A hetero-cooperative degradable polyester fiber and a method for preparing the same

Abstract

The present application relates to a kind of heterotypic synergic degradation polyester fiber and its preparation method, heterotypic synergic degradation polyester fiber contains not less than 1wt% of polymer containing hydrophilic group, cross section is zigzag, the height of zigzag tooth is 0.2-0.4 times of the diameter of circumscribed circle of zigzag, the number of zigzag tooth is 5-20;Preparation method includes: (1) preparation of degradation promoting master batch consisting of polymer containing hydrophilic group and polyethylene terephthalate;(2) polyethylene terephthalate, nanometer titanium dioxide, silicone, degradation promoting master batch and degradation master batch are dry, mixed evenly into melt spinning machine hopper;(3) using the spinneret of zigzag spinneret plate, extruded by screw extruder, obtain heterotypic synergic degradation polyester fiber.The method of the present application is simple, and the degradation rate of the heterotypic synergic degradation polyester fiber prepared is higher, and it has important significance for the improvement of environmental pollution caused by polyester waste.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester fibers and relates to a special-shaped synergistically degradable polyester fiber and a preparation method thereof. Background Art

[0002] Polyester fiber is widely used as a textile raw material due to its high strength, good elasticity, excellent heat and chemical resistance, and good dimensional stability. This has alleviated the shortage of natural fibers to a certain extent and greatly promoted the development of the textile market. However, its waste is difficult to degrade in nature and can easily cause serious environmental pollution.

[0003] Although technologies are currently available to recycle polyester materials, the amount of recycled materials is limited, and the recycled materials will eventually flow into nature, which has an unavoidable impact on the environment. Therefore, developing biodegradable polyester fiber materials is one of the most promising ways to solve the problem of polyester pollution.

[0004] Currently, the main method for degrading chemically synthesized fibers is through the addition of biodegradable masterbatches. Under specific environmental conditions, such as microbial activity and humidity in the soil, biodegradable masterbatches enable the polymer material to be decomposed by microorganisms, ultimately converting it into harmless substances such as water and carbon dioxide. Furthermore, the biodegradable masterbatch can be regulated as needed to control the degradation rate and degree of the fiber to adapt to different usage environments and application requirements. For example, Chinese invention patent CN113913965A reports a degradable polyester fiber and a method for preparing it. The cross-sectional shape of degradable fibers prepared by existing public technologies is mostly circular. Due to their small specific surface area, degradable fibers with circular cross-sections have a small contact area with microorganisms, water, air, etc. in the environment during the degradation process, which is not conducive to the entry of degradable substances into the fiber. Furthermore, the content of the added degradable masterbatch is relatively high, approximately 25%-30%. Other publicly available technologies for producing biodegradable fibers with profiled cross-sections include Chinese invention patent CN101742932A, which discloses a biodegradable cigarette filter. The profiled fibers form multiple microcavities for storing adsorbents, and their biodegradability relies primarily on the addition of naturally degradable ingredients, such as starch, to the fibers. Another example is Chinese invention patent CN109722727A, which discloses biodegradable super-bright FDY fibers and their preparation method. The profiled cross-section imparts a "shimmering" appearance to the fibers, and their biodegradability is achieved by introducing a degradable third monomer through copolymerization. Currently, the degradation rate of biodegradable polyesters is relatively low under composting conditions, requiring at least 120 days for the degradation rate to reach 80%. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems existing in the prior art, realize the accelerated degradation of polyester fibers, and provide a special-shaped synergistically degradable polyester fiber and a preparation method thereof.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A special-shaped collaborative degradable polyester fiber contains not less than 1 wt% of a polymer containing hydrophilic groups, has a sawtooth cross section, a sawtooth tooth height of 0.2-0.4 times the diameter of the sawtooth circumscribed circle, and has 5-20 teeth.

[0008] The degradation efficiency of the heterotypic synergistically degradable polyester fiber of the present invention is high because:

[0009] (1) The heterogeneous synergistically degradable polyester fiber of the present invention contains a certain amount of polymer containing hydrophilic groups, which can improve the affinity of the polyester fiber itself with water. Since microorganisms, enzymes, etc. are all hydrophilic substances, the introduction of a large number of hydrophilic groups (sulfonic acid groups, hydroxyl groups, etc.) can improve the affinity of microorganisms, enzymes and polyester fibers, improve the accessibility of microorganisms and enzymes, promote their enrichment on the fiber surface, and enhance the effect;

[0010] (2) The cross-section of the heterogeneous synergistically degradable polyester fiber of the present invention is zigzag-shaped. The special structure of the zigzag-shaped cross-section fiber will result in a large number of stress concentration areas at the top and bottom of the fiber zigzag structure, and a large number of stress concentration micro-units are generated on the zigzag edges. During the specific composting degradation process, these stress concentration micro-units are more likely to form microcracks. As the degradation proceeds, the microcracks continue to expand, making it easier for microorganisms, enzymes, etc. to enter the fiber interior to exert their effects, providing more pathways for microorganisms and enzymes to degrade the fiber.

[0011] The tooth height of the serrated shape is 0.2-0.4 times the diameter of the circumscribed circle of the serrated shape. The tooth height of the serrated shape should not be too high, otherwise an effective stress concentration zone cannot be formed, nor should it be too low, otherwise the edges of the nascent fibers will adhere after the melt is extruded from the spinneret, and a good serrated structure cannot be formed. The number of teeth in the serrated shape is 5-20. The number of teeth in the serrated shape should not be too large, otherwise the edges of the nascent fibers will adhere after the melt is extruded from the spinneret, which will reduce the number of serrated teeth in the fiber, resulting in a reduction in stress concentration zones, which is not conducive to improving degradation efficiency. The tooth height should not be too small, otherwise fewer stress zones will be formed in the spun fibers, which will affect the degradation efficiency.

[0012] The serrated grooves can also guide water, which is beneficial for the attachment of water to the fiber surface and can greatly increase the affinity of microorganisms, enzymes, etc. to the polyester fiber surface.

[0013] As the preferred technical solution:

[0014] In the above-mentioned heterogeneous synergistically degradable polyester fiber, the content of the polymer containing hydrophilic groups is not higher than 3.5 wt %.

[0015] As described above, the polymer containing the hydrophilic group in the heterogeneous synergistic degradable polyester fiber is ethylene terephthalate-dimethyl isophthalate-5-sodium sulfonate copolymer, wherein the ethylene terephthalate-dimethyl isophthalate-5-sodium sulfonate copolymer contains hydrophilic sulfonic acid groups, which is beneficial to the accessibility of microorganisms and enzymes.

[0016] The above-mentioned special-shaped synergistically degradable polyester fiber further contains 1-3wt% of nano-titanium dioxide and 1-5wt% of organosilicon. The nano-titanium dioxide is added as an inorganic filler, and the organosilicon is used to improve the compatibility of the inorganic filler with the polymer matrix.

[0017] In the above-mentioned special-shaped collaboratively degradable polyester fiber, the organosilicon is diphenylsilanediol or methacryloxypropyltrimethoxysilane.

[0018] The above-mentioned heterotypic synergistically degradable polyester fiber has a specification of 20-300D / 8-96F, such as 20D / 8F, 25F / 8F, 30D / 8F, 40D / 12 / F, 50D / 12F, 60D / 18F, 70D / 24F, 100D / 36F, 120D / 36F, 150 / 48F, 210D / 72F, 250D / 72F, and 300D / 96F, and a fineness of 2.77-4.63 dtex. Under composting conditions, the 30-day degradation rate of the heterotypic synergistically degradable polyester fiber reaches more than 80%, and the 30-day disintegration rate reaches more than 98%.

[0019] The present invention also provides a method for preparing a heterogeneous synergistically degradable polyester fiber as described above, comprising the following steps:

[0020] (1) preparing a degradation-promoting masterbatch composed of a polymer containing a hydrophilic group and polyethylene terephthalate;

[0021] (2) Polyethylene terephthalate, nano-titanium dioxide, silicone, degradation-promoting masterbatch and degradation masterbatch were placed in a vacuum oven at 140-150° C. and dried for 6 h, mixed evenly and added to the hopper of a melt spinning machine;

[0022] (3) Using a spinneret with a zigzag spinneret hole, the shaped synergistically degradable polyester fiber is extruded through a screw extruder.

[0023] As the preferred technical solution:

[0024] In the method as described above, step (1) specifically comprises: the content of the polymer containing the hydrophilic group in the degradation-promoting masterbatch is 20-50 wt % by weight.

[0025] In the above method, in step (2), the content of the degradation-promoting masterbatch in the mixture is 3-7 wt %, and the content of the degradation masterbatch is 1-3 wt %.

[0026] Beneficial effects:

[0027] (1) The heterotypic synergistically degradable polyester fiber of the present invention contains a certain amount of polymer containing hydrophilic groups, which can improve the affinity of the polyester fiber itself with water, enhance the accessibility of microorganisms and enzymes to the polyester fiber, and enhance the effect of microorganisms and enzymes on the polyester fiber, thereby improving the degradation efficiency;

[0028] (2) The cross-section of the heterogeneous synergistically degradable polyester fiber of the present invention is zigzag-shaped. Since a large number of stress concentration areas are easily generated in the zigzag structure, microcracks are more easily formed during the degradation process due to the action of these stresses, providing more pathways for microorganisms, enzymes, etc. to enter the interior of the fiber, thereby accelerating the degradation process. Under composting conditions, the 30-day degradation rate of the heterogeneous synergistically degradable polyester fiber reaches more than 80%. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The cross section of the shaped synergistically degradable polyester fiber of the present invention having 10 teeth; wherein H is the tooth height of the sawtooth shape. DETAILED DESCRIPTION

[0030] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0031] The following are the manufacturers and the trade names of the raw materials in the examples:

[0032] Ethylene terephthalate-dimethyl isophthalate-5-sodium sulfonate copolymer: CAS number is 104677-82-9;

[0033] Diphenylsilanediol: CAS number is 947-42-2;

[0034] Methacryloxypropyltrimethoxysilane: CAS number is 2530-85-0;

[0035] Polyethylene terephthalate: The manufacturer is Yizheng Chemical Fiber, and the brand is FG600.

[0036] The following is the test method of the performance in the embodiment:

[0037] Disintegration rate: measured according to GB / T 19811-2005;

[0038] Degradation rate: measured in accordance with GB / T19277.1-2011.

[0039] Example 1

[0040] A method for preparing a special-shaped synergistically degradable polyester fiber, comprising the following steps:

[0041] (1) Preparation of raw materials:

[0042] Polymer containing hydrophilic groups: ethylene terephthalate-dimethyl isophthalate-5-sodium sulfonate copolymer;

[0043] polyethylene terephthalate;

[0044] Nano-titanium dioxide: The manufacturer is Anhui Shangmeiheng Nanomaterials Co., Ltd., the brand is PT-Ti01;

[0045] Silicone: diphenylsilanediol;

[0046] Degradable masterbatch: The manufacturer is Shandong Huali Environmental Protection Engineering Co., Ltd., the brand is

[0047] (2) preparing degradation-promoting masterbatch;

[0048] The polymer containing a hydrophilic group and polyethylene terephthalate are uniformly mixed to obtain a degradation-promoting masterbatch; wherein the content of the polymer containing a hydrophilic group in the obtained degradation-promoting masterbatch is 20 wt%;

[0049] (3) Polyethylene terephthalate, nano-titanium dioxide, silicone, degradation-promoting masterbatch and degradation masterbatch were placed in a vacuum oven and dried at 140°C for 6 hours, mixed evenly and added to the hopper of a melt spinning machine, wherein the content of the degradation-promoting masterbatch in the mixture was 7 wt% and the content of the degradation masterbatch was 1 wt%;

[0050] (4) A spinneret with a zigzag spinneret hole is used to extrude a shaped synergistically degradable polyester fiber through a screw extruder; wherein the tooth height of the zigzag spinneret hole is 0.2 times the diameter of the circumscribed circle of the zigzag shape, and the number of teeth of the zigzag shape is 5.

[0051] The cross-section of the finally prepared shaped synergistically degradable polyester fiber is zigzag-shaped, and the tooth height of the zigzag is 0.19 times the diameter of the circumscribed circle of the zigzag. The specification of the shaped synergistically degradable polyester fiber is 20D / 8F, the content of nano-titanium dioxide in the fiber is 1wt%, and the content of silicone in the fiber is 1wt%. Under composting conditions, the 30-day degradation rate of the shaped synergistically degradable polyester fiber reaches 81.3%, and the 30-day disintegration rate reaches 98.2%.

[0052] Comparative Example 1

[0053] A method for preparing a heterogeneous synergistically degradable polyester fiber is basically the same as that in Example 1, except that the tooth height of the serrated spinneret in step (4) is 0.6 times the diameter of the circumscribed circle of the serrated spinneret.

[0054] The cross-section of the final prepared heteromorphic synergistically degradable polyester fiber is zigzag-shaped, the tooth height of the zigzag is 0.1 times the diameter of the circumscribed circle of the zigzag, and the number of teeth is 5. Under composting conditions, the 30-day degradation rate of the heteromorphic synergistically degradable polyester fiber reaches 58.5%, and the 30-day disintegration rate reaches 79.2%.

[0055] By comparing Example 1 and Comparative Example 1, it can be seen that the serrated tooth height of the spinneret in Comparative Example 1 is too high, which will cause the teeth to re-bond together after the melt is extruded through the spinneret, losing the original serrated shape. This is because the melt has a certain expansion effect after being extruded. When the serration height is too high, the melt at the serrated tooth groove expands and bonds after bonding, and cannot form an effective stress concentration area, thereby affecting the degradation efficiency.

[0056] Comparative Example 2

[0057] A method for preparing a heterogeneous synergistically degradable polyester fiber is basically the same as that in Example 1, except that the tooth height of the serrated spinneret in step (4) is 0.1 times the diameter of the circumscribed circle of the serrated spinneret.

[0058] The cross-section of the final prepared heteromorphic synergistically degradable polyester fiber is zigzag-shaped, the tooth height of the zigzag is 0.08 times the diameter of the circumscribed circle of the zigzag, and the number of teeth is 5. Under composting conditions, the 30-day degradation rate of the heteromorphic synergistically degradable polyester fiber reaches 55.3%, and the 30-day disintegration rate reaches 74.8%.

[0059] By comparing Example 1 and Comparative Example 2, it can be seen that the serrated tooth height of the spinneret in Comparative Example 2 is too low, which will result in a low degree of fiber irregularity. This is because after the melt is ejected through the spinneret, during the stretching process, the outer layer is stretched more than the inner layer, making the height of the serration less than 0.1 times the diameter of the circumscribed circle. The stress formed in the serrated area of ​​the fiber is small, resulting in a decrease in degradation efficiency.

[0060] Comparative Example 3

[0061] A method for preparing a heterogeneous synergistically degradable polyester fiber is basically the same as that in Example 1, except that the number of serrated teeth of the spinneret in step (4) is 22.

[0062] The cross-section of the final heteromorphic synergistically degradable polyester fiber is serrated, the tooth height of the serrated shape is 0.11 times the diameter of the circumscribed circle of the serrated shape, and the number of teeth is 16. Under composting conditions, the 30-day degradation rate of the heteromorphic synergistically degradable polyester fiber reaches 78.8%, and the 30-day disintegration rate reaches 86.2%.

[0063] By comparing Example 1 and Comparative Example 3, it can be seen that the number of serrated teeth of the spinneret in Comparative Example 3 is too large, which will cause the bottom of the serrations to stick after the melt is extruded through the spinneret, resulting in a decrease in the height of the serrations. When adhesion occurs, the stress in the fiber will also be partially released, resulting in a decrease in degradation efficiency. This is because the larger the number of serrations, the smaller the tooth pitch between two adjacent serrations, and the melt expands to a certain extent after being extruded through the spinneret. If the tooth pitch is too small, the melt will stick together at the tooth groove after expansion, resulting in a decrease in the height of the serrations and a decrease in the number of serrations. The formed serrations also lose their original serration shape due to adhesion, and the stress is released in large quantities, which reduces the area where microcracks can be formed during degradation, resulting in a decrease in degradation efficiency.

[0064] Comparative Example 4

[0065] A method for preparing heterotypic synergistically degradable polyester fibers is basically the same as that in Example 1, except that the number of serrated teeth of the spinneret in step (4) is 4.

[0066] The cross-section of the final prepared heteromorphic synergistically degradable polyester fiber is zigzag-shaped, the tooth height of the zigzag is 0.19 times the diameter of the circumscribed circle of the zigzag, and the number of teeth is 4. Under composting conditions, the 30-day degradation rate of the heteromorphic synergistically degradable polyester fiber reaches 77.6%, and the 30-day disintegration rate reaches 82.3%.

[0067] By comparing Example 1 and Comparative Example 4, it can be seen that the number of serrated teeth of the spinneret in Comparative Example 4 is too small, which will lead to a reduction in the area where stress concentration can be formed in the fiber, affecting the degradation efficiency. This is because the stress concentration area in the fiber is mainly formed at the serrations, and the number of serrations determines the number and size of the stress concentration areas.

[0068] Comparative Example 5

[0069] A method for preparing a heterotypic synergistically degradable polyester fiber is basically the same as that in Example 1, except that in step (3), the content of the degradation-promoting masterbatch in the mixture is 1 wt%.

[0070] The content of the polymer containing hydrophilic groups in the finally prepared heterotypic synergistically degradable polyester fiber is 0.2wt%. Under composting conditions, the 30-day degradation rate of the heterotypic synergistically degradable polyester fiber reaches 36.4%, and the 30-day disintegration rate reaches 48.3%.

[0071] By comparing Example 1 and Comparative Example 5, it can be seen that the content of the polymer containing hydrophilic groups in the heterotypic synergistically degradable polyester fiber in Comparative Example 5 is too low, which will lead to a decrease in the hydrophilicity of the fiber, resulting in a weakening of the effect of microorganisms, enzymes, etc. on the fiber, affecting the degradation efficiency. This is because microorganisms, enzymes, etc. are all hydrophilic substances. The poor hydrophilicity of the fiber will lead to a weakening of the effect of microorganisms, enzymes, etc. on the fiber, thereby reducing the degradation efficiency.

[0072] Example 2

[0073] A method for preparing a special-shaped synergistically degradable polyester fiber is basically the same as Example 1, except that nano-titanium dioxide and organic silicon are not added in step (3).

[0074] The cross-section of the finally prepared shaped synergistically degradable polyester fiber is serrated, and the tooth height of the serrated shape is 0.19 times the diameter of the circumscribed circle of the serrated shape. The specification of the shaped synergistically degradable polyester fiber is 100D / 18F. Under composting conditions, the 30-day degradation rate of the shaped synergistically degradable polyester fiber reaches 82.7%, and the 30-day disintegration rate reaches 98.5%.

[0075] Example 3

[0076] A method for preparing a special-shaped synergistically degradable polyester fiber, comprising the following steps:

[0077] (1) Preparation of raw materials:

[0078] Polymer containing hydrophilic groups: ethylene terephthalate-dimethyl isophthalate-5-sodium sulfonate copolymer;

[0079] polyethylene terephthalate;

[0080] Nano titanium dioxide: The manufacturer is Anhui Shangmeiheng Nanomaterials Co., Ltd., the brand is PT-Ti03;

[0081] Silicone: diphenylsilanediol;

[0082] Degradable masterbatch: The manufacturer is Shandong Huali Environmental Protection Engineering Co., Ltd., brand

[0083] (2) preparing degradation-promoting masterbatch;

[0084] The polymer containing a hydrophilic group and polyethylene terephthalate are uniformly mixed to obtain a degradation-promoting masterbatch; wherein the content of the polymer containing a hydrophilic group in the obtained degradation-promoting masterbatch is 40 wt%;

[0085] (3) Polyethylene terephthalate, nano-titanium dioxide, silicone, degradation-promoting masterbatch and degradation masterbatch were placed in a vacuum oven and dried at 140°C for 6 hours, mixed evenly and added to the hopper of a melt spinning machine, wherein the content of the degradation-promoting masterbatch in the mixture was 5 wt% and the content of the degradation masterbatch was 3 wt%;

[0086] (4) A spinneret with a zigzag spinneret hole is used to extrude a special-shaped synergistic degradable polyester fiber through a screw extruder; wherein the tooth height of the zigzag spinneret hole is 0.4 times the diameter of the circumscribed circle of the zigzag shape, and the number of teeth of the zigzag shape is 10.

[0087] The cross section of the finally obtained heterotypic synergistically degradable polyester fiber is zigzag-shaped, as shown in FIG. Figure 1 As shown, the tooth height of the serrated shape is 0.37 times the diameter of the circumscribed circle of the serrated shape, the specification of the heterotypic synergistically degradable polyester fiber is 300D / 96F, the content of nano-titanium dioxide in the fiber is 2wt%, and the content of organic silicon in the fiber is 2wt%. Under composting conditions, the 30-day degradation rate of the heterotypic synergistically degradable polyester fiber reaches 85.6%, and the 30-day disintegration rate reaches 98.8%.

[0088] Example 4

[0089] A method for preparing a special-shaped synergistically degradable polyester fiber, comprising the following steps:

[0090] (1) Preparation of raw materials:

[0091] Polymer containing hydrophilic groups: ethylene terephthalate-dimethyl isophthalate-5-sodium sulfonate copolymer;

[0092] polyethylene terephthalate;

[0093] Nano-titanium dioxide: manufacturer Shenzhen Jingcai Chemical Co., Ltd., brand JC-T200;

[0094] Silicone: Methacryloxypropyltrimethoxysilane;

[0095] Degradable masterbatch: The manufacturer is Shandong Huali Environmental Protection Engineering Co., Ltd., brand

[0096] (2) preparing degradation-promoting masterbatch;

[0097] The polymer containing a hydrophilic group and polyethylene terephthalate are uniformly mixed to obtain a degradation-promoting masterbatch; wherein the content of the polymer containing a hydrophilic group in the obtained degradation-promoting masterbatch is 50 wt%;

[0098] (3) Polyethylene terephthalate, nano-titanium dioxide, silicone, degradation-promoting masterbatch and degradation masterbatch were placed in a vacuum oven and dried at 140°C for 6 hours, mixed evenly and added to the hopper of a melt spinning machine, wherein the content of the degradation-promoting masterbatch in the mixture was 7 wt% and the content of the degradation masterbatch was 2 wt%;

[0099] (4) A spinneret with a zigzag spinneret hole is used to extrude a shaped synergistically degradable polyester fiber through a screw extruder; wherein the tooth height of the zigzag spinneret hole is 0.3 times the diameter of the circumscribed circle of the zigzag shape, and the number of teeth of the zigzag shape is 20.

[0100] The cross-section of the finally prepared shaped synergistically degradable polyester fiber is zigzag-shaped, and the tooth height of the zigzag is 0.26 times the diameter of the circumscribed circle of the zigzag. The specification of the shaped synergistically degradable polyester fiber is 120D / 18F, the content of nano-titanium dioxide in the fiber is 3wt%, and the content of silicone in the fiber is 5wt%. Under composting conditions, the 30-day degradation rate of the shaped synergistically degradable polyester fiber reaches 88.2%, and the 30-day disintegration rate reaches 99.1%.

[0101] Example 5

[0102] A method for preparing a special-shaped synergistically degradable polyester fiber, comprising the following steps:

[0103] (1) Preparation of raw materials:

[0104] Polymer containing hydrophilic groups: ethylene terephthalate-dimethyl isophthalate-5-sodium sulfonate copolymer;

[0105] polyethylene terephthalate;

[0106] Nano-titanium dioxide: The manufacturer is Anhui Shangmeiheng Nanomaterials Co., Ltd., the brand is PT-Ti01;

[0107] Silicone: Methacryloxypropyltrimethoxysilane;

[0108] Degradable masterbatch: The manufacturer is Shandong Huali Environmental Protection Engineering Co., Ltd., brand

[0109] (2) preparing degradation-promoting masterbatch;

[0110] The polymer containing a hydrophilic group and polyethylene terephthalate are uniformly mixed to obtain a degradation-promoting masterbatch; wherein the content of the polymer containing a hydrophilic group in the obtained degradation-promoting masterbatch is 50 wt%;

[0111] (3) Polyethylene terephthalate, nano-titanium dioxide, silicone, degradation-promoting masterbatch and degradation masterbatch were placed in a vacuum oven and dried at 150°C for 6 hours, mixed evenly and added to the hopper of a melt spinning machine, wherein the content of the degradation-promoting masterbatch in the mixture was 3 wt% and the content of the degradation masterbatch was 1 wt%;

[0112] (4) A spinneret with a zigzag spinneret hole is used to extrude a special-shaped synergistic degradable polyester fiber through a screw extruder; wherein the tooth height of the zigzag spinneret hole is 0.3 times the diameter of the circumscribed circle of the zigzag shape, and the number of teeth of the zigzag shape is 10.

[0113] The cross-section of the finally prepared shaped synergistically degradable polyester fiber is zigzag-shaped, and the tooth height of the zigzag is 0.28 times the diameter of the circumscribed circle of the zigzag. The specification of the shaped synergistically degradable polyester fiber is 100D / 18F, the content of nano-titanium dioxide in the fiber is 3wt%, and the content of silicone in the fiber is 5wt%. Under composting conditions, the 30-day degradation rate of the shaped synergistically degradable polyester fiber reaches 84.5%, and the 30-day disintegration rate reaches 98.6%.

Claims

1. A special-shaped collaboratively degradable polyester fiber, characterized in that: The invention relates to a polyester fiber comprising not less than 1 wt% of a polymer containing a hydrophilic group, wherein the polymer containing the hydrophilic group is a copolymer of ethylene terephthalate-dimethyl isophthalate-5-sodium sulfonate. Under composting conditions, the 30-day degradation rate of the shaped synergistically degradable polyester fiber reaches more than 80%, and the 30-day disintegration rate reaches more than 98%. The shaped synergistically degradable polyester fiber is extruded through a screw extruder using a spinneret having serrated spinnerets, wherein the tooth height of the serrated spinnerets is 0.2-0.4 times the diameter of the circumscribed circle of the serrated spinneret, and the number of teeth in the serrated spinneret is 5-20.

2. The special-shaped synergistically degradable polyester fiber according to claim 1, characterized in that: The content of the polymer containing hydrophilic groups is not higher than 3.5 wt %.

3. The special-shaped synergistically degradable polyester fiber according to claim 1, characterized in that: It also contains 1-3wt% of nano titanium dioxide and 1-5wt% of organic silicon.

4. The special-shaped synergistically degradable polyester fiber according to claim 3, characterized in that: The organosilicon is diphenylsilanediol or methacryloxypropyltrimethoxysilane.

5. The special-shaped synergistically degradable polyester fiber according to any one of claims 1 to 4, characterized in that: The specifications of the special-shaped synergistic degradable polyester fiber are 20-300D / 8-96F, and the fineness is 2.77-4.63dtex.

6. A method for preparing a special-shaped synergistically degradable polyester fiber according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Preparing a degradation-promoting masterbatch composed of a polymer containing a hydrophilic group and polyethylene terephthalate; (2) Drying polyethylene terephthalate, nano titanium dioxide, organosilicon, degradation-promoting masterbatch and degradation masterbatch, mixing them evenly and adding them into the hopper of the melt spinning machine; (3) Using a spinneret with zigzag spinneret holes, the shaped synergistically degradable polyester fibers are extruded through a screw extruder.

7. The method according to claim 6, characterized in that Step (1) specifically comprises: the content of the polymer containing the hydrophilic group in the degradation-promoting masterbatch is 20-50 wt % by weight.

8. The method according to claim 6, characterized in that In step (2), the content of the degradation-promoting masterbatch in the mixture is 3-7 wt %, and the content of the degradation masterbatch is 1-3 wt %.

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