Preportion And Properties Of Antibacterial Melt-blown Polyetnylene Microfiber And Its Aggregate

Since the outbreak of COVID-19 epidemic,melt-blown fiber has been widely used in the fields of medical and health materials such as masks and protective clothing because of its good filterability,good air permeability and low cost.At present,polypropylene（PP）is the main raw material used in melt blowing.However,compared with PP,polyethylene（PE）has better aging resistance,thermal conductivity and flexibility.It has become a research hotspot to learn from the molding idea of melt-blown PP to develop PE melt-blown products.In addition,during the actual use of melt-blown products,bacteria and viruses are blocked on the surface of melt-blown fibers,but they can still survive for several days,which may lead to the problem of secondary infection.Therefore,it is very important to sterilize melt-blown fibers while filtering bacteria.In order to develop PE melt-blown products and endow melt-blown fiber with antibacterial properties,the conditions of melt-blown PE material with high melt-melted fingers were explored.And by introducing Cu₂O,Cu₂O@HNTs as antibacterial agents,give PE melt-blown fiber excellent antibacterial properties.Through the systematic study of resin and melt-blown fiber,it provides theoretical support for the application of antibacterial PE melt-blown microfiber.The main contents are as follows:1.In order to develop PE melt-blown fibers,the properties of four PE melt-blown materials were analyzed,and the influence of process parameters on the structure and properties of melt-blown fibers was explored,and the melt-blown process conditions were optimized.Compared with resins with melting fingers of 390（D-PE-390）and 50（PE-50）,the two PE resins with melting fingers of 120（PE-120）and 735（PE-735）have higher crystallinity,crystallization rate and degradation rate.With the increase of hot air frequency,the diameter and pore diameter of PE melt-blown fibers decrease rapidly,and the breaking strength,filtration efficiency and ventilation resistance of the fibers increase rapidly.However,if the hot air frequency is too high,"flying flowers"will appear,and the quality factor will decrease,which indicates that its comprehensive filtration performance will decrease.With the increase of the rotational speed of melt pump,the diameter and pore diameter of PE melt-blown fiber increased,the filtration efficiency and ventilation resistance increased slightly,but the quality factor decreased rapidly.With the increase of the receiving distance,the diameter of melt-blown fiber decreases slightly,but the pore diameter increases and the breaking strength decreases rapidly,which in turn reduces the filtration efficiency and ventilation resistance of melt-blown fiber.Therefore,the optimized process conditions are:hot air frequency 36 Hz,melt pump speed 200 RPM,and receiving distance 20 cm.2.In order to endow melt-blown fibers with antibacterial properties,PE/Cu2O composite melt-blown fibers were prepared and their properties were studied.Firstly,the composite resin was prepared by melt blending method,and the PE/Cu₂O composite melt-blown fiber was prepared by using the optimum process conditions.The thermal stability and fluidity of the composite resin increased obviously with the increase of Cu₂O content.The addition of Cu₂O makes the crystallinity of melt-blown fiber increase at first and then decrease,but it has no effect on its crystal structure.When Cu₂O content is low,the melt flow increases and the diameter of composite melt-blown fiber decreases due to the decrease of resin viscosity.However,with high addition,Cu₂O tends to agglomerate,which leads to the decrease of spinnability and fiber-forming continuity of melt-blown fibers,and the increase of fiber diameter.The pore size change of PE/Cu₂O composite melt-blown fiber is the same as the diameter,showing a trend of first decreasing and then increasing,which leads to the filtration efficiency and ventilation resistance of melt-blown fiber first increasing and then decreasing.In addition,the addition of Cu₂O has little effect on the comprehensive filtration performance of composite melt-blown fiber.When the addition of Cu₂O reaches 0.4%,the antibacterial rate of PE/Cu₂O composite melt-blown fiber to Escherichia coli and Staphylococcus aureus can reach over 99%,which indicates that it has good broad-spectrum antibacterial property.3.In order to improve the size and dispersion of Cu₂O and further improve the antibacterial performance,Cu₂O@HNTs hybrid material was constructed,and PE/Cu₂O@HNTs composite melt-blown fiber with excellent antibacterial performance was prepared.With EDTA-2Na as chelating agent,Cu₂O with an average size of 5.5nm was uniformly loaded on Alloxite nanotubes（HNTs）.With the increase of the amount of copper ion precursor,the loading of Cu₂O gradually increases.The antibacterial test of the hybrid material shows that when the contact concentration is 10ug/m L,the antibacterial rate of Cu₂O@HNTs to both bacteria can reach over99.99%.The research of PE/Cu₂O@HNTs composite resin shows that the addition of Cu₂O@HNTs can improve the thermal stability of the resin,but decrease the flow property.With the addition of Cu₂O@HNTs,the crystallinity of melt-blown fiber increased at first and then decreased,but it did not affect its crystal structure.The decrease of the fluidity of the composite resin makes the diameter and pore diameter of PE/Cu₂O@HNTs composite melt-blown fiber increase,which leads to the decrease of filtration efficiency and ventilation resistance of melt-blown fiber.However,the quality factor is slightly improved,which indicates that the addition of Cu₂O@HNTs improves its comprehensive filtration performance.When the addition of Cu₂O@HNTs is 0.4%,the antibacterial rate of PE/Cu₂O@HNTs composite melt-blown fiber to Escherichia coli and Staphylococcus aureus can reach above 99.9%,which indicates that it has excellent broad-spectrum antibacterial property.