阅读说明：本技术 多孔纤维及其制备方法和应用 (Porous fiber and preparation method and application thereof ) 是由 江冰 张涛 赵燕 于 2020-05-18 设计创作，主要内容包括：本发明涉及一种多孔纤维的制备方法,包括以下步骤：将油相加入水相中,均匀混合后得到水包油型乳液,其中,所述油相为多巯基化合物的有机溶液,所述多巯基化合物为含有2～8个巯基的小分子化合物；所述水相包括水溶性乳化剂、水溶性聚合物和水,所述水溶性聚合物的分子链中包括2～4个丙烯酸酯基或丙烯酰胺基；所述油相与水相的体积比为2:1～6:1；将所述水包油型乳液作为纺丝原液并挤入凝固浴中,进行湿法纺丝,所述纺丝原液中多巯基化合物和水溶性聚合物发生界面聚合反应,反应完全后得到所述多孔纤维。本发明的多孔纤维可用于水、多种有机溶剂和重金属离子的快速吸收,该种制备方法实现了多孔纤维连续生产。(The invention relates to a preparation method of porous fiber, which comprises the following steps: adding an oil phase into a water phase, and uniformly mixing to obtain an oil-in-water emulsion, wherein the oil phase is an organic solution of a multi-thiol compound, and the multi-thiol compound is a small molecular compound containing 2-8 thiol groups; the water phase comprises a water-soluble emulsifier, a water-soluble polymer and water, and a molecular chain of the water-soluble polymer comprises 2-4 acrylate groups or acrylamide groups; the volume ratio of the oil phase to the water phase is 2: 1-6: 1; and extruding the oil-in-water emulsion serving as spinning stock solution into a coagulating bath for wet spinning, wherein the multi-sulfhydryl compound and the water-soluble polymer in the spinning stock solution are subjected to interfacial polymerization reaction, and the porous fiber is obtained after the reaction is completed. The porous fiber can be used for quickly absorbing water, various organic solvents and heavy metal ions, and the preparation method realizes continuous production of the porous fiber.)

1. A method for preparing porous fiber, which is characterized by comprising the following steps:

(1) adding an oil phase into a water phase, and uniformly mixing to obtain an oil-in-water emulsion, wherein the oil phase is an organic solution of a multi-thiol compound, and the multi-thiol compound is a small molecular compound containing 2-8 thiol groups; the water phase comprises a water-soluble emulsifier, a water-soluble polymer and water, and a molecular chain of the water-soluble polymer comprises 2-4 acrylate groups or acrylamide groups; the volume ratio of the oil phase to the water phase is 1: 1-6: 1;

(2) and extruding the oil-in-water emulsion serving as spinning stock solution into a coagulating bath for wet spinning, wherein the multi-sulfhydryl compound and the water-soluble polymer in the spinning stock solution are subjected to interfacial polymerization reaction, and the porous fiber is obtained after the reaction is completed.

2. The method of claim 1, wherein: in the step (1), the multi-sulfhydryl compound accounts for 1-15% of the total volume of the oil phase; the multi-mercapto compound is pentaerythritol tetra-3-mercaptopropionate and/or trimethylolpropane tri (3-mercaptopropionate).

3. The method of claim 1, wherein: in the step (1), the water-soluble emulsifier accounts for 2-15% of the total weight of the water phase; the water-soluble emulsifier is poloxamer and/or alkylphenol polyoxyethylene.

4. The method of claim 1, wherein: in the step (1), the water-soluble polymer accounts for 3-30% of the total weight of the water phase; the water-soluble polymer is polyethylene glycol diacrylate, polyethylene glycol-polypropylene glycol-polyethylene glycol diacrylate or polyethylene glycol-polypropylene glycol-polyethylene glycol diacrylate.

5. The method of claim 1, wherein: the molar ratio of sulfydryl in the multi-sulfydryl compound in the step (1) to carbon-carbon double bonds in the water-soluble polymer is 1: 0.9-0.9: 1.

6. The method of claim 1, wherein: in the step (2), the coagulation bath used for wet spinning is an ammonia water solution, and the concentration of the ammonia water in the coagulation bath is 1-15 wt%.

7. The method of claim 1, wherein: in the step (2), the temperature of the coagulation bath used for wet spinning is 0-30 ℃.

8. The method of claim 1, wherein: in the step (2), the spinning speed in the wet spinning process is 30-300 mL/h.

9. A porous fiber produced by the production method according to any one of claims 1 to 8, characterized in that: the diameter of the porous fiber is 100-500 mu m; the fiber is internally provided with communicating pores, the average pore diameter is 5-400 mu m, and the average pore diameter of the communicating pores is 1-50 mu m; the density is 0.1 to 0.5g/cm³。

10. Use of the porous fibre of claim 9 in the preparation of an adsorbent and/or absorbent for one or more of water, organic solvents, organic dyes and heavy metal ions.

Technical Field

The invention relates to the technical field of fiber preparation, in particular to porous fiber and a preparation method and application thereof.

Background

The porous fiber has the advantages of large length-diameter ratio, high specific surface area and the like, so that the porous fiber has important application in the fields of absorption, adsorption and the like. The porosity of porous fibers generally means that there is a void structure between the fibers. In recent years, fibers having a porous structure inside have been successfully prepared by applying new technologies and methods. For example, CN 106894105A uses a ternary system of polyacrylonitrile, dimethyl sulfoxide and pore-forming agent as spinning solution, and prepares a porous polyacrylonitrile fiber by a wet spinning method.

In addition, emulsion wet spinning is a technical method capable of preparing fibers with porous structures. The emulsion wet spinning solution mainly utilizes a water-in-oil or oil-in-water two-phase dispersion system to form an external organic solution continuous phase and an internal aqueous solution continuous phase in the emulsion, and an emulsifier is added to promote the interaction of the continuous phase and the dispersed phase so as to form stable emulsion. For example, in the document "Effect of protein-loading on properties of wet-spun poly (L, D-lactide) multifilamentamide fibers 2010,116(4), 2174-2180", polymer protein emulsion is used as spinning solution and extruded into an ethanol coagulation bath, and the formed fiber has a unique sheath-core structure, a porous inner core and a smooth outer sheath. In the above-mentioned documents, the fibers formed are protein-loaded fibers with low mechanical strength values, tensile strain at break ranging from 60 to 70%, and low elasticity, which is insufficient for the end use. In the document "Assembly of emulsion droplets inter fibers by microfluidic wet spinning. journal of Materials Chemistry A2016, 4(3),813 818", a porous fiber is disclosed, i.e. a fiber consisting of emulsion droplets is produced by synthesizing a pH-responsive polymer as a stabilizer for water-in-oil emulsion, and after the prepared emulsion droplets are contacted with acidic water, the electrostatic repulsion is lost due to protonation, and the fibers are locked and produced through the interaction of van der Waals force and hydrogen bonds when colliding with each other, the aggregation process is reversible, and the fibers are decomposed into single droplets under alkaline conditions, so that the fibers have no mechanical properties.

In order to meet the actual requirement, the oil-in-water emulsion is used as spinning solution to prepare the porous fiber with good mechanical property and stable chemical property, and the porous fiber is used for the rapid absorption of water, various organic solvents and heavy metal ions.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a porous fiber and a preparation method and application thereof, the fiber with a porous structure is prepared by adopting a wet spinning emulsion, the porous fiber has a high length-diameter ratio and a porous structure, and has a communicating pore structure inside, the mechanical property of the fiber is good, the breaking tensile strain can reach 120%, and the porous structure has adjustability, so that the absorption capacity of the fiber to liquid can be adjusted, the rapid absorption of water, various organic solvents and heavy metal ions can be realized, and the rapid exchange of substances and/or energy is facilitated.

A first object of the present invention is to provide a method for preparing porous fiber, comprising the steps of:

(1) adding an oil phase into a water phase, and uniformly mixing to obtain an oil-in-water emulsion, wherein the oil phase is an organic solution of a multi-thiol compound, and the multi-thiol compound is a small molecular compound containing 2-8 thiol groups; the water phase comprises a water-soluble emulsifier, a water-soluble polymer and water, and a molecular chain of the water-soluble polymer comprises 2-4 acrylate groups or acrylamide groups; the volume ratio of the oil phase to the water phase is 1: 1-6: 1;

(2) and extruding the oil-in-water emulsion serving as spinning stock solution into a coagulating bath for wet spinning, wherein the multi-sulfhydryl compound and the water-soluble polymer in the spinning stock solution are subjected to interfacial polymerization reaction, and the porous fiber is obtained after the reaction is completed.

Further, in the step (1), the multi-sulfhydryl compound accounts for 1-15% of the total volume of the oil phase; the multi-mercapto compound is pentaerythritol tetra-3-mercaptopropionate and/or trimethylolpropane tri (3-mercaptopropionate).

Further, in the step (1), the solvent in the oil phase is dichloromethane, cyclohexane, n-hexane, toluene, ethyl acetate, or the like.

Further, in the step (1), the water-soluble emulsifier accounts for 2-15% of the total weight of the water phase; the water-soluble emulsifier is poloxamer and/or alkylphenol polyoxyethylene. Preferably, the water soluble emulsifier is Pluronic F-127.

Further, in the step (1), the water-soluble polymer accounts for 3-30% of the total weight of the water phase; the water-soluble polymer is PEGDA (polyethylene glycol diacrylate), polyethylene glycol diacrylate, polyethylene glycol-polypropylene glycol-polyethylene glycol diacrylate or polyethylene glycol-polypropylene glycol-polyethylene glycol diacrylate.

Further, the molecular weight of the water-soluble polymer was 400-700 g/mol. Preferably, the water-soluble polymer has a molecular weight of 700 g/mol; the water-soluble polymer with the molecular weight of 700g/mol is adopted, so that the interfacial polymerization reaction speed is in a reasonable range, the porous morphology of the formed fiber is uniform, and the mechanical property is good. When the molecular weight of the water-soluble polymer is less than 400g/mol, smooth progress of the interfacial polymerization reaction cannot be ensured, and porous fibers cannot be formed.

Further, the molar ratio of sulfydryl in the multi-sulfydryl compound in the step (1) to carbon-carbon double bonds in the water-soluble polymer is 1: 0.9-0.9: 1.

Further, in the step (2), a coagulation bath used for wet spinning is an ammonia water solution, and the concentration of the ammonia water in the coagulation bath is 1-15 wt%.

Further, in the step (2), the temperature of the coagulation bath for wet spinning is 0-30 ℃.

Further, in the step (2), the spinning speed in the wet spinning process is 30-300 mL/h.

Further, in the step (2), in the wet spinning process, the diameter of the spinning needle head is 0.3-2.0 mm.

The invention uses water-soluble emulsifier, water-soluble polymer containing acrylate group or acrylamide group and water to form water phase, uses organic solution of multi-sulfhydryl compound as oil phase, after mixing uniformly, the oil phase is dispersed in the water phase, forms emulsion with certain viscosity and good spinnability as spinning dope; extruding the spinning solution into coagulating bath, dispersing the oil phase and water phase of the emulsion in the coagulating bath, catalyzing the oil phase monomer and water phase monomer of the emulsion to polymerize at the interface with catalyst (such as ammonia water) in the coagulating bath, solidifying the microstructure of the emulsion, and separating out fiber in the coagulating bath to form primary strand; the dispersed phase of the emulsion (i.e., the solvent in the aqueous and oil phases) is removed at a later stage, thereby forming voids or even hollow structures, and thus forming porous fibers. The presence of interconnected pores can be caused by solute concentration gradients between the aqueous phase and the coagulation bath and by the vulnerability of the interface between the continuous and dispersed phases.

The second purpose of the invention is to disclose a porous fiber prepared by the preparation method, wherein the diameter of the porous fiber is 100-500 μm; the fiber is internally provided with communicating pores, the average pore diameter is 5-400 mu m, and the average pore diameter of the communicating pores is 1-50 mu m; the density is 0.1 to 0.5g/cm³。

Furthermore, the porous fiber prepared by the method has good elasticity, and the breaking tensile strain of the porous fiber is 50-120%, which is superior to the elasticity of the existing porous fiber prepared by wet spinning.

The third purpose of the invention is to disclose the application of the porous fiber in preparing an adsorbent and/or absorbent of one or more of water, organic solvent, organic dye and heavy metal ions.

Further, the organic dye is methylene blue, congo red, rhodamine B and the like.

Further, the heavy metal ions are copper ions, iron ions, lead ions, and the like.

By the scheme, the invention at least has the following advantages:

the porous fiber is obtained by a method of wet spinning by utilizing reactive emulsion. The wet spinning emulsion has the advantages of high speed, continuous production and the like, so that the rapid and continuous production of the fiber can be realized.

The high length-diameter ratio of the fiber enables the porous fiber to realize rapid absorption of substances and energy; the porous fiber has a communicated pore structure, which is beneficial to the rapid exchange of substances and/or energy; the porous structure has adjustability, so that the liquid absorption amount of the porous structure can be adjusted, and a large amount of absorption can be realized.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following description is made with reference to the preferred embodiments of the present invention and the accompanying detailed drawings.

Drawings

FIG. 1 is a scanning electron micrograph of a cross section of a porous fiber according to examples 1, 2 and 3 of the present invention;

FIG. 2 is a thermogravimetric plot of porous fibers in examples 1, 2 and 3 of the present invention;

FIG. 3 is the tensile test results for the porous fibers of examples 1, 2 and 3 of the present invention;

FIG. 4 is a result of a water and various organic solvents absorption test of the porous fiber in examples 1, 2 and 3 of the present invention;

FIG. 5 is a representation of a porous fiber made according to the present invention.

Detailed Description

The following examples are given to further illustrate the embodiments of the present invention. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the following examples of the present invention, PEGDA is selected as the water-soluble polymer, and when the molecular weight thereof is less than 400g/mol, the interfacial polymerization reaction cannot be smoothly performed, and porous fibers cannot be formed. When the molecular weight of the PEGDA is 700g/mol, the porous morphology of the formed fiber is relatively uniform, and the mechanical property is good, so that in the following embodiments, the PEGDA is 700 g/mol.