Preparation Of Polyurethane Electret Nanofibers And Application Of Anti-haze Screens

Human activities?such as transportation,industry and agricultural production?produce a lot of pollution.PM2.5 in the air has become one of the most serious environmental pollution problems.Aiming at the problem of air pollution at present,polyurethane?PU?ultrafine nanofibers were prepared by electrospinning technology.Based on the improvement of surface potential and anti-ultraviolet aging property of PU nanofibers,the application potential of PU nanofibers in anti-fog and haze nanofibers window yarns was discussed.The specific work is as follows:In order to prepare ultrafine nanofibers,PU/LiCl ultrafine nanofibers were prepared by electrospinning with lithium chloride?LiCl?added to the polymer PU matrix.The effects of LiCl content on the structure and properties of PU nanofibers were further analyzed.The results show that the diameter and morphology of PU nanofibers become finer and more uniform by adding appropriate LiCl.PU/LiCl nanofibers show good spinnability.When the content of LiCl is 0.3 wt%,the diameter of nanofibers is the smallest?154nm?,the morphology is the most uniform,the mechanical properties of fiber membranes are the best?breaking strength20.74MPa,breaking elongation 175.24%?and the filtration performance of fiber membranes is the best?filtration efficiency 82.217%?.The filtration resistance was27.05 Pa and the quality factor was 0.0635.In addition,the filtration performance of PU/LiCl nanofiber membrane was further studied.It was found that the optimum weight of PU/LiCl nanofiber membrane was 1.74g/m².In order to obtain nanofibers with higher filtration efficiency,PU electret nanofibers were prepared by doping silicon dioxide?SiO₂?electret particles in the spinning solution,and the effects of SiO₂ content on the structure and properties of PU nanofibers were further analyzed.The results showed that the surface potential and filtration efficiency of PU nanofibers were increased by doping appropriate amount of SiO₂.When the content of SiO₂ was 5 wt%,the diameter of nanofibers was 142 nm,the morphology of the fibers was uniform,the average pore size of the fibers was the smallest?average pore size was 1.39 um,porosity was 85.7%?,the mechanical properties of the fibers were improved?breaking strength was 21.85MPa,breaking elongation was 128.73%?and the fibers remained stable after 15 days,With a surface potential of 1.66 KV?test time 15 days,initial potential 4.28 KV?,the filtration performance of the fiber membrane was the best?filtration efficiency94.256%,filtration resistance 29.71 Pa,quality factor 0.0962?,and the optimal weight of the fiber membrane was 1.74 g/m².In order to improve the ultraviolet resistance of the prepared nanofibers,PU anti-ultraviolet aging nanofibers were prepared by doping composite anti-ultraviolet aging agent?UV1/AN-1135?into the spinning solution,and the effects of UV1/AN-1135 content on the structure and properties of PU nanofibers were further analyzed.The results show that doping UV1/AN-1135 improves the anti-ultraviolet aging properties of PU nanofibers;when the content of UV1/AN-1135 is 1 wt%,the diameter of nanofibers is the smallest?135nm?,the thickness of fibers is the most uniform,the fibers can absorb most ultraviolet rays,the transmittance of fibers is over 80%,the mechanical properties of fibers are improved?breaking strength 23.80MPa,breaking elongation 120.10%?and the filtration performance of fibers is the best.?filtration efficiency 97.195%,filtration resistance 30.86 Pa,quality factor0.1158?.After ultraviolet aging treatment,the fiber membranes with UV1/AN-1135content of 1 wt%still maintained the highest tensile strength?21.61MPa,115.035%elongation at break?and the best filtration performance?96.925%filtration efficiency,30.66 Pa filtration resistance and 0.1136 quality factor after aging?.In addition,on the basis of the above experimental research,the anti-ultraviolet aging window yarn of polyurethane electret nanofibers was prepared by needle-free electrospinning machine and hot melt adhesive compound machine.It can be seen that the nanofibers with high surface potential and anti-ultraviolet aging properties are excellent air filtration materials and have great potential in the field of air filtration.