Structure control method of outer surface of polypropylene separation membrane

Abstract

The invention relates to a structure control method of the outer surface of a polypropylene separation membrane. The method comprises the steps that: (1) polypropylene and a diluent are added into a kettle with a stirring device; the mixture is heated and stirred, such that a membrane casting solution is prepared; (2) the membrane casting solution is filtered by using a filter; an inner core liquid is introduced into a spinning nozzle; the inner core liquid and the membrane casting solution are extruded by the spinning nozzle; the mixture is cooled and cured through 0-20 DEG C coagulation bath, such that a hollow fiber membrane is obtained; (3) the hollow fiber membrane is wound by using a winding machine, and is extracted in one or a plurality of extraction agents; and (4) the extracted membrane is fetched and dried; and the extraction agent is removed, such that the polypropylene hollow fiber separation membrane is obtained. According to the invention, variety and temperature conditions of the coagulation bath are improved, such that a problem of polypropylene separation membrane outer surface compact skin is solved. Polypropylene separation membrane porosity is improved from 44% to approximately 70%, and polypropylene separation membrane pore size is reduced from 0.45 to approximately 0.25. The increasing of porosity and the reduction of pore size show that the membrane pores are more uniform, and the probability of large pores is reduced or eliminated.

Description

technical field

[0001] The invention belongs to the field of polymer material science, relates to a preparation method of a polymer separation membrane, and more particularly relates to a method for controlling the structure of the outer surface of a polyolefin separation membrane. Background technique

[0002] A polymer separation membrane is a polymer interface that separates two homogeneous substances. With the development of membrane science and technology, polymer separation membranes have been widely used in water treatment, chemical industry, electronics, steel, medical treatment, food and other industries. As a polyolefin material, polypropylene is a highly crystalline thermoplastic resin polymerized mainly from propylene monomers. It has high transparency, non-toxicity, light specific gravity, easy processing, high impact strength, chemical corrosion resistance, and Flexibility, good electrical insulation and other excellent properties. Due to its excellent perfor...

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