Water Resistant PU / EVOH Nanofiber Filter Made from Aqueous Solution

Abstract

When nanofibers are used for filters, their water resistance is important. We tried to realize the water resistance of nanofibers with ethylene-vinylalcohol copolymer (EVOH) made from aqueous solvent. We also investigated the incorporation of polyurethane (PU) emulsion dispersed in water to improve the adhesion between the nanofibers and the nonwoven fabric of the substrate, and to improve rubber elasticity to the nanofibers themselves. There are few reports on research to produce nanofibers by electrospinning method by combining these two techniques to make the solvent as water as possible. It was possible to realize the nanofiber production of EVOH in a state close to the aqueous system which was difficult up to now by combining with PU. Since PU is excellent in adhesion and firmly adheres to the nonwoven fabric of the base material, peeling of the nanofibers from the base material does not occur, and excellent PM 2.5 particle removal is possible even with very small nanofiber basis weight. Furthermore, it was found that nanofibers can be produced even by using a coil type electrospinning apparatus for industrialization. In the future, to reduce the solution concentration of PU / EVOH to 10 wt%, it is necessary to devise measures such as increasing the hydrophilic component in the structure of PU.