Study On The Preparation Of Porous Materials Based On Melt-blown Leftover

With the increasing aging of the population and the impact of sudden public health events such as SARS and COVID-19,the global demand for nonwoven materials for medical protection has increased sharply,and the market of melt-blown polypropylene(PP)materials has expanded rapidly.A large number of waste melt-blown materials are generated during the production and use of melt-blown materials,causing serious environmental problems.Thus,the development of green and efficient recycling treatments for the waste PP melt-blown materials has become an important issue for countries and regions throughout the world to address.Three-dimensional porous materials have broad application prospects in many fields due to their high porosity and large specific surface area.Melt-blown PP fibers have the features of tiny fineness,light weight,and high specific surface area,making it a promising framework for three-dimensional porous materials.Therefore,the preparation of porous materials based on melt-blown leftovers was studied as follows:This paper focused on the preparation of three-dimensional porous materials from meltblown leftovers.The preparation process of fiber based porous materials mainly includes the homogeneous dispersion of fibers,the freeze forming of fiber dispersion,and the freeze drying process.The uniform dispersion of fibers is a key factor in the preparation of fiber based porous materials.Therefore,the influence of dispersion medium parameters(surface tension,solubility parameters,viscosity)and dispersion parameters(fiber concentration,dispersion speed,and dispersion time)on the dispersion of melt blown PP fibers was studied in this paper.The experiment shows that with the increase of tert butyl alcohol(TBA)volume fraction,the surface tension and solubility parameters of the dispersion medium decrease continuously,which enhances the wettability between the dispersion medium and melt blown PP fiber,and promotes the dissipation of the surface charge of the fiber.When the TBA volume fraction increases by40%,a good fiber dispersion effect can be achieved.In addition,the speed of fiber dispersion is1000 rpm,and the time of fiber dispersion is 3 h.The addition of polyethylene oxide(PEO)in the dispersion system increased the viscosity of the dispersion,thereby improving the stability of the fiber suspension.On this basis,composite porous materials with micro/nano fiber network structure were prepared.The material forming process was studied,and the experiment found that the addition of melt blown PP fiber could significantly improve the volume shrinkage of PEO aerogel.The prepared composite porous material had a fiber like internal PEO,with a fiber diameter of nano scale,and combined with melt blown PP fiber through physical cross-linking points to form a micro/nano fiber network structure,ensuring good formability of the material.PP/PEO composite porous materials show the characteristics of low density and high porosity.However,due to the low stiffness of melt blown PP fiber,the overall deformation resistance of the material is poor,which has certain restrictions on its practical application.