Preparation,characterization And Properties Of M-aramid-based Composite Membranes With Natural Macromolecule As Porogen

m-Aramid(MPIA)fiber has a series of excellent properties,such as good chemical stability,heat capabilities as well as flame-retardant performance,etc.Besides,m-aramid has flexible and elongated characteristics,so it is often used in making fire fighting clothing or anti arc clothing and so on.However,single m-aramid usually has some defects in using,the air permeability,moisture permeability and water absorbency is poor and can't meet people's requirements for wearing comfort.What's more,m-aramid is often used in wet environment and it was apt to breed bacteria.Based on this,this article attempts to use chitosan and cellulose of the two kinds of natural macromolecules,using solution blending method to prepare a series of m-aramid/chitosan and m-aramid/cellulose blend membranes,then the prepared membranes was degraded by bio-enzymatic,finally the porous m-aramid/chitosan and m-aramid/cellulose blend membranes were obtained.The performance of the blend membranes were tested,compared with pure m-aramid,the air permeability,moisture permeability or water absorption properties have been greatly improved,and the blend membranes has good antibacterial property.The m-aramid and chitosan was dissolved in a DMSO solution to obtain homogeneous m-aramid and homogeneous chitosan solution.Then the two solutions were blended in different ratios and stirred constantly for 2 hours in 60°C followed by film manufacturing on a glass plate.Then a series of m-aramid/chitosan blend membranes were obtained: 100/0,85/15,75/25,65/35,50/50,35/65 and 0/100.Chitosanase,cellulase,papain,lipase and glucose oxidaseby was used to degrade them,respectively.The degradation results showed that chitosanase and cellulase have the best degradation efficiency and the degradation rate can reach to 73%.FT-IR indicated the miscibility of m-aramid and chitosan and the property of blend membranes were stable during the degradation process.SEM indicated that the blend membranes showed a relatively even surface,while the opposite side showed many voids,after degradation,the cross section exhibited a porous network structure.TG analysis showed that the membranes still had good thermal stability after degradation.After degradation,the air permeability,moisture permeability and water absorption of porous blend membranes were all greatly improved than that of pure m-aramid.Besides,pure m-aramid has noantibacterial activity,while the antibacterial activity of porous blend membranes against E.coli and S.aureus can reached 26.56% and 27.33%,respectively.m-Aramid and cellulose was dissolved in a DMAC/LiCl solution,solution blending method was used to prepare a series of m-aramid/cellulose blend membranes:100/0,90/10,80/20,70/30,60/40,50/50 and 0/100.Chitosanase,cellulase,papain,lipase and glucose oxidaseby was used to degrade membranes,respectively.The degradation results showed that cellulase has the best degradation efficiency and the degradation rate can reach to 80%.The FT-IR indicated that the m-aramid and cellulose is miscible and the properties of the membranes were stable during the degradation process.SEM indicated that the blend membranes showed a relatively even surface,while the opposite side showed many voids.After degradation,the surface morphology of the membranes changed greatly and the cross section exhibited a sponge-like porous structure.TG analysis showed that the membranes still had good thermal stability after degradation.Compared with pure m-aramid,the air permeability,water vapour transmission rate and water absorbency were all improved greatly.After a simple bleach process using NaClO,the porous m-aramid/cellulose materials showed sufficient antimicrobial efficacy against Escherichia coli(Gram-negative)and Staphylococcus aureus(Gram-positive).