Method for preparing polypropylene nanofiber on large scale

Abstract

The invention relates to a method for preparing polypropylene nanofiber on a large scale. The method aims to realize the large-scale preparation of the polypropylene nanofiber. The method has the characteristics of high production efficiency and simple process. The invention adopts the technical scheme that the method for preparing the polypropylene nanofiber on a large scale comprises the following steps in sequence of: (1) after an island phase polymer and a marine phase polymer are mixed, fusing and extruding, and directly cooling and granulating in air, wherein the island phase polymer is polypropylene, and the mass percentage concentration of the island phase polymer is 2.5-25 percent; (2) producing a master batch in the step (1) by using melt-blown equipment to obtain superfine composite fiber; (3) dissolving and removing the marine phase polymer in the superfine composite fiber by using a solvent and obtaining the polypropylene nanofiber after drying; (4) heating and recovering the marine phase polymer / solvent waste solution produced in the step (3) and recycling the solvent and the marine polymer.

Description

technical field [0001] The invention belongs to the field of new chemical fibers and textile materials, and specifically relates to a method for preparing polypropylene nanofibers in batches by combining sea-island composite spinning technology and melt blown technology. The prepared polypropylene nanofibers can be used as upgrades for existing polypropylene fibers product. Background technique [0002] Polypropylene is currently the most used type of plastic in the world, of which more than 50% of the consumption is used in the fiber market and the proportion is expected to increase year by year. Polypropylene has excellent fiber-forming properties and can be prepared into various forms including short filaments, filaments, monofilaments, bulked filaments, tows, yarns, and melt-blown fibers. The fiber industry has become the main growth factor for the polypropylene market. driving force. However, the diameter of polypropylene fibers currently produced on a large scale is ...

AI Technical Summary

Problems solved by technology

Melt-blown technology is currently the largest ultra-fine fiber manufacturing method, which relies on high-speed, high-temperature airflow (often close to the melting point of the polymer) to blow the polymer melt to make it stretch rapidly to obtain ultra-fine fibers. The diameter of sprayed fibers is mostly between 2 and 4 μm, and there are still some difficulties in the preparation of nanoscale fibers

The researchers tried various methods to further reduce the fiber diameter, but the Rayleigh-Taylor instability caused by surface tension occurred in the nanofibers during the melt-blowing process, which caused the fibers to break into spherical particles, and the pure polypropylene melt-blown method prepared nanofibers. The diameter limit has its own theoretical limit

Using the template method to prepare polypropylene fiber has complicated operation steps, high cost, and short length of the prepared fiber, which is only suitable for theoretical research in the laboratory, not suitable for industrial production

The electrospinning method requires thousands of volts or even tens of thousands of volts of direct current high voltage, which requires high conductivity of the solution. Polypropylene is a non-polar polymer with poor spinnability, and there is no suitable solvent at room temperature. High-temperature melt electrospinning has high requirements for devices, which greatly limits its industrial application prospects

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