Method for preparing temperature-sensitive polyvinylidene fluoride intelligent membrane material and its product

Abstract

This invention relates to a method for prparing temperature-sensitive polyvinylidene flourine intelligent membrane. The method is: NIPA as grafted monomer, PVDF as macromelocular initiator, cuprous chloride as catalyst,4,4 demethyl 2,2 bipyridine as ligand, using atom transfer free radical process, preparation of temperature-sensitive polyvinylidene flourine intelligent membrane comprising: in reaction kettle, adding 7-13% PVDF(WT%) and solvent N-methyl-2-pyrrolidone,heating to 50 deg. C to make it solve completely; then adding grafted monomer NIPA, its mol ratio with cuprous chloride is 2000:1-2500:1,filling nitrogen gas 30mins. at stirring, and separately adding 0.20-025g ligand 4,4-dimethyl 2,2-bipyridine and 0.04-0.06g catalyst cupous chloride, stirring and heating to 80-120deg.C,constant reaction 19-25 hrs; then washing reaction product using pure water to obtain light brown solid, filtering and 80 C degree drying to obtain finish product.

Description

technical field [0001] The invention relates to a membrane material preparation method and product technology, in particular to a temperature-sensitive and temperature-responsive N-isopropylacrylamide (NIPA) graft copolymerized with polyvinylidene fluoride (PVDF) The preparation method and products of type polyvinylidene fluoride intelligent membrane material belong to the field of functional polymer materials, and the international patent classification number is proposed to be Int.Cl 7 C08F 20 / 54. Background technique [0002] Membrane is the core of membrane technology. The chemical properties of the membrane material and the membrane structure play a decisive role in the membrane separation process. Membrane materials must have the following basic functions: good selective permeability; certain hydrophobicity or hydrophilicity; excellent chemical resistance and biodegradation resistance, which can be used for a long time without deterioration; good heat resistance; M...

AI Technical Summary

Problems solved by technology

[0009] In the prior art, the method of PVDF surface modification is used to prepare PVDF smart membranes. The disadvantage is that the grafted polymers are easy to fall off. Reduce the flux of the membrane and change the filtration level of the original membrane

The phase transition method is used to prepare PVDF smart membranes. Although parameters such as PVDF membrane pore size and porosity can be controlled by conditions such as stock solution concentration, coagulation bath, and temperature, when preparing PVDF graft copolymers, the reaction conditions, grafting rate, etc. , the molecular structure and molecular weight are difficult to control, so it is very difficult to study the swelling degree of PNIPA and the change of membrane pores

The applicant's previous patent application (200410019992.9) also involves the preparation method of temperature-sensitive PVDF smart film, but this method also has the problem that the smart layer is easy to fall off.