Study On High Strength Para-aramid Paper With Combined Antibacterial Activities

Polyp-benzoyl-p-phenylenediamine fiber(hereinafter referred to as paraaramid or aramid 1414)is a high-performance fiber,with high strength and high modulus,high temperature resistance,acid and alkali resistance and light weight and other excellent properties,carbon fiber,ultra-high molecular weight polyethylene fiber known as the world’s three high-performance fibers.Its cost performance is the highest in all high-performance fiber,so it has a wide range of applications in many fields,is currently the largest yield,the most widely used high performance fiber.Para-aramid paper prepared from para-aramid fiber is widely used in aerospace,electrical insulation,rail transit,information communication and other fields.Honeycomb core material made from counterpoint aramid paper has the characteristics of high strength,high modulus,high temperature resistance,light weight,etc.,which is widely used in large aircraft and military aircraft.The aramid paper technology is firmly controlled by Du Pont in the US and banned from sale in China.However,due to the small number of surface-active groups and low bonding strength between fibers,the mechanical strength of paper is quite low,which greatly limits the application of para-aramid paper.Therefore,our country needs to develop aramid paper with independent intellectual property rights to solve the problem of the key material.In this paper,high strength para-aramid paper was prepared by modern wet papermaking technology using para-aramid nanofibers as binder,para-aramid staple fibers and pulp as skeleton materials.The effects of nanofiber shape,length of cut fiber,press process and hot-pressing process on the strength of aramid paper were studied.At the same time,in order to further improve the mechanical strength of the para-aramid paper,a certain amount of enhancer is added to the para-aramid paper to improve its performance.In some special areas of paper antibacterial also put forward certain requirements,therefore,this paper through the antibacterial treatment of paper,have antibacterial function of high strength aramid paper.The results are as follows:1.Para-aramid nanofibers have uniform size,good water retention,easy dispersion,large specific surface area and high surface activity,which can form more contact points,thus forming stronger binding force.The viscosity range of nanofibers used for papermaking is controlled from 2.0～5.0 d L/g.The cutting method of para-aramid fiber is prefered to cut the fiber with radial cutter with neat section and the length is 6±0.5 mm.The addition of 10% pulp can fill the gap of para-aramid paper and improve the mechanical strength and electrical insulation of para-aramid paper.Nano fiber as adhesive added to aramid paper,the addition amount of 40%～50%,the comprehensive performance of the best.The best comprehensive performance of para-aramid paper can be obtained with hot pressing temperature of 250～300 and pressure of 12～14 MPa.℃2.WS-1,LSD-1,JH-1217 three types of reinforcement can improve the mechanical strength of paper to a certain extent.The strength of WS-1reinforced agent increased by 37%,the tensile strength increased by 43%,and the addition amount of WS-1 reinforced agent was the highest among the three kinds of reinforcement agents.When the proportion of LSD-1 reinforcer was1%,the strength,tearing degree and tensile strength were increased by 33% and22% respectively.When JH-1217 reinforced agent was added at 2%,the strength increased by 48%,and the tensile strength increased by 23%.At350～450 ℃,the weight loss of the para-aramid paper with reinforced agent is1%～3%,which is mainly caused by the decomposition of the reinforced agent remaining in the paper.3.The results of antibacterial ring showed that the antibacterial effect of dipping method was better than that of adding method.Both type 1506 antibacterial agent and silver ion antibacterial agent had better inhibition on E.coli and S.aureus.The samples were prepared by dipping method of type 1506 antibacterial agent.The diameter of the antibacterial rings for both E.coli and S.aureus was 18 mm when the additive amount was 0.2%,and the diameter of the antibacterial rings increased gradually with the increase of the additive amount,and the antibacterial effect was better.The diameter of the antibacterial rings for S.aureus reached 24 mm when the additive amount was 0.8%.The diameter of S.aureus inhibition ring is 32 mm.The diameter of antibacterial ring for E.coli and S.aureus was 18 mm when the dosage was 0.2%,and the diameter of antibacterial ring gradually increased with the increase of the dosage,and the inhibitory effect was better.When the dosage was 0.8%,the diameter of antibacterial ring for E.coli was 21 mm,and that for S.aureus was25 mm.