TWI521107B - Preparing method of polysaccharide fiber - Google Patents

Description

Method for preparing polysaccharide fiber

The present invention relates to a method for preparing a polysaccharide fiber, and more particularly to a method for preparing a regenerated polysaccharide fiber.

In recent years, scientists have actively developed the production of recycled fibers to replace the consumption of natural fibers by dissolving existing polymer materials. Recycled fibers can be used in a wide variety of industries, such as home textiles, optical films, flexible electronic displays, cosmetics, medical drugs and food additives. In the process of reclaiming fibers, various chemical or physical methods are generally used to make the regenerated fibers have various functions to meet the market demand, such as gas permeability, moisture absorption, easy dyeing, antistatic, antibacterial and the like.

In the textile industry, the treatment of waste cotton fabrics is the focus of research. Since cellulose fibers have both flexibility and hygroscopicity, they are quite suitable as raw materials for nonwoven fabrics. At present, cellulose non-fibrous cloth is a solvent using cellulose as N-methylmorpholine N-oxide (NMMO). However, the use of NMMO to dissolve cellulose requires not only high temperatures, but also a complicated forming process to increase its Preparation costs. Therefore, there is a need for a process for preparing recycled fibers which is simple in process and can be carried out at room temperature.

The invention provides a preparation method of polysaccharide fiber, which has the advantages of simple process.

The present invention provides a method for preparing a polysaccharide fiber, which comprises the following steps. First, a polysaccharide material is provided. Next, the polysaccharide material is mixed with the ionic liquid to form a polysaccharide solution. Then, the polysaccharide solution is mixed with the molding liquid to form a polysaccharide shaped product. Next, the polysaccharide shaped product is homogenized to form a polysaccharide homogenate. The polysaccharide homogenate is then dried to form a polysaccharide fiber.

In an embodiment of the present invention, in the method for producing a polysaccharide fiber, a polysaccharide material and an ionic liquid are mixed at room temperature to form a polysaccharide solution.

In an embodiment of the present invention, in the method for preparing the polysaccharide fiber, the homogenization treatment is performed by using a high-speed stirring homogenizer to form a polysaccharide homogenate, and the polysaccharide homogenate is dried to form a large amount. The saccharide fiber is in a non-woven fabric.

In an embodiment of the present invention, in the method for preparing a polysaccharide fiber, the homogenization treatment step is performed by using an emulsifier homogenizer to form a polysaccharide homogenate, and the polysaccharide homogenate is dried. The saccharide fiber is in a film form.

In an embodiment of the invention, in the method for preparing the polysaccharide fiber, the polysaccharide material comprises a cellulose-containing material, a chitin-containing material or a starch-containing material.

In an embodiment of the present invention, the method for preparing the above polysaccharide fiber Among the cellulose-containing materials include wood pulp, bamboo, hemp, rice straw, coconut shell, sugar cane or cotton.

In an embodiment of the invention, in the method for preparing the polysaccharide fiber, the chitin-containing material comprises a shrimp shell, a crab shell, an insect shell or a squid cartilage.

In an embodiment of the invention, in the method for preparing the polysaccharide fiber, the starch-containing material comprises seeds, tubers or roots of the plant.

In an embodiment of the invention, in the method for producing a polysaccharide fiber, the ionic liquid is composed of a cation and an anion. The cation includes the structure represented by the formula (1):

Wherein R ₁ to R ₅ are H or a hydrocarbon group having 1 to 8 carbon atoms; and the anion is one selected from the group consisting of Cl ^- , Br ^- , I ^- , CH ₃ COO ^- and HCOO ^- and PO ₄ ^3- .

In an embodiment of the present invention, in the method for preparing the polysaccharide fiber, the ionic liquid comprises 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc). .

In an embodiment of the invention, in the method for producing a polysaccharide fiber, the molding liquid includes a first solvent and a second solvent. The first solvent includes water, methanol, ethanol, acetone, or a combination thereof. The second solvent includes an ionic liquid, dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc) or Its combination.

In an embodiment of the present invention, in the method for producing a polysaccharide fiber, the non-woven fabric type polysaccharide fiber has an average fiber diameter of from 13 μm to 30 μm.

In an embodiment of the present invention, in the method for producing a polysaccharide fiber, the film-type polysaccharide fiber has an average fiber diameter of from 0.080 μm to 0.200 μm.

In an embodiment of the invention, in the method for preparing the polysaccharide fiber, mixing the polysaccharide material with the ionic liquid further comprises heating to 60 ° C to 80 ° C.

In an embodiment of the present invention, in the method for producing the polysaccharide fiber, the homogenization treatment is 3 to 5 minutes.

In an embodiment of the present invention, in the method for preparing a polysaccharide fiber, the polysaccharide material further comprises a reactive dye, and after the polysaccharide solution is mixed with the molding liquid, the reactive dye is separated from the polysaccharide material. To form a polysaccharide shaped article that does not have a reactive dye.

Based on the above, in the method for producing a polysaccharide fiber proposed in the examples of the present invention, an ionic liquid which is liquid at room temperature is used. Therefore, the polysaccharide material can be mixed with the ionic liquid at room temperature to improve the convenience of the process. Further, the polysaccharide molded article may be subjected to different homogenization treatments as needed to obtain a polysaccharide fiber of a non-woven fabric type or a film type. Further, in the method for producing a polysaccharide fiber according to the embodiment of the present invention, the reactive dye may be separated from the polysaccharide material, and the decolorized regenerated polysaccharide fiber may be obtained without subjecting to centrifugation.

In order to make the above features and advantages of the present invention more apparent, the following is a special The embodiments are described in detail below in conjunction with the drawings.

S100~S500‧‧‧Steps

1 is a flow chart showing a method of preparing a polysaccharide fiber according to an embodiment of the present invention.

1 is a flow chart showing a method of preparing a polysaccharide fiber according to an embodiment of the present invention. Referring to Fig. 1, first, step S100 is performed to provide a polysaccharide material. In the present embodiment, the polysaccharide material is, for example, a cellulose-containing material, a chitin-containing material or a starch-containing material. In the natural world, the content of cellulose ranks first. The cellulose-containing material is, for example, wood pulp, bamboo, hemp, rice straw, coconut shell, sugar cane or cotton. The chitin-containing material is, for example, a shrimp shell, a crab shell, an insect shell or a squid cartilage. Chitin is the second largest natural polymer material second only to cellulose, and chitin has good biocompatibility, hygroscopicity, and superior antibacterial and deodorant functions. The starch-containing material is, for example, a seed, tuber or root of a plant, but the invention is not limited thereto.

In the present embodiment, the above polysaccharide material may be finely ground using physical strength, such as pulverization or grinding, but the invention is not limited thereto. Generally, a polysaccharide material generally has a plurality of hydrogen bond donors and a hydrogen bond acceptor in its molecular structure. For example, in the polysaccharide material of the present embodiment, the hydrogen bond provider is a hydrogen atom in the hydroxyl group, and the hydrogen bond acceptor is an oxygen atom in the hydroxyl group. As a result, polysaccharide materials are not only molecules Hydrogen bonds are widely present inside, and have a certain degree of intramolecular polarity. Hydrogen bonds are easily generated between molecules and molecules of polysaccharide materials, which will make polysaccharide materials in conventional solvents (such as water and most organic solvents, etc.). It is difficult to dissolve.

In the present embodiment, referring to step S200 of FIG. 1, the above polysaccharide material is mixed with an ionic liquid to form a polysaccharide solution. In detail, the cation and anion in the ionic liquid can interact with the oxygen atom and the hydrogen atom in the polysaccharide material, thereby breaking the hydrogen bond between the molecules of the polysaccharide material, thereby fully dissolving the polysaccharide material, and A polysaccharide solution is formed. In the present embodiment, the above polysaccharide solution is a clear solution, but the invention is not limited thereto.

In this embodiment, the ionic liquid consists of a cation and an anion. The cation may include the structure represented by the formula (1):

In the present embodiment, R ₁ to R ₅ may be H or a hydrocarbon group having 1 to 8 carbon atoms. In this embodiment, the anion may be selected from one of Cl ^- , Br ^- , I ^- , CH ₃ COO ^- and HCOO ^- and PO ₄ ^3- .

In one embodiment, the ionic liquid is, for example, 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc), and its structure is represented by the following formula (2).

In particular, an ionic liquid having an anion of CH ₃ COO ⁻ (1-ethyl-3-methylimidazolium acetate as described above) and an anion having an anion of an ionic liquid of another species (for example, Cl ⁻ ) are The ionic liquid of CH ₃ COO ^- can dissolve the same amount of polysaccharide material at a lower temperature, thereby reducing the energy used in dissolution.

It is worth mentioning that the above ionic liquid is still liquid at room temperature. Therefore, the above polysaccharide material can be mixed with the ionic liquid directly at room temperature. However, in other embodiments, the dissolution rate of the polysaccharide material may also be accelerated by means of heating in step S200. The heating temperature is, for example, 60 ° C to 80 ° C, but the invention is not limited thereto.

Referring to step S300 of Fig. 1, the above polysaccharide solution is mixed with a molding liquid to form a polysaccharide shaped product. In the present embodiment, the molding liquid may include a first solvent and a second solvent. The first solvent is, for example, water, methanol, ethanol, acetone or a combination thereof. The second solvent is, for example, any of the above ionic liquids, dimethyl hydrazine (DMSO), dimethyl acetamide (DMAc), or a combination thereof, but the invention is not limited thereto.

It is worth mentioning that the first embodiment of the polysaccharide formed after step S300 is filled with a first solvent (for example, water) and a second solvent (for example, an ionic liquid). Therefore, after the step S300, the polysaccharide shaped product is gel-like and there is not enough time to form crystals, so that the force between the molecules is weak.

Next, referring to step S400 of Fig. 1, the polysaccharide molded product is homogenized to form a polysaccharide homogenate. Since the polysaccharide shaped product has not yet formed crystals, the polysaccharide shaped body can be easily homogenized by physical force such as stirring or ultrasonic vibration. The time of homogenization treatment is, for example, 3 to 5 minutes, The invention is not limited to this. Then, referring to step S500 of Fig. 1, the above polysaccharide homogenate is dried to form a polysaccharide fiber. In the present embodiment, the drying method is, for example, that the polysaccharide homogenate is suction-filtered and then left to stand for 24 hours, but the present invention is not limited thereto.

It is worth mentioning that in this embodiment, different homogeneous processing modes can be selected as needed. For example, the above polysaccharide shaped article can be treated using a high speed agitation homogenizer to form a polysaccharide homogenate. Next, after drying the polysaccharide homogenate, a polysaccharide fiber of a non-woven fabric type can be formed. The non-woven fabric type polysaccharide fiber may have an average fiber diameter of from 13 μm to 30 μm. In one embodiment, the above polysaccharide fibers have an average fiber diameter of 15 μm, but the invention is not limited thereto. Alternatively, the polysaccharide shaped article may be treated with an emulsification homogenizer to form a polysaccharide homogenate. Next, the polysaccharide homogenate is dried and pressed to form a translucent film-type polysaccharide fiber. The film type polyester fiber may have an average fiber diameter of from 0.080 μm to 0.200 μm.

After all the above steps S100 to S500 are carried out, the preparation of the polysaccharide fiber of the present embodiment can be completed.

It is worth mentioning that in an embodiment, the polysaccharide material may further comprise a reactive dye. The reactive dye is composed of a dye precursor and a linking group which forms a chemical bond with a plurality of functional groups of the polysaccharide material. The dye precursor of the reactive dye used in the polysaccharide material is, for example, azo, hydrazine, phthalocyanine or the like. The linking group of the above reactive dye is, for example, a s-triazine, a vinyl hydrazine, a quinoxaline, a pyrimidine or the like. In the method for preparing a polysaccharide fiber according to an embodiment of the present invention, reactivity is included After the dye solution of the dye is mixed with the molding liquid, the reactive dye can be separated from the polysaccharide material, and the reactive dye can be introduced into the first solvent to form a decolored polyester shaped article.

Hereinafter, the preparation of the polysaccharide fibers proposed in the above examples and their characteristics will be described in detail by way of several experimental examples. However, the following experimental examples are not intended to limit the invention.

[Preparation of polysaccharide fiber]

In order to prove that the preparation method of the polysaccharide fiber of the present invention can prepare a polysaccharide fiber and the process is simple, the following examples are particularly made.

Example 1

First, the wood pulp or cotton fabric is pulverized. Next, 5 to 10% by weight of the cellulose slime is prepared at 60 ° C to 80 ° C using [EMIM]OAc as a solvent. Then, 20 g of the cellulose slime was poured out or squeezed into 1 liter of water to form a cellulose formed product. Next, the cellulose molded product was homogenized by a high-speed stirring homogenizer at a number of revolutions of 10,000 rpm to 26,000 rpm for 3 to 5 minutes to form a cellulose homogenate. Finally, the cellulose homogenate was suction filtered, and then left to stand for 24 hours to obtain a cellulose non-woven fabric. This cellulose nonwoven fabric had an average fiber diameter of 15 μm.

Example 2

First, 1 gram of black and white newspaper was cut into a size of 2 cm x 2 cm, and it was immersed in a 1% aqueous sodium hydroxide solution for 1 hour to remove the ink. Then, after 20 g of [EMIM]OAc was dissolved at 80 ° C for 4 hours, cellulose adhesion was obtained. liquid. Subsequently, the cellulose slime was poured into a high-speed stirring homogenizer, and homogenized for 5 minutes at a rotational speed of 10,000 rpm to 26,000 rpm. Finally, it was collected by suction filtration and dried for 24 hours to obtain a cellulose non-woven fabric. This cellulose non-woven fabric had an average fiber diameter of 20 μm.

Example 3

First, 1 gram of chitin powder was prepared. Next, after 20 g of [EMIM]OAc was dissolved at 80 ° C for 8 hours, a chitin mucilage was obtained. Subsequently, the chitin mucilage was poured into a high-speed stirring homogenizer, and homogenization was carried out for 5 minutes at a rotation speed of 10,000 rpm to 26,000 rpm. Finally, it was collected by suction filtration and dried for 24 hours to obtain a chitin non-woven fabric. This chitin nonwoven fabric had an average fiber diameter of 30 μm.

[aggregation measurement]

NMMO and [EMIM]OAc were used to dissolve wood pulp board and cotton dyed fiber fabric containing 5% by weight of cellulose, respectively. The dissolution temperature was 80 ° C; the dissolution time was 8 hours. The degree of polymerization was calculated according to the following formula: degree of polymerization = (total molecular weight) / (molecular weight of 1 unit) * 100%. In addition, based on the degree of polymerization of the wood pulp board and the pure cotton dyed fiber fabric before dissolution, the retention rate of the dissolved wood pulp board and the pure cotton dyed fiber fabric is calculated, that is, the wood pulp before dissolution is calculated. The retention rate of the pulp board and the cotton dyed fiber fabric is regarded as 100%, and the retention ratio is calculated according to the following formula: retention ratio = (degree of polymerization of the polysaccharide material before dissolution) / (polysaccharide material after dissolution) polymerization Degree) *100%. The results are shown in Table 1 below.

It should be noted that the greater the degree of polymerization after dissolution of the polysaccharide material, the more the polysaccharide material retains its structure in the solvent, that is, the greater the retention. From the results of Table 1, it can be seen that under the same dissolution temperature and dissolution time, with [EMIM]OAc as the solvent, the degree of cellulose destruction is smaller than that of NMMO. Specifically, the retention rate of the former can be maintained by the latter. The rate is more than twice. Therefore, in the process of industrially using NMMO to dissolve cellulose, an additional protective agent is generally added to prevent cellulose degradation. In the method for producing a polysaccharide fiber of the present invention, an ionic liquid is used to treat cellulose, and the degree of degradation of cellulose can be greatly reduced as compared with the degree of degradation of cellulose using NMMO, so that no additional protective agent is required.

[Water absorption ratio measurement]

In the following, some experimental examples were specifically made to compare the water absorption ratios of the cellulose non-woven fabric obtained by the preparation method of the polysaccharide fiber of the present invention and a commercially available nonwoven fabric. The detailed steps of the water absorption rate measurement are as follows. First, weigh the weight T (gram) of the empty tea bag, and use the empty tea bag after weighing as a tool for holding the sample. Next, the weight S (gram) of the sample shown in Table 2 is weighed, and the weighed sample is placed in a tea bag. Subsequently, the above-mentioned tea bag containing the sample was immersed in distilled water for 5 minutes, and suspended for 5 minutes. After the excess water has been dripped, weigh the total weight W (g) of the tea bag and the sample after absorbing water. The water absorption ratio was calculated according to the following formula: water absorption ratio = (W - (T + S) - T * W ₀ ) / S, where W ₀ (gram) is the water absorption amount of 1 gram of tea bag. The calculation results are listed in Table 2.

Comparative Example 1 is a commercially available polypropylene (PP) nonwoven fabric, and Comparative Example 2 is a wood pulp cellulose nonwoven fabric obtained by using NMMO as a solvent. Experimental Example 1 was prepared using [EMIM]OAc as a solvent. Wood pulp cellulose was not woven, and Experimental Example 2 was a cotton cellulose non-woven fabric obtained by using [EMIM]OAc as a solvent. As is apparent from the results of Table 2, the water absorption ratio of the recycled fiber nonwoven fabric made using [EMIM]OAc is superior to that of the currently commercially available PP nonwoven fabric (about more than twice). Further, the water absorption ratio of the regenerated fiber nonwoven fabric made using [EMIM]OAc is comparable to the cellulose non-woven fabric currently using NMMO as a solvent.

It is worth mentioning that, by visual observation, in the above Experimental Example 2, the cotton fiber dyed with the reactive dye (azo and s-triazine) dissolved in [EMIM]OAc can help the cotton fiber to be decolored, and thus the white color can be obtained. Regenerated Cellulose Fiber. Conversely, cotton fibers dyed with reactive dyes were dissolved in NMMO to give pink regenerated cellulose fibers.

In summary, the preparation of the polysaccharide fiber proposed in the examples of the present invention In the method, an ionic liquid which is liquid at room temperature is used. Therefore, the polysaccharide material can be mixed with the ionic liquid at room temperature to improve the convenience of the process. Further, by using the above ionic liquid as a solvent, the structure of the polysaccharide material can be maintained at a good retention rate. If necessary, the polysaccharide shaped product may be subjected to different homogenization treatment to obtain a regenerated polysaccharide fiber of a non-woven fabric type or a film type, and the non-woven fabric type regenerated polysaccharide fiber may have a commercially available PP non-woven fabric. Excellent water absorption ratio. Further, in the method for producing a polysaccharide fiber according to the embodiment of the present invention, the reactive dye may be separated from the polysaccharide material, and the decolorized regenerated polysaccharide fiber may be obtained without subjecting to centrifugation.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

S100~S500‧‧‧Steps

Claims (16)

A method for preparing a polysaccharide fiber, comprising: providing a polysaccharide material; mixing the polysaccharide material with an ionic liquid to form a polysaccharide solution; mixing the polysaccharide solution with a forming liquid to form a polysaccharide a polysaccharide shaped product; the polysaccharide shaped body is subjected to a homogenization treatment to form a polysaccharide homogenate; and the polysaccharide homogenate is dried to form the polysaccharide fiber. The method for producing a polysaccharide fiber according to claim 1, wherein the polysaccharide material is mixed with the ionic liquid at room temperature to form the polysaccharide solution. The method for preparing a polysaccharide fiber according to claim 1, wherein the homogenization treatment is performed by using a high-speed stirring homogenizer to form the polysaccharide homogenate, and the polysaccharide homogenate is dried. The polysaccharide fiber formed is in a non-woven fabric state. The method for preparing a polysaccharide fiber according to claim 1, wherein the homogenization treatment is performed by using an emulsifier homogenizer to form the polysaccharide homogenate, and the polysaccharide homogenate is dried. The polysaccharide fiber is in a film form. The method for producing a polysaccharide fiber according to claim 1, wherein the polysaccharide material comprises a cellulose-containing material, a chitin-containing material or a starch-containing material. a method for preparing a polysaccharide fiber according to claim 5, which The cellulose-containing material includes wood pulp, bamboo, hemp, rice straw, coconut shell, sugar cane or cotton. The method for preparing a polysaccharide fiber according to claim 5, wherein the chitin-containing material comprises a shrimp shell, a crab shell, an insect shell or a squid cartilage. The method for producing a polysaccharide fiber according to claim 5, wherein the starch-containing material comprises seeds, tubers or roots of the plant. The method for producing a polysaccharide fiber according to claim 1, wherein the ionic liquid is composed of a cation and an anion, and the cation comprises the structure represented by the formula (1): Wherein R ₁ to R ₅ are H or a hydrocarbon group having 1 to 8 carbon atoms; and the anion is one selected from the group consisting of Cl ^- , Br ^- , I ^- , CH ₃ COO ^- , HCOO ^- and PO ₄ ^3- . The method for preparing a polysaccharide fiber according to claim 9, wherein the ionic liquid comprises 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) . The method for preparing a polysaccharide fiber according to claim 1, wherein the molding liquid comprises a first solvent and a second solvent, and the first solvent comprises water, methanol, ethanol, acetone or a combination thereof, and the first The two solvents include the ionic liquid, two Dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc) or a combination thereof. The method for producing a polysaccharide fiber according to the second aspect of the invention, wherein the non-woven fabric type polysaccharide fiber has an average fiber diameter of from 13 μm to 30 μm. The method for producing a polysaccharide fiber according to claim 3, wherein the film type polysaccharide fiber has an average fiber diameter of from 0.080 μm to 0.200 μm. The method for producing a polysaccharide fiber according to claim 1, wherein the mixing of the polysaccharide material with the ionic liquid further comprises heating to 60 ° C to 80 ° C. The method for producing a polysaccharide fiber according to claim 1, wherein the homogenization treatment is 3 to 5 minutes. The method for preparing a polysaccharide fiber according to claim 1, wherein the polysaccharide material further comprises a reactive dye, and after the polysaccharide solution is mixed with the molding liquid, the reactive dye is more than the reactive dye. The saccharide material is separated to form the polysaccharide shaped article which does not have the reactive dye.