阅读说明：本技术 一种亲水共聚物、亲水纤维、亲水薄膜，及其制备方法 (Hydrophilic copolymer, hydrophilic fiber, hydrophilic film and preparation method thereof ) 是由 何春菊 曲智华 曲智清 于 2018-06-19 设计创作，主要内容包括：本发明涉及一种亲水共聚物,是将亲水单体接枝到骨架聚合物上得到的共聚物,骨架聚合物选自于纤维素、甲壳素、壳聚糖中的一种或一种以上的组合,亲水共聚物包含亲水链段0.5wt％～40wt％,该亲水共聚物对水的吸附量为4g/g以上,或对于血液的吸附量为2g/g以上,或对于尿液的吸附量为2g/g以上。本发明还涉及上述亲水共聚物的制备方法,以及使用上述亲水共聚物制得的纤维、薄膜,以及该纤维、薄膜的制备方法。(The invention relates to a hydrophilic copolymer, which is obtained by grafting a hydrophilic monomer onto a skeleton polymer, wherein the skeleton polymer is selected from one or more of cellulose, chitin and chitosan, the hydrophilic copolymer comprises 0.5-40 wt% of hydrophilic chain segments, and the adsorption capacity of the hydrophilic copolymer to water is more than 4g/g, or the adsorption capacity to blood is more than 2g/g, or the adsorption capacity to urine is more than 2 g/g. The invention also relates to a preparation method of the hydrophilic copolymer, fibers and films prepared from the hydrophilic copolymer, and a preparation method of the fibers and films.)

1. A hydrophilic copolymer is obtained by grafting a hydrophilic monomer onto a skeleton polymer, wherein the skeleton polymer is selected from one or more of cellulose, chitin and chitosan, the hydrophilic copolymer comprises 0.5-40 wt% of hydrophilic chain segments, and the adsorption capacity of the hydrophilic copolymer to water is more than 4 g/g.

2. The hydrophilic copolymer of claim 1, wherein the hydrophilic copolymer comprises 0.5 wt% to 30 wt% of the hydrophilic segment.

3. The hydrophilic copolymer according to claim 1 or 2, wherein the hydrophilic monomer is at least one selected from the group consisting of (meth) acrylic acid, sodium (meth) acrylate, (meth) acrylamide, (meth) acrylate, and N-vinylpyrrolidone.

4. The hydrophilic copolymer according to claim 1 or 2, wherein the graft polymerization is carried out by dissolving the backbone polymer in a solvent and further adding an initiator and the hydrophilic monomer.

5. A hydrophilic fiber comprising the hydrophilic copolymer as set forth in any one of claims 1 to 4.

6. The hydrophilic fiber of claim 5, wherein the hydrophilic fiber has a strength of 2.2cN/dtex or more.

7. The hydrophilic fiber according to claim 5, wherein the amount of adsorption to urine is 2g/g or more and/or the amount of adsorption to blood is 2g/g or more.

8. A hydrophilic film comprising the hydrophilic copolymer according to any one of claims 1 to 4.

9. The hydrophilic film according to claim 8, wherein the strength of the hydrophilic film is 5.0MPa or more.

10. The hydrophilic film according to claim 8, wherein the amount of adsorption to urine is 2g/g or more and/or the amount of adsorption to blood is 2g/g or more.

11. A method for preparing a hydrophilic copolymer, comprising the steps of:

1) dissolving a skeleton polymer in a solvent to form a solution, wherein the skeleton polymer is selected from one or more of cellulose, chitin and chitosan;

2) adding an initiator and a hydrophilic monomer into the solution obtained in the step 1) for graft polymerization;

the hydrophilic copolymer comprises 0.5-40 wt% of hydrophilic chain segments, and the adsorption capacity of the hydrophilic copolymer to water is 4 g/g.

12. The method of claim 11, wherein the hydrophilic copolymer comprises 0.5 wt% to 30 wt% of the hydrophilic segment.

13. The method according to claim 11, wherein the hydrophilic monomer is at least one selected from the group consisting of (meth) acrylic acid, sodium (meth) acrylate, (meth) acrylamide, (meth) acrylate, and N-vinylpyrrolidone.

14. The method according to claim 11, wherein the graft polymerization is carried out at a temperature of 40 to 150 ℃ for 1 to 72 hours under the protection of an inert gas.

15. The preparation method according to any one of claims 11 to 14, wherein the step 1) further comprises the steps of alkalizing, squeezing, crushing and yellowing the skeleton polymer, so as to dissolve the skeleton polymer to obtain a viscose solution with a total solid content of 3 to 30 wt%.

16. The method according to any one of claims 11 to 14, wherein in step 1), the solvent is selected from a binary system formed by mixing a mono-system of an ionic liquid, a mono-system of N-methylmorpholine N-oxide, lithium chloride and paraformaldehyde with one selected from dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, hexamethylphosphoramide and tetramethylurea respectively, so as to dissolve the two components to obtain a solution with a total solid content of 3 to 30 wt%.

17. The method of claim 16, wherein an acid scavenger, a nucleophile, a complexing agent and a catalyst are added in step 2) to initiate the graft polymerization.

18. The method of claim 17, wherein the acid scavenger is at least one selected from triethylamine, sodium hydroxide, potassium hydroxide, and pyridine.

19. The method of claim 17, wherein the nucleophile is selected from at least one of bromoacyl bromide or bromoacyl chloride.

20. The method of claim 17, wherein the complexing agent is selected from at least one of bipyridine, PMDETA, Me6TREM, TPMA, or p-cymene.

21. The method of claim 17, wherein the catalyst is cuprous halide.

22. The method according to any one of claims 11 to 14, wherein in step 1), the solvent is at least one selected from the group consisting of organic acids, inorganic acids, and acidic ionic liquids, and forms a solution having a total solid content of 1 to 10 wt%.

23. A method for preparing a hydrophilic fiber using the hydrophilic copolymer prepared by the process of claim 11.

24. A method for preparing a hydrophilic film using the hydrophilic copolymer prepared by the process of claim 11.

Technical Field

The present invention relates to a hydrophilic copolymer and a preparation method thereof, and a hydrophilic fiber or a hydrophilic film made of the copolymer and a preparation method thereof.

Background

The cellulose, chitin and chitosan in nature have large reserves and huge recovery amount. At present, only a few cellulose, chitin and chitosan are made into fibers. The fiber or film made of the raw materials of cellulose, chitin and chitosan can be biologically decomposed or safely burnt into water vapor and carbon dioxide, and the waste of the fiber or film has little harm to the environment. In addition, the product has the characteristics of wide raw material source, degradability, good mechanical property, moisture absorption, air permeability, static resistance, gorgeous dyeing and the like, and is widely applied to the fields of textile, medical treatment and the like.

Hydrophilic fibers or films made from cellulose, chitin, chitosan as raw materials are basic components of absorbent products, e.g. diapers, and these fibers or films form the main functional element in liquid-absorbent structures, i.e. absorbent products. Therefore, how to effectively increase the unit liquid absorption amount and liquid acquisition capacity of the cellulose fibers and the film is very important. The absorption capacity and liquid acquisition capacity of the present fibers and films need to be further improved due to the partially crystalline structure of the fibers and films during the forming process.

Most of the hydrophilic fibers and films reported at present are made by crosslinking cellulose fibers and films, see U.S. Pat. nos. US5137537A and US5190563A, but the fibers and films obtained by the above methods have relatively short shelf lives and are limited in some applications. In addition, the bacteriostatic activity of the absorbent product is very important, and at present, methods such as adding nano silver and antibacterial drugs are mostly adopted to achieve the purpose, but the problems of easy dissolution of bacteriostatic substances, potential safety risks, great influence on the environment and the like exist.

Disclosure of Invention

To overcome the above-mentioned drawbacks of the hydrophilic regenerated cellulose articles of the prior art, the present invention provides hydrophilic copolymers by initiating grafting of hydrophilic monomers in different solvent systems. The grafting modification is one of matrix modification, has the characteristics of simple operation, good effect, economy, practicality and the like, grafts the hydrophilic polymer on a macromolecule, avoids the defect of hydrophilic copolymerization loss, and the hydrophilic chain segment can be enriched on the surfaces of fibers and films due to the induction action in the fiber-forming phase separation process, so that the hydrophilicity of the fibers and the films is unexpectedly and remarkably improved.

The hydrophilic monomer is connected to the skeleton polymer through graft polymerization by the process, the skeleton polymer is selected from at least one of cellulose, chitin and chitosan, and the prepared fiber and film materials have excellent capacity of absorbing and keeping liquid; and because the chitin and the chitosan have natural antibacterial activity, the chitosan can also be widely applied to the field of medical treatment and health.

The invention aims to provide a hydrophilic copolymer, which is obtained by grafting a hydrophilic monomer onto a skeleton polymer, wherein the skeleton polymer is selected from one or more of cellulose, chitin and chitosan, the prepared hydrophilic copolymer comprises 0.5-40 wt% of hydrophilic chain segments, and the adsorption capacity of the hydrophilic copolymer to water is more than 4 g/g.

In the present invention, the skeleton polymer is selected from one or a combination of more than one of cellulose, chitin and chitosan, and in fact, a polysaccharide substance, that is, a polysaccharide substance represented by the general formula (C)₆H₁₀O₅)_nThe materials of the present invention can be used as the skeleton polymer. In the present invention, the hydrophilic monomer is selected based on its solubility in the selected solvent and the water absorption properties required for the finished product.

Alternatively, the hydrophilic copolymer comprises 0.5 wt% to 30 wt% of the hydrophilic segment. If the content of the hydrophilic segment in the hydrophilic copolymer is less than 0.5 wt%, the hydrophilicity is insufficient, and the defect of poor liquid absorption and retention property cannot be overcome; if the mass percentage of the hydrophilic chain segment in the hydrophilic copolymer is more than 30%, the dissolution loss of the hydrophilic copolymer is increased when the hydrophilic copolymer is used for preparing fibers, membranes and other products in the subsequent process, the strength of the fibers and the membranes in a wet state is poor, and the production cost is too high.

Alternatively, the hydrophilic monomer is selected from at least one of (meth) acrylic acid, (meth) sodium acrylate, (meth) acrylamide, (meth) acrylate, N-vinyl pyrrolidone.

Further, the graft polymerization is carried out by dissolving the skeleton polymer in a solvent and then adding an initiator and a hydrophilic monomer. A large number of active groups such as hydroxyl, acetamido, amino and the like exist on cellulose, chitin and chitosan, and can activate an initiation point under the action of an initiator so as to initiate a hydrophilic monomer to be grafted on a skeleton polymer. Wherein, the initiator comprises: water-soluble azo-type initiators, for example: azobisisobutylamidine hydrochloride, azobisisobutylimidazoline hydrochloride, azobiscyanovaleric acid, azobisisopropylimidazoline, and the like; redox initiators, for example: hydrogen peroxide, metal salts of peroxides, persulfates, etc., as an oxidizing agent, ferrous salts, sodium bisulfite, etc., as a reducing agent; and an initiation system formed by adding an acid-binding agent, a nucleophilic reagent, a complexing agent and a catalyst into the solvent, which will be further explained in the following description.

The invention also provides a hydrophilic fiber which comprises the hydrophilic copolymer.

Further, the strength of the hydrophilic fiber is 2.2cN/dtex or more.

Further, the hydrophilic fiber has an adsorption amount of 2g/g or more to urine or an adsorption amount of 2g/g or more to blood.

The present invention also provides a hydrophilic film comprising the hydrophilic copolymer as described above.

Further, the strength of the hydrophilic film is 5.0MPa or more

Further, the hydrophilic film has an adsorption amount of 2g/g or more with respect to urine or an adsorption amount of 2g/g or more with respect to blood.

The invention has the beneficial effects that the fiber or the film containing the hydrophilic copolymer can have permanent hydrophilicity, and compared with the traditional surface coating and blending modification, the durability of the hydrophilicity is effectively improved. Meanwhile, chitin and chitosan have bacteriostatic activity, so that the bacteriostatic rate of fibers and films prepared from the chitin and the chitosan serving as raw materials on staphylococcus aureus, escherichia coli and candida albicans can reach more than 99.9%.

Another object of the present invention is to provide a method for preparing the above hydrophilic copolymer, comprising the steps of:

1) dissolving a skeleton polymer in a solvent to form a solution, wherein the skeleton polymer is selected from one or more of cellulose, chitin and chitosan;

2) adding an initiator and a hydrophilic monomer into the solution obtained in the step 1) for graft polymerization;

the hydrophilic copolymer comprises 0.5-40 wt% of hydrophilic chain segments, and the adsorption capacity of the hydrophilic copolymer to water is 4 g/g.

Alternatively, the hydrophilic copolymer comprises 0.5 wt% to 30 wt% of the hydrophilic segment.

Alternatively, the hydrophilic monomer is selected from at least one of (meth) acrylic acid, (meth) sodium acrylate, (meth) acrylamide, (meth) acrylate, N-vinyl pyrrolidone.

Further, the graft polymerization is carried out for 1-72 hours under the protection of inert gas and at the temperature of 40-150 ℃.

According to one aspect of the invention, the step 1) further comprises the steps of alkalizing, squeezing, crushing and yellowing the skeleton polymer, and finally dissolving to obtain the viscose solution with the total solid content of 3-30 wt%. Alkalization, which is the process of reacting chitin and/or cellulose with alkaline substances to generate alkali cellulose and/or alkali chitin. Yellowing refers to the combination of alkali cellulose and/or alkali chitin with carbon disulfide (CS)₂) Reacting to generate corresponding xanthate. In the embodiment, the framework polymer is preferably cellulose and/or chitin, the framework polymer is alkalized and yellowed to obtain a cellulose xanthate solution, active sites are formed under the action of an initiator, and a hydrophilic monomer is initiated to be grafted on the framework polymer through graft polymerization.

Specifically, firstly, soaking cellulose in 140-220 g/L alkali liquor for 45-300 minutes at 20-55 ℃, and squeezing to 2.5-5 times of dry weight. Alternatively, of lyeThe concentration is 170-200 g/L, the time is 60-200 minutes, the temperature is 38-50 ℃, and the squeezing multiple is 3-4 times. Mechanically pulverizing, aging at 10-40 deg.C for 8-30 hr or without aging, vacuumizing, and adding 20-90% (for raw material) CS₂Yellowing is carried out for 0.5-10 hours at the temperature of 5-70 ℃, and the yellowing bath ratio depends on the adopted method and raw materials. Alternatively, CS₂The addition amount is 30-70% of the mass of the cellulose. The yellowing temperature is 15-45 ℃, and the yellowing time is 1-3 hours. And adding a proper amount of alkali liquor and soft water for dissolving to obtain a stock solution with the cellulose content of 3-15%, preferably 7-10%.

Then, the chitin is dipped in alkali liquor with the concentration of 250-550g/L for 45-300 minutes, the dipping temperature is-30-10 ℃, and the chitin is squeezed to 2.5-5 times of the dry weight. Optionally, the dipping time is 60-200 minutes, and the pressing multiple is 3-4 times. After mechanical crushing, the mixture is not aged or is aged at 10-40 ℃ for 8-30 hours, optionally, the aging temperature is 15-35 ℃, and the aging time is 10-20 hours. Vacuumizing, and adding 20-90% (for raw material) CS₂Yellowing at 5-70 deg.c for 0.5-10 hr in certain bath ratio, and optionally CS₂The addition amount is 30-70% of the mass of the cellulose, the yellowing temperature is 15-45 ℃, and the yellowing time is 1-3 hours. And finally, adding a proper amount of alkali liquor and soft water for dissolving to obtain a stock solution with the chitin content of 3-15%, preferably 7-10%.

In the step 2) of the present embodiment, the molar ratio of the hydrophilic monomer, the cellulose and/or the chitin, and the initiator is 1000-10000: 1: 100-1000.

In the blended viscose solution, the mass ratio of the chitin to the cellulose is 1-19.

In the above embodiment, the skeleton polymer is chitin or a hydrophilic copolymer prepared by blending cellulose and chitin, the skeleton polymer contains chitin, and the prepared hydrophilic copolymer has a bacteriostasis rate of more than 99.9% on staphylococcus aureus, escherichia coli and candida albicans. FIG. 2a shows the proliferation of Staphylococcus aureus in 18 hours on the blank; FIG. 2b is the reproduction of Staphylococcus aureus in 18 hours on hydrophilic fibers made with cellulose and chitin blended as the backbone polymer; FIG. 3a is the propagation of E.coli on the blank within 18 hours; FIG. 3b is the reproduction of Escherichia coli in 18 hours on hydrophilic fiber made with cellulose and chitin as the skeleton polymer; FIG. 4a is the proliferation of Candida albicans on the blank within 18 hours; FIG. 4b shows the propagation of Candida albicans on hydrophilic fibers made with cellulose and chitin blended as the backbone polymer within 18 hours. The blank sample refers to a hydrophilic fiber prepared by using cellulose as a skeleton polymer and adopting the method.

According to a second aspect of the present invention, in step 1) of the present embodiment, cellulose and chitin are dissolved together in a solvent; or respectively dissolving cellulose and chitin in a solvent to obtain a non-derivative cellulose solution and a non-derivative chitin solution, wherein the mass percentage concentration of the cellulose and the chitin in the solution is 3-30 wt%, and then blending, wherein the dissolving temperature is 75-150 ℃. Wherein the solvent is selected from a unitary system of ionic liquid, a unitary system of N-methylmorpholine N-oxide, a binary system formed by mixing lithium chloride and paraformaldehyde with one selected from dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, hexamethylphosphoramide and tetramethylurea respectively. Wherein, the ionic liquid consists of cations and anions, the cations are alkyl quaternary ammonium ions, alkyl quaternary phosphonium ions, alkyl imidazolium ions or alkyl pyridinium ions, the substituents of which are one or more of hydrogen, C1-C6 alkyl, vinyl, propenyl, butenyl, hydroxyethyl, hydroxypropyl and alkoxy; the anion is halide, BF₄ ^-、PF₄ ^-、SCN^-、CN^-、OCN^-、CNO^-、CF₃SO₃ ^-、CF₃COO^-、(CF₃SO₂)₂N^-Or (CF)₃SO₂)₂Cl^-One kind of (1). Alternatively, the solvent is 1-butyl 3-methylimidazolium chloride, N-methylmorpholine N-oxide, chlorineA solvent system consisting of lithium chloride and dimethylacetamide or paraformaldehyde and dimethyl sulfoxide.

Further, in this embodiment, an acid scavenger, a nucleophile, a complexing agent, and a catalyst are added in step 2) to initiate the graft polymerization. Specifically, dissolving an acid-binding agent in cellulose, chitin or a cellulose/chitin blended solution, slowly dropwise adding a nucleophilic reagent, and reacting at-10-80 ℃ for 3-24 hours, preferably at-5-40 ℃ for 8, 15 and 20 hours, wherein the weight ratio of the acid-binding agent to the nucleophilic reagent is 3-12, preferably: 5.7 and 11. The mol ratio of the hydrophilic monomer, the cellulose and/or the chitin, the complexing agent and the catalyst is 1000-10000: 1: 100-1000: 10-500, and preferably 3000-7000: 1: 500-700: 50-250.

Optionally, the acid-binding agent is selected from at least one of triethylamine, sodium hydroxide, potassium hydroxide or pyridine.

Further, the nucleophilic reagent is selected from at least one of bromoacyl bromide or bromoacyl chloride, preferably 2-bromoisobutyryl bromide or 2-bromoisobutyryl chloride.

Optionally, the complexing agent is selected from at least one of bipyridine, Pentamethyldiethylenetriamine (PMDETA), tripropylene glycol methyl ether acetate (TPMA), tris- (N, N-dimethylaminoethyl) amine (Me6TREM), p-cymene.

Further, the catalyst is cuprous halide, specifically cuprous bromide or cuprous chloride.

According to another aspect of the invention, in the step 1), the solvent is selected from at least one of organic acid, inorganic acid and acidic ionic liquid, and a solution with a total solid content of 1-10 wt% is formed. Specifically, chitosan is dissolved in the above solvent as a backbone polymer. Among them, the solvent is preferably acidic ionic liquid prepared from formic acid, acetic acid, adipic acid, lactic acid, succinic acid, tartaric acid, nitric acid, hydrochloric acid, perchloric acid, phosphoric acid, metal halide and organic chloride, or solution of hydrochloride.

Furthermore, the mole ratio of the hydrophilic monomer, the chitosan and the initiator is 1000-10000: 1: 100-1000.

The invention also provides a preparation method of the hydrophilic fiber, which is prepared by using the hydrophilic copolymer prepared by the previous step. Fig. 1 is a schematic diagram of a hydrophilic fiber production line.

Specifically, a hydrophilic copolymer solution obtained by graft polymerization is defoamed in vacuum, pressed into a coagulating bath, and the spinning pressure and the spinning speed are adjusted; then the fiber is extruded by a spinning nozzle, solidified by a coagulating bath, stretched in multiple steps, and post-treated by various bath liquids to thoroughly remove various impurities in the fiber, and the hydrophilic fiber is obtained after water washing, oiling and drying. More specifically, the hydrophilic copolymer solution is subjected to vacuum defoaming for 1-48 hours, the obtained nascent fiber is subjected to a 0-200 mm dry spinning process and then enters a coagulating bath for coagulation and regeneration, the sulfuric acid content in the coagulating bath is 28-150 g/L, the sodium sulfate content is 40-350 g/L, the zinc sulfate content is 0.8-80 g/L, the bath temperature is 5-70 ℃, and the spinning speed is 50-100 m/min. The stretching is that the nascent fiber is subjected to nozzle (positive or negative) stretching, guide plate stretching, five-stage stretching, plasticizing stretching, stretching after air bath and proper retraction, and the total stretching ratio is 20-200%, preferably 40%, 70%, 110% and 150% by adopting a plurality of or all of the stretching combinations. Wherein the cross-sectional shape of the fiber is conventional or irregular. The water washing is to soak and wash the nascent fiber in soft water for 24-48 hours, and the oiling and drying time is 5-12 hours, preferably 7-10 hours.

Or, the hydrophilic copolymer solution is subjected to vacuum defoaming, spinning jet extrusion, coagulation bath coagulation, stretching and retraction to obtain nascent fiber, and the nascent fiber is subjected to extraction, soaking and cleaning, and finally oiling treatment to obtain the hydrophilic fiber. And (3) defoaming the hydrophilic copolymer solution for 5-48 hours in vacuum, and then, allowing the obtained nascent fiber to enter a coagulating bath for coagulation and regeneration after a dry spinning process of 0-300 mm, wherein the coagulating bath is a water bath or an extractant bath, and the bath temperature is 0-100 ℃. The stretching is carried out by one or a combination of a plurality of stretching methods including tension stretching, nozzle stretching, plasticizing stretching, stretching after air bath or retraction, and the like, wherein the total stretching rate is 3-400%. The cross-sectional shape of the fiber is conventional and irregular. The extractant is water or a mixture of alcohol and water, and a solvent and water. The alcohol is monohydric alcohol, polyhydric alcohol or a mixture thereof. The monohydric alcohol can be methanol, absolute ethyl alcohol and the like, and the polyhydric alcohol can be ethylene glycol and the like. The water washing is to soak and clean the nascent fiber in pure water for 6-24 hours, and the oiling and drying time is 5-12 hours. Through the steps, the strength of the hydrophilic fiber can be more than 2.2 cN/dtex.

The invention also provides a preparation method of the hydrophilic film, which is prepared by using the hydrophilic copolymer prepared by the previous step.

Specifically, the hydrophilic polymer solution obtained after graft polymerization is subjected to vacuum defoaming, flat-plate membrane scraping, coagulation by a coagulation bath, extraction, soaking and cleaning, and finally treatment with a pore-protecting agent for 5-12 hours to obtain the hydrophilic film, wherein the film strength of the hydrophilic film is more than 5.0 MPa. Specifically, the flat plate is a glass plate. The extractant is water or the mixture of alcohol and water, solvent and water. The alcohol is monohydric alcohol, polyhydric alcohol or a mixture thereof. The monohydric alcohol can be methanol, absolute ethyl alcohol and the like, and the polyhydric alcohol can be ethylene glycol and the like. The pore-protecting agent is alcohol or its water solution. The alcohol is preferably one or a mixture of more than two of methanol, ethanol, isopropanol, glycol and glycerol, and the time for hole protection treatment is preferably 7-10 hours. More specifically, the content of sulfuric acid in the coagulating bath is 28-150 g/L, the content of sodium sulfate is 40-350 g/L, the content of zinc sulfate is 0.8-80 g/L, and the bath temperature is 5-70 ℃. The soaking and cleaning is carried out in soft water for 10-48 hours. Or the coagulating bath is a water bath or an extractant bath, and the temperature of the coagulating bath is 0-50 ℃. The soaking and cleaning are carried out in pure water for 6-24 hours. Through the steps, the strength of the hydrophilic film can reach more than 5.0 MPa.

Optionally, the hydrophilic fibers or hydrophilic membranes are treated with an alkaline solution to further increase hydrophilicity.

The alkaline solution is at least one selected from an aqueous solution of lithium hydroxide, sodium hydroxide, potassium hydroxide, and calcium hydroxide, and a monohydric alcohol solution such as methanol and absolute ethanol.

Specifically, the hydrophilic fiber and the hydrophilic film are treated by an alkali solution with the mass percentage concentration of 1-20% for 5-120 minutes at the temperature of-10-50 ℃, and the mass ratio of the skeleton polymer to the alkali solution is 1: 2-1: 20. Preferably, monohydric alcohol or aqueous solution of 3-15% sodium hydroxide and potassium hydroxide of aqueous alkali is used for treating for 10-60 minutes at 0-40 ℃, and the mass ratio of the skeleton polymer to the aqueous alkali is 1: 3-1: 10.

The invention has the advantages of simple preparation process, unexpected improvement of the hydrophilicity of the hydrophilic fiber and the hydrophilic film prepared from the hydrophilic polymer, long preservation time and bacteriostasis.

Drawings

FIG. 1 is a schematic view of a hydrophilic fiber production line;

FIG. 2a is a graph of the proliferation of Staphylococcus aureus on a blank over 18 hours;

FIG. 2b is the reproduction of Staphylococcus aureus in 18 hours on hydrophilic fibers made with cellulose and chitin blended as the backbone polymer;

FIG. 3a is the propagation of E.coli on the blank within 18 hours;

FIG. 3b is the reproduction of Escherichia coli in 18 hours on hydrophilic fiber made with cellulose and chitin as the skeleton polymer;

FIG. 4a is the proliferation of Candida albicans on the blank within 18 hours;

FIG. 4b shows the propagation of Candida albicans on hydrophilic fibers made with cellulose and chitin blended as the backbone polymer within 18 hours.

Description of the component numbering

1 metering pump

2 spinning jet

3 coagulating bath

4 first drafting device

5 second drafting device

6 winding device

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure. While the invention will be described in connection with the preferred embodiments, there is no intent to limit its features to those embodiments. On the contrary, the invention is described in connection with the embodiments for the purpose of covering alternatives or modifications that may be extended based on the claims of the present invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The invention may be practiced without these particulars. Moreover, some of the specific details have been left out of the description in order to avoid obscuring or obscuring the focus of the present invention.

Cellulose, chitin and chitosan are difficult to dissolve in conventional solvents due to strong intramolecular and intermolecular hydrogen bonds. And the macromolecule is only uniformly dispersed and dissolved in the solvent, namely when the macromolecule is dispersed in the solvent in a molecular state, the hydrophilic monomer molecule and the skeleton polymer are fully contacted and reacted, thereby ensuring the grafting efficiency. In an embodiment of the present invention, three solvent systems are further provided to enable the backbone polymer to be dispersed in a solvent, although the scope of the present invention is not limited in this respect.

Firstly, a test method and a standard:

the test evaluation method of the technical indexes of the hydrophilic fiber and the hydrophilic film obtained in the embodiments of the invention comprises the following steps:

cross-sectional and surface micro-morphology: breaking the dry film in liquid nitrogen or directly sputtering platinum, and testing by using a Japanese JSM-5600LV type scanning electron microscope;

liquid absorption rate: and putting the product into a clean beaker, adding 250ml of liquid, soaking for 24 hours, filtering out redundant liquid by using a 200-mesh screen, and weighing the mass of the filtered liquid by using a balance. The water absorption multiplying power calculation formula is as follows:

Q＝(M₂-M₁)/M₁

in the formula: q represents the liquid-absorbing magnification (unit: g.g)^-1)，M₁Represents the mass of the resin (unit: g) before immersion, M₂: represents the mass of the resin (unit: g) after filtering off the liquid.

Ultimate tensile strength, elongation at break: the dry/wet film and the fiber are cut into strips with certain sizes and then tested by a new vinpocetine brand WDW3020 microcomputer controlled electronic universal tester.

And (3) measuring the content of the hydrophilic polymer: and carrying out quantitative and qualitative analysis on the hydrophilic fiber and the hydrophilic film by using an EDX (electron-ray diffraction) energy spectrum equipped by a scanning electron microscope.

II, experimental materials:

1. bamboo pulp (alpha-cellulose content 94%, degree of polymerization 450): southern paper limited, Fujian province;

2. cotton pulp (α -cellulose content 98%, polymerization degree 720): shandong high density silver eagle chemical fiber, Inc.;

3. wood pulp (α -cellulose content 96%, polymerization degree 1200): russian black needle brand;

4. bacterial cellulose (alpha-cellulose content 99%, degree of polymerization 2500): hainan Guangyu technologies, Inc.;

5. cotton (α -cellulose content 99%, degree of polymerization 980): shanxi Zhongbao Cotton company;

6. reed pulp: (α -cellulose content 92%, polymerization degree 520): shandong high density silver eagle chemical fiber, Inc.;

7. shrimp chitin

8. Crab shell extract

9. Cray chitin

10. Chitin maggot

11. Squid cartilage chitin

12. And (3) chitosan: shrimp chitosan, crab chitosan, crawfish chitosan, maggot chitosan, squid cartilage chitosan

Cellulose: 19-1% of chitin

Other reagents were purchased from Shanghai chemical company, China medicine (group).

(meth) acrylic acid, (meth) sodium acrylate, an acrylamide-based monomer, a methacrylamide-based monomer, an acrylate-based monomer, a methacrylate-based monomer, N-vinylpyrrolidone, and the like.

Preferred initiators are azobisisobutylamidine hydrochloride, azobisisobutylimidazoline hydrochloride, hydrogen peroxide/ferrous chloride, sodium persulfate/ferrous chloride, potassium persulfate/sodium bisulfite.