A Composite Membrane for Improving the Permeability of Polyamide Nanofiltration Composite Membrane and Its Preparation

Abstract

The invention relates to a polyamide nanofiltration composite membrane and a preparation process thereof. The composite membrane is composed of a non-woven base layer, a polymer mechanical support layer and a modified polyamide active separation layer. The feature of the present invention is that by introducing an inhibitor containing a single reactive group into the organic phase, the inhibitor can only react with polyamine monomers but cannot form a three-dimensional cross-linked structure with it because it has only a single reactive group, It inhibits the growth of polyamide chains and changes the network structure of the polyamide active separation layer; at the same time, the reaction process between the inhibitor and the polyamine monomer will generate hydrophilic groups, thereby changing the chemical properties and surface characteristics of the polyamide active separation layer , and finally greatly improve the brine separation performance of the polyamide nanofiltration composite membrane, that is, the permeation selectivity. The modification method has remarkable effect, does not need subsequent treatment process, and is easy to realize industrial scale-up and large-scale production application.

Description

A composite membrane for improving the permeability selectivity of a polyamide nanofiltration composite membrane and its preparation technical field The present invention relates to a kind of preparation technology of functional polymer membrane, relate more specifically to a kind of high permeability selectivity The polyamide nanofiltration composite membrane and its preparation. Background technique Thin film composite membrane (TFC membrane) with polyamide active layer is one of the most widely used polymer separation membranes. One, generally consists of polyester base layer, microfiltration or ultrafiltration polymer support layer and polyamide active separation thin layer, wherein polyester base layer And the polymer support layer is mainly used to improve the mechanical properties of the membrane, and the polyamide active layer plays the main separation role. dense poly The amide thin layer is formed by the polyamine monomer in the aqueous phase and the polya...

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Problems solved by technology

[0006] In view of the problems existing in the above-mentioned technologies, the present invention provides a method for preparing a polyamide nanofiltration composite membrane with high permeation selectivity, and at the same time improves the water penetration and salt retention performance of the polyamide composite membrane to solve the problem of traditional polyamide nanofiltration composite membranes. One of the main problems with membranes

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