Modified polyester fiber, preparation method thereof and textile

Abstract

The invention relates to a modified polyester fiber, a preparation method thereof and a textile. The preparation method of the modified polyester fiber comprises the following steps: S1, mixing terephthalic acid, isophthalic acid and ethylene glycol to obtain an esterification raw material, pulping the esterification raw material, mixing with an esterification catalyst, and carrying out esterification reaction in a protective gas atmosphere; s2, separating an organic phase from a water phase of an esterification reaction product, adding tris (trimethylsilyl oxidized) silanol, polyethylene glycol, a transesterification catalyst and a stabilizer into the organic phase, performing transesterification reaction in a protective gas atmosphere, casting a strip, and dicing; and S3, carrying out melt spinning on the prepared polyester chips. In the polycondensation process, tri (trimethylsilyl oxidized) silanol containing a silicon-oxygen group easy to hydrolyze is added, and the silicon-oxygen group is embedded into a molecular chain, so that the polyester fiber is easy to hydrolyze, the strength of the fiber is reduced, and the anti-pilling effect is improved; by adding m-phthalic acid, the structural regularity of a molecular chain can be destroyed, an amorphous region is expanded, and dye permeation is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of textiles, and particularly relates to a modified polyester fiber, a preparation method thereof, and a textile. Background Art

[0002] Polyester fiber, commonly known as "polyester", is a synthetic fiber made from polyester (where the chain links in the polymer macromolecular chain are connected by ester groups) formed by chemical polycondensation of organic dibasic acids and diols. Polyester fiber has the advantages of high strength, high modulus, good wrinkle resistance, good resilience, good dimensional stability, excellent abrasion resistance, non-fuzzing, heat resistance, light resistance, acid resistance, alkali resistance, solvent resistance, microorganism resistance, easy washing and quick drying, easy processing, and the fabric is crisp and not easy to deform. It can be spun pure or blended or interwoven with various natural fibers, and is widely used in the textile field such as carpets and indoor decorations.

[0003] However, polyester fiber has a linear polyester structure. This structure has a relatively large structural density, a small molecular spacing, a high degree of crystallinity, and a tight arrangement. It is difficult for dye molecules to penetrate into the fiber interior, resulting in poor dyeing effects. Secondly, polyester fiber has poor hydrophilicity and a high surface tension, making it difficult for water molecules to penetrate into the fiber interior, which affects the dyeing effect. Moreover, polyester fiber lacks active groups that can interact with dye molecules, leading to poor dyeing effects, low dye uptake rates, and being difficult to dye. In addition, the air permeability of polyester fiber is not good, and the user experience is not good. In related technologies, a high-temperature and high-pressure dyeing process is used to dye the greige cloth made of polyester fiber. Using this method for dyeing has a high energy consumption. In addition, the anti-pilling performance of polyester fiber needs to be further improved. Summary of the Invention

[0004] In view of this, the present invention provides a modified polyester fiber, a preparation method thereof, and a textile to solve the above technical problems such as poor dyeing effects and high energy consumption, and to improve the anti-pilling performance of polyester fiber.

[0005] To achieve the above solution, the technical solution of the present invention is as follows:

[0006] In the first aspect, the present application provides a preparation method of a modified polyester fiber, comprising the following steps:

[0007] S1. Mix terephthalic acid, isophthalic acid, and ethylene glycol to obtain an esterification raw material. After pulping the esterification raw material, mix it with an esterification catalyst, and carry out an esterification reaction in a protective gas atmosphere;

[0008] S2. Separate the organic phase and the aqueous phase of the esterification reaction product, add tris(trimethylsilyloxy)silanol, polyethylene glycol, a transesterification catalyst, and a stabilizer to the organic phase, and carry out a transesterification reaction, casting, and pelletizing in a protective gas atmosphere to obtain polyester chips;

[0009] S3. Melt-spin the polyester chips to obtain the modified polyester fibers.

[0010] In the polycondensation process of this application, tris(trimethylsilyloxy)silane containing hydrolyzable siloxane groups is added, which can directly embed the siloxane groups into the macromolecular chain of the polyester through polycondensation reaction, making the polyester fibers easy to hydrolyze in the subsequent processing, thereby reducing the fiber strength and improving the anti-pilling effect of the fibers. By adding isophthalic acid during the polyester synthesis, the structural regularity of the polyester macromolecular chain can be disrupted, expanding the amorphous region, which is beneficial to the penetration of dyes. By adding isophthalic acid during the polyester synthesis, hydroxyl groups that are easy to combine with dyes can be introduced into the polyester molecular chain, reducing the dyeing temperature and pressure, and reducing energy consumption and environmental pollution. By adding polyethylene glycol during the polyester synthesis, the flexibility of the polyester molecular chain can be improved, the glass transition temperature of the polyester can be reduced, and the dyeing temperature can be reduced.

[0011] Optionally, in step S1, the molar ratio of terephthalic acid, isophthalic acid to ethylene glycol is 1:0.1 - 0.2:1.3 - 1.5, preferably 1:0.15 - 0.2:1.35 - 1.5.

[0012] Optionally, in step S1, the speed of beating is 30 - 50 r / min, preferably 35 - 50 r / min; the duration of beating is 30 - 75 min, preferably 35 - 75 min.

[0013] Optionally, in step S1, the esterification catalyst is selected from 4-dimethylaminopyridine, p-toluenesulfonic acid or a combination of the two.

[0014] Optionally, in step S1, the mass ratio of the esterification catalyst to the esterification raw materials is 1 - 3:100, preferably 1.2 - 3:100.

[0015] Optionally, in step S1, the temperature of the esterification reaction is 200 - 220 °C, preferably 205 - 220 °C; the pressure of the esterification reaction is 0.3 - 0.5 MPa, preferably 0.35 - 0.5 MPa.

[0016] Optionally, in step S1, the esterification raw materials further include pentaerythritol.

[0017] Optionally, in step S1, the molar ratio of pentaerythritol to terephthalic acid is 0.03 - 0.06:1, preferably 0.04 - 0.06:1.

[0018] In this application, by adding the modified monomer pentaerythritol during the polyester synthesis process, pentaerythritol can be introduced into the polyester polymer chain through copolymerization reaction, resulting in branched chains in the polyester polymer chain. Utilizing the branching effect, the anti-wear length and anti-bending degree of the fiber are reduced, and the anti-pilling tendency is decreased to further enhance the anti-pilling effect.

[0019] Optionally, in step S2, the transesterification catalyst is selected from at least one of antimony acetate, antimony glycolate, and antimony trioxide.

[0020] Optionally, in step S2, the molar ratio of the transesterification catalyst to the terephthalic acid is 0.05 - 0.15:100, preferably 0.08 - 0.15:100.

[0021] Optionally, in step S2, the molar ratio of tris(trimethylsilyloxy) silanol to the terephthalic acid is 0.2 - 0.4:1, preferably 0.25 - 0.4:1.

[0022] Optionally, in step S2, the molar ratio of polyethylene glycol to the terephthalic acid is 0.1 - 0.2:1, preferably 0.15 - 0.2:1.

[0023] Optionally, in step S2, the stabilizer is selected from at least one of triethyl phosphate, trimethyl phosphate, and triphenyl phosphate.

[0024] Optionally, in step S2, the molar ratio of the stabilizer to the terephthalic acid is 0.01 - 0.03:100.

[0025] Optionally, in step S2, the temperature of the transesterification reaction is 180 - 200 °C.

[0026] Optionally, in step S3, the temperature of the melt spinning is 170 - 190 °C.

[0027] In this application, by adjusting the temperature of the melt spinning, the spinnability and the stability of the spinning process can be ensured.

[0028] In the second aspect, this application also provides a modified polyester fiber prepared by the method as described above.

[0029] In the third aspect, this application also provides a textile, which is made of the modified polyester fiber prepared by the method as described above.

[0030] In this application, the textile includes but is not limited to: dark-colored fabrics, such as dark-colored fabrics suitable for wedding and other series. When making the above-mentioned modified polyester fiber into a textile, the dyeing temperature rising curve can be adjusted so that different dyes can fully exert the dyeing performance of the above-mentioned polyester fiber. Detailed implementation manners

[0031] The present invention will be further described below through specific specific examples. It should be noted that the specific material ratios, process conditions, results, etc. described in the embodiments of the present invention are only used to illustrate the present invention and cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

[0032] An embodiment of the present application provides a method for preparing a modified polyester fiber, including the following steps:

[0033] S1. Mix terephthalic acid, isophthalic acid and ethylene glycol in a molar ratio of 1:0.1 - 0.2:1.3 - 1.5 to obtain an esterification raw material;

[0034] Pulverize the esterification raw material, and the pulverizing speed is 30 - 50 r / min, and the pulverizing duration is 30 - 75 min;

[0035] Mix the pulverized esterification raw material with an esterification catalyst. The mass ratio of the esterification catalyst to the esterification raw material is 1 - 3:100. The esterification catalyst is selected from 4 - dimethylaminopyridine, p - toluenesulfonic acid or a combination of the two. Carry out an esterification reaction in a protective gas atmosphere. The temperature of the esterification reaction is 200 - 220 °C, and the pressure of the esterification reaction is 0.3 - 0.5 MPa;

[0036] S2. Separate the organic phase and the aqueous phase of the esterification reaction product, and add tris(trimethylsilyloxy)silanol, polyethylene glycol, a transesterification catalyst and a stabilizer to the organic phase to obtain a reactant. The molar ratio of the transesterification catalyst to terephthalic acid is 0.05 - 0.15:100. The transesterification catalyst is selected from at least one of antimony acetate, antimony glycolate and antimony trioxide. The molar ratio of tris(trimethylsilyloxy)silanol to terephthalic acid is 0.2 - 0.4:1. The molar ratio of polyethylene glycol to terephthalic acid is 0.1 - 0.2:1. The molar ratio of the stabilizer to terephthalic acid is 0.01 - 0.03:100. The stabilizer is selected from at least one of triethyl phosphate, trimethyl phosphate and triphenyl phosphate;

[0037] Carry out a transesterification reaction, casting and pelletizing in a protective gas atmosphere to obtain polyester chips. The temperature of the transesterification reaction is 180 - 200 °C;

[0038] S3. Melt - spin the polyester chips at a temperature of 170 - 190 °C to obtain modified polyester fibers.

[0039] In another embodiment, in step S1, the esterification raw material further includes pentaerythritol, and the molar ratio of pentaerythritol to terephthalic acid is 0.03 - 0.06:1.

[0040] Another embodiment of the present application also provides a modified polyester fiber prepared by the method as described above.

[0041] Another embodiment of the present application also provides a textile, which is made of the modified polyester fiber prepared by the method as described above.

[0042] The present invention will be described in detail below by way of specific exemplary embodiments. It should be understood that the following embodiments are only used to specifically illustrate the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the protection scope of the present invention. The specific process parameters and the like in the following examples are also only an example within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description herein, rather than being limited to the specific values in the following examples.

[0043] Example 1

[0044] A method for preparing a modified polyester fiber, the specific steps are as follows:

[0045] S1. Mix terephthalic acid, isophthalic acid and ethylene glycol in a molar ratio of 1:0.1:1.5 to obtain an esterification raw material;

[0046] Pulverize the esterification raw material, the pulverizing speed is 30 r / min, and the pulverizing duration is 75 min;

[0047] Mix the pulverized esterification raw material with p-toluenesulfonic acid, the mass ratio of p-toluenesulfonic acid to the esterification raw material is 3:100, and carry out an esterification reaction in nitrogen, the temperature of the esterification reaction is 200 °C, and the pressure of the esterification reaction is 0.5 MPa;

[0048] S2. Separate the organic phase and the aqueous phase of the esterification reaction product, add tris(trimethylsilyloxy)silanol, polyethylene glycol, antimony acetate and trimethyl phosphate to the organic phase to obtain a reactant, the molar ratio of antimony acetate to terephthalic acid is 0.05:100, the molar ratio of tris(trimethylsilyloxy)silanol to terephthalic acid is 0.2:1, the molar ratio of polyethylene glycol to terephthalic acid is 0.2:1, and the molar ratio of trimethyl phosphate to terephthalic acid is 0.01:100;

[0049] Carry out a transesterification reaction, casting and pelletizing in nitrogen to obtain polyester chips, and the temperature of the transesterification reaction is 200 °C;

[0050] S3. Melt-spin the polyester chips at a temperature of 170 °C to obtain the modified polyester fiber.

[0051] Example 2

[0052] A preparation method of modified polyester fiber is as follows:

[0053] S1. Mix terephthalic acid, isophthalic acid and ethylene glycol according to a molar ratio of 1:0.2:1.3 to obtain an esterification raw material;

[0054] Slurry the esterification raw material at a speed of 50 r / min for 30 min;

[0055] Mix the slurried esterification raw material with 4-dimethylaminopyridine. The mass ratio of 4-dimethylaminopyridine to the esterification raw material is 1:100. Conduct an esterification reaction in nitrogen. The temperature of the esterification reaction is 220 °C, and the pressure of the esterification reaction is 0.3 MPa;

[0056] S2. Separate the organic phase and the aqueous phase of the esterification reaction product. Add tris(trimethylsilyloxy)silanol, polyethylene glycol, antimony glycolate and triphenyl phosphate to the organic phase to obtain a reactant. The molar ratio of antimony glycolate to terephthalic acid is 0.15:100. The molar ratio of tris(trimethylsilyloxy)silanol to terephthalic acid is 0.4:1. The molar ratio of polyethylene glycol to terephthalic acid is 0.1:1. The molar ratio of triphenyl phosphate to terephthalic acid is 0.03:100;

[0057] Conduct a transesterification reaction, casting and pelletizing in nitrogen to obtain polyester chips. The temperature of the transesterification reaction is 180 °C;

[0058] S3. Melt-spin the polyester chips at 190 °C to obtain modified polyester fiber.

[0059] Example 3

[0060] A preparation method of modified polyester fiber is as follows:

[0061] S1. Mix terephthalic acid, isophthalic acid and ethylene glycol according to a molar ratio of 1:0.15:1.4 to obtain an esterification raw material;

[0062] Slurry the esterification raw material at a speed of 40 r / min for 55 min;

[0063] Mix the slurried esterification raw material with p-toluenesulfonic acid. The mass ratio of p-toluenesulfonic acid to the esterification raw material is 2:100. Conduct an esterification reaction in nitrogen. The temperature of the esterification reaction is 210 °C, and the pressure of the esterification reaction is 0.4 MPa;

[0064] S2. Separate the esterification reaction product into an organic phase and an aqueous phase. Add tris(trimethylsilyloxy)silanol, polyethylene glycol, antimony trioxide, and triethyl phosphate to the organic phase to obtain a reactant. The molar ratio of antimony trioxide to terephthalic acid is 0.10:100, the molar ratio of tris(trimethylsilyloxy)silanol to terephthalic acid is 0.3:1, the molar ratio of polyethylene glycol to terephthalic acid is 0.15:1, and the molar ratio of triethyl phosphate to terephthalic acid is 0.02:100;

[0065] Conduct a transesterification reaction, pelletize the ribbon, and cut into pellets in nitrogen to obtain polyester chips. The temperature of the transesterification reaction is 190 °C;

[0066] Melt-spin the polyester chips at a temperature of 180 °C to obtain modified polyester fibers.

[0067] Example 4

[0068] Prepare modified polyester fibers in the same manner as in Example 1, except for the following conditions:

[0069] S1. Mix terephthalic acid, isophthalic acid, ethylene glycol, and pentaerythritol in a molar ratio of 1:0.1:1.5:0.06 to obtain an esterification raw material;

[0070] Slurry the esterification raw material at a speed of 30 r / min for 75 min;

[0071] Mix the slurried esterification raw material with p-toluenesulfonic acid. The mass ratio of p-toluenesulfonic acid to the esterification raw material is 3:100. Conduct an esterification reaction in nitrogen. The temperature of the esterification reaction is 200 °C, and the pressure of the esterification reaction is 0.5 MPa.

[0072] That is, the difference between this example and Example 1 is that the esterification raw material further includes pentaerythritol, and the molar ratio of pentaerythritol to terephthalic acid is 0.06:1.

[0073] Example 5

[0074] Prepare modified polyester fibers in the same manner as in Example 1, except for the following conditions:

[0075] S1. Mix terephthalic acid, isophthalic acid, ethylene glycol, and pentaerythritol in a molar ratio of 1:0.1:1.5:0.03 to obtain an esterification raw material;

[0076] Slurry the esterification raw material at a speed of 30 r / min for 75 min;

[0077] Mix the esterified raw material after beating with p-toluenesulfonic acid. The mass ratio of p-toluenesulfonic acid to the esterified raw material is 3:100. Conduct the esterification reaction in nitrogen. The temperature of the esterification reaction is 200 °C, and the pressure of the esterification reaction is 0.5 MPa.

[0078] That is, the difference between this example and Example 1 is that: the esterified raw material further includes pentaerythritol, and the molar ratio of pentaerythritol to terephthalic acid is 0.03:1.

[0079] Comparative Example 1

[0080] Prepare the modified polyester fiber in the same manner as in Example 1 except for the following conditions:

[0081] S2. Separate the organic phase and the aqueous phase of the esterification reaction product, and add polyethylene glycol, antimony acetate and trimethyl phosphate to the organic phase to obtain a reactant. The molar ratio of antimony acetate to terephthalic acid is 0.05:100, the molar ratio of polyethylene glycol to terephthalic acid is 0.2:1, and the molar ratio of trimethyl phosphate to terephthalic acid is 0.01:100;

[0082] Conduct the transesterification reaction, casting and pelletizing in nitrogen to obtain polyester chips. The temperature of the transesterification reaction is 200 °C.

[0083] That is, the difference between this comparative example and Example 1 is that: tris(trimethylsilyloxy)silane is not added in step S2.

[0084] Comparative Example 2

[0085] Prepare the modified polyester fiber in the same manner as in Example 1 except for the following conditions:

[0086] S1. Mix terephthalic acid and ethylene glycol in a molar ratio of 1:1.5 to obtain an esterified raw material;

[0087] Beat the esterified raw material. The beating speed is 30 r / min, and the beating duration is 75 min;

[0088] Mix the esterified raw material after beating with p-toluenesulfonic acid. The mass ratio of p-toluenesulfonic acid to the esterified raw material is 3:100. Conduct the esterification reaction in nitrogen. The temperature of the esterification reaction is 200 °C, and the pressure of the esterification reaction is 0.5 MPa.

[0089] That is, the difference between this comparative example and Example 1 is that: isophthalic acid is not added in step S1.

[0090] Comparative Example 3

[0091] Prepare the polyester fiber in the same manner as in Example 1 except for the following conditions:

[0092] S2. Separate the esterification reaction product into an organic phase and an aqueous phase, add tris(trimethylsilyloxy)silanol antimony acetate and trimethyl phosphate to the organic phase to obtain a reactant, the molar ratio of antimony acetate to terephthalic acid is 0.05:100, the molar ratio of tris(trimethylsilyloxy)silanol to terephthalic acid is 0.2:1, and the molar ratio of trimethyl phosphate to terephthalic acid is 0.01:100;

[0093] Conduct a transesterification reaction, casting, and pelletizing in nitrogen to obtain polyester chips, and the temperature of the transesterification reaction is 200 °C.

[0094] That is, the difference between this comparative example and Example 1 is that: polyethylene glycol was not added in step S2.

[0095] Testing

[0096] Make the modified polyester fibers prepared in Examples 1-5 and Comparative Example 1 into fabrics respectively, and test the pilling grade of each fabric according to "GB / T 4802.4-2020 Textiles - Determination of the pilling property of fabrics - Part 4: Random tumbling method" (the higher the pilling grade, the better the pilling resistance performance), and the results are shown in Table 1.

[0097] Table 1 Test results of pilling resistance performance

[0098] Group Pilling level Example 1 3.5 Example 2 3.5 Example 3 3.0 Example 4 4.5 Example 5 4.5 Comparative Example 1 2

[0099] As can be seen from Table 1, compared with Comparative Example 1, the pilling grade of Example 1 increased significantly. This result shows that in the polycondensation process of this application, adding tris(trimethylsilyloxy)silanol containing easily hydrolyzable siloxane groups can directly embed the siloxane groups into the macromolecular chain of polyester through polycondensation reaction, making the polyester fiber easy to hydrolyze in the subsequent processing process, thereby reducing the strength of the fiber and improving the pilling resistance effect of the fiber.

[0100] As can be seen from Table 1, compared with Example 1, the pilling grades of Example 4 and Example 5 increased significantly. This result shows that in this application, by adding the modified monomer pentaerythritol in the polyester synthesis process, pentaerythritol can be introduced into the polyester macromolecular chain through copolymerization reaction, resulting in branched chains in the polyester macromolecular chain. Utilizing the branching effect, the anti-wear length and anti-bending degree of the fiber are reduced, and the pilling tendency is reduced to further improve the pilling resistance effect.

[0101] Make the modified polyester fibers prepared in Examples 1-3 and Comparative Examples 2-3 into fabrics respectively, measure the K / S value of the fabrics at λmax using a computer color measurement and matching instrument (the higher the K / S value, the deeper the color depth), and the results are shown in Table 2, and test the wash fastness of each fabric according to "GB / T5713-2013 Textiles - Tests for colour fastness - Colour fastness to washing" (the higher the grade, the better the colour fastness), and the results are shown in Table 2.

[0102] Table 2 Test Results of Dyeing Performance

[0103]

[0104] As can be seen from Table 2, compared with Comparative Example 2, the K / S value and wash fastness of Example 1 are both significantly improved. That is, the color depth of the fabric in Example 1 is deeper than that in Comparative Example 2, and the color fastness of the fabric in Example 1 is better than that in Comparative Example 2. This result shows that by adding isophthalic acid during the polyester synthesis process in this application, the structural regularity of the polyester macromolecular chain can be disrupted, the amorphous region can be expanded, which is beneficial to the penetration of dyes. By adding isophthalic acid during the polyester synthesis process, hydroxyl groups that are easy to combine with dyes can be introduced into the polyester molecular chain, reducing the dyeing temperature and pressure, and thus improving the dyeing effect.

[0105] As can be seen from Table 2, compared with Comparative Example 3, the K / S value and wash fastness of Example 1 are both significantly improved. That is, the color depth of the fabric in Example 1 is deeper than that in Comparative Example 3, and the color fastness of the fabric in Example 1 is better than that in Comparative Example 3. This result shows that by adding polyethylene glycol during the polyester synthesis process in this application, the flexibility of the polyester molecular chain can be increased, the glass transition temperature of the polyester can be reduced, and the dyeing temperature can be lowered, thus improving the dyeing effect.

[0106] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a modified polyester fiber, characterized in that: The following steps are involved: S1. Mix terephthalic acid, isophthalic acid and ethylene glycol to obtain an esterification raw material, slurry the esterification raw material and mix it with an esterification catalyst, and carry out an esterification reaction in a protective gas atmosphere; S2. The esterification reaction product is separated into an organic phase and an aqueous phase, tris(trimethylsilyl oxide)silanol, polyethylene glycol, an ester exchange catalyst and a stabilizer are added to the organic phase, and an ester exchange reaction is carried out in a protective gas atmosphere, a strip is cast, and a pellet is cut to obtain a polyester chip; S3. The polyester chips are melt-spun to obtain the modified polyester fibers.

2. The method for preparing modified polyester fiber according to claim 1, characterized in that: In step S1, the molar ratio of the terephthalic acid, the isophthalic acid and the ethylene glycol is 1:0.1-0.2:1.3-1.5; And / or, in step S1, the beating speed is 30-50 r / min, and the beating time is 30-75 min.

3. The method for preparing modified polyester fiber according to claim 1, characterized in that: In step S1, the esterification catalyst is selected from 4-dimethylaminopyridine, p-toluenesulfonic acid or a combination thereof; And / or, in step S1, the mass ratio of the esterification catalyst to the esterification raw material is 1-3:100; And / or, in step S1, the temperature of the esterification reaction is 200-220° C., and the pressure of the esterification reaction is 0.3-0.5 MPa.

4. The method for preparing modified polyester fiber according to claim 1, characterized in that: In step S1, the esterification raw material also includes pentaerythritol.

5. The method for preparing modified polyester fiber according to claim 4, characterized in that: In step S1, the molar ratio of the pentaerythritol to the terephthalic acid is 0.03-0.06:

1.

6. The method for preparing modified polyester fiber according to claim 1, characterized in that: In step S2, the transesterification catalyst is selected from at least one of antimony acetate, antimony glycol and antimony trioxide; and / or, in step S2, the molar ratio of the transesterification catalyst to the terephthalic acid is 0.05-0.15:100; and / or, in step S2, the molar ratio of the tris(trimethylsilyl oxide)silanol to the terephthalic acid is 0.2-0.4:1; And / or, in step S2, the molar ratio of the polyethylene glycol to the terephthalic acid is 0.1-0.2:

1.

7. The method for preparing modified polyester fiber according to claim 1, characterized in that: In step S2, the stabilizer is selected from at least one of triethyl phosphate, trimethyl phosphate and triphenyl phosphate; And / or, in step S2, the molar ratio of the stabilizer to the terephthalic acid is 0.01-0.03:

100.

8. The method for preparing modified polyester fiber according to claim 1, characterized in that: In step S2, the temperature of the transesterification reaction is 180-200°C; And / or, in step S3, the temperature of the melt spinning is 170-190°C.

9. A modified polyester fiber prepared according to the method according to any one of claims 1 to 8.

10. A textile, characterized in that: The textile product is made of modified polyester fiber prepared according to the method according to any one of claims 1 to 8.

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