.2 mg g^-1,52.4 mg g^-1,and 49.2 mg g^-1 when the relative weight gain(RWG)of PP-g-DMAEMA/r GO nonwoven was 6.3%,respectively.MnO_x-SiO₂ and MnO_x-?CD catalyst was prepared by reduction reaction using methanol and potassium permanganate as a reactant and doping Si O₂ and?-cyclodextrin(?-CD),respectively.MnO_x-SiO₂/PP-g-DMAEMA nonwoven,MnO_x-?CD/PP-g-DMAEMA nonwoven,and MnO_x/PP-g-DMAEMA nonwoven were obtained by loading MnO_x-SiO₂,MnO_x-?CD,and MnO_x catalyst particle onto PP-g-DMAEMA nonwoven surface via self-assembly method,respectively.The results show that the catalyst/nonwovens composite materials can effectively protect against formaldehyde and ozone pollution.The prepared double-layer functional composite PP nonwoven with adsorption and filtration performance owned good performance of removing aromatic gaseous pollutants and PM filtration using the composite method to combine PP-g-DMAEMA nonwoven and PP-g-DMAEMA/rGO nonwoven.The prepared filter-catalytic double-layer functional composite nonwoven achieved effective protection against various pollutants such as formaldehyde,ozone,and PM.The prepared multi-layer functional composite nonwoven protective material obtained good multi-component pollutant removal performance by composite modified method to combine PP-g-DMAEMA nonwoven and PP-g-DMAEMA/rGO nonwoven and MnO_x-SiO₂/PP-g-DMAEMA nonwoven.The experimental results indicated that the functional particles on the surface of nonwovens were not falling off.The prepared multi-layer functional composite nonwoven protective material has excellent multi-component pollutant removal performance,good air permeability,and safety performance.It has potential application value in personal protection and air purification in confined spaces,which provide the new ideal for the research and development of multifunctional protective materials.