CN-120401049-B - Adhesive fiber for separation membrane support, preparation method and application

Abstract

The invention provides a bonding fiber for a separation membrane support, a preparation method and application thereof. The polymer monomer of the bonding fiber comprises terephthalic acid, ethylene glycol, maleimide and carbon nano tubes, the PET short fibers are bonded and linked through dynamic covalent bonds to form polyester fibers with larger molecular weight, the dynamic covalent bonds are broken in a heating processing state, the bonding fibers become a plurality of short fibers, the fluidity is increased, the plasticity and the processing are facilitated, the dynamic covalent bonds are restored again when the cooling forming is carried out, the covalent bonds between the short fibers and the carbon nano tubes are bonded again, a compact crosslinked network is formed, and the mechanical property of the integral structure is enhanced.

Inventors

• ZHUANG XUPIN
• Xue Luyun
• LIU YA
• SHI LEI
• XIA LEI
• YANG GUANG

Assignees

• 天津工业大学

Dates

Publication Date

20260512

Application Date

20250428

Claims (9)

1. 1. The bonding fiber for the separation membrane support is characterized in that the polymerization monomer of the bonding fiber comprises terephthalic acid, ethylene glycol, maleimide and carbon nano tubes, and the main chain structure of the bonding fiber is shown as formula 1: Formula 1; Wherein, is the site of dynamic covalent bond connection of the main chain and the carbon nano tube; a is selected from any positive integer of 50-140.
2. 2. The bonding fiber of claim 1, wherein the carbon nanotubes are selected from any one or more of single-walled carbon nanotubes, multi-walled carbon nanotubes, or modified carbon nanotubes.
3. 3. The bonding fiber according to claim 1, wherein the mass ratio of the carbon nanotubes to maleimide is 0.5-1:1.
4. 4. A method of producing a binder fiber according to any one of claims 1 to 3, comprising the steps of: S1, adding terephthalic acid and ethylene glycol into a reactor, adding a catalyst, and heating to react; S2, adjusting the reaction temperature to 160-200 ℃, adding maleimide, and carrying out heat preservation and stirring reaction; And S3, acidizing the carbon nano tube, adding the treated carbon nano tube into a solvent, performing ultrasonic dispersion to obtain a dispersion liquid, adding the dispersion liquid into a reaction product obtained in the step S2, performing heat preservation and stirring reaction, slowly cooling to room temperature after the reaction is finished, adding a polymer precipitate into methanol, performing vacuum drying, and performing melt spinning to obtain the bonding fiber.
5. 5. The method for producing binder fibers according to claim 4, wherein the molar ratio of terephthalic acid to ethylene glycol is 1:1.2-2.
6. 6. The method for producing a binder fiber according to claim 4, wherein the heating temperature in the step S1 is 200 to 250 ℃.
7. 7. The method for producing a binder fiber according to claim 4, wherein the holding time in step S2 is 1 to 2 hours.
8. 8. The method for producing a binder fiber according to claim 4, wherein the reaction temperature of the heat-retaining stirring reaction in step S3 is 150 to 200℃and the reaction time is 1 to 4 hours.
9. 9. Use of a binding fiber according to any one of claims 1 to 3 or a binding fiber prepared by a method according to any one of claims 4 to 8 in a support for a separation membrane.

Description

Adhesive fiber for separation membrane support, preparation method and application Technical Field The invention relates to the technical field of separation membrane supports, in particular to a bonding fiber for a separation membrane support, a preparation method and application thereof. Background With the rapid development of membrane separation technology, separation membranes are widely applied to various fields such as sea water desalination, wastewater treatment, biomedical treatment, petrochemical industry, food and beverage processing and the like. The structure and performance of the separation membrane support are subject to higher requirements. The existing preparation technology of the separation membrane support body generally adopts low-melting-point Polyester (PET) fiber or other low-melting-point bonding substances as a bonding agent, can be melted at a lower temperature, is convenient for forming a uniform bonding layer among the fiber or particles, permeates into a microporous structure of a matrix material, and forms a solid fiber network after cooling, thereby enhancing the overall thermal stability and mechanical strength. However, the low-melting-point bonding component is easy to generate thermal deformation in the drying process and the later high-temperature use environment, so that the use effect of the whole separation membrane is affected. For example, the low melting point characteristic still causes local melting, shrinkage or morphological change in a high-temperature environment, thereby affecting the stability and pore structure of the separation membrane support, the control of melting and cooling rates of bonding fibers in the drying or solidification process is very critical, uneven bonding among fibers can be caused by too high or too low speed, weak connection points can be formed, and under some high-temperature operation conditions, such as long-time exposure in a high-temperature medium in the separation process, the bonding fibers can be gradually degraded due to repeated thermal circulation, the mechanical property and separation effect of the whole structure are reduced, and the like. Particularly, high-temperature resistant separation membranes are needed in the high-temperature filtration fields (such as textile printing and dyeing wastewater treatment, fruit juice purification, boiler water treatment and the like), and most of the separation membrane supports on the market at present can only be used at lower temperature, so that the development of the high-temperature resistant separation membrane supports has important significance. Disclosure of Invention The invention aims to provide a bonding fiber for a separation membrane support, a preparation method and application thereof, which improve the crystallinity of the bonding fiber after processing and ensure the mechanical performance and separation effect of the whole structure in a high-temperature environment. The technical scheme of the invention is as follows: In a first aspect, the present invention provides a binder fiber for a separation membrane support, the binder fiber having polymerized monomers including terephthalic acid, ethylene glycol, maleimide, and carbon nanotubes. Further, the main chain structure of the bonding fiber is shown as formula 1: Wherein, is the site of dynamic covalent bond connection of the main chain and the carbon nano tube; a is selected from any positive integer of 50-140. The numerical value of a directly influences the molecular weight of the bonding fiber after chain breakage, the smaller the value of a, the lower the molecular weight of the bonding fiber formed after dynamic covalent bond breakage under the heating state is, so that the bonding is convenient, but the too low is not beneficial to processing, and the larger the value of a, the closer the molecular weight of the bonding fiber formed after dynamic covalent bond breakage under the heating state is to the molecular weight of the original PET fiber, so that the bonding is not beneficial to bonding, but the processing is beneficial. Further preferably, a is 100. In some embodiments, the carbon nanotubes are selected from any one or more combinations of single-walled carbon nanotubes, multi-walled carbon nanotubes, or modified carbon nanotubes. The sp 2 hybridized carbon skeleton of the carbon nano tube contains conjugated double bond, and can be used as a diene body or a dienophile body to carry out D-A reaction with double bond on maleimide to form dynamic covalent bond. When the temperature of the dynamic covalent bond is 100-150 ℃ and 150 ℃ or higher, all DA bonds can be broken, the molecular weight and the cohesiveness of the cohesive fiber are reduced, the fluidity is increased, the cohesiveness is increased, after the processing is finished, the carbon nano tube is stretched and cooled, the reaction balance moves towards the addition direction along with the crystallization optimization and the stre