Biodegradable PAET / PGA blended sheath-core composite fiber and preparation method thereof

Abstract

The invention discloses a biodegradable PAET / PGA blended skin-core composite fiber which is prepared by taking PAET as a skin layer and a blend of PAET and PGA as a core layer through a skin-core composite melt spinning process. Wherein the mass ratio of the skin layer to the core layer is (1: 9)-(3: 7), and the mass fraction of PGA in the PAET and PGA blend forming the core layer is 5-15%. The preparation method comprises the following steps: (1) drying; (2) respectively melting and extruding the skin layer PAET slice and the core layer PAET and PGA blend through a screw extruder to prepare continuous nascent fibers; (3) carrying out circular blowing cooling treatment on the nascent fiber; (4) drafting and winding the cooled nascent fiber; and (5) preparing the PAET / PGA blended sheath-core composite fiber. The environment-friendly plastic has good biodegradability, meets the requirements of different fields while reducing environmental pollution, gives consideration to both mechanical properties and service life, and achieves the purposes of environmental protection and ecology.

Description

Technical Field

[0001] The invention belongs to the technical field of functional composite fibers, and in particular relates to a biodegradable PAET / PGA blended sheath-core composite fiber and a preparation method thereof. Background Art

[0002] With the strengthening of environmental protection policies and the improvement of environmental awareness, the research and application of degradable synthetic fibers have gradually matured. As we all know, fiber materials are the basic raw materials of the textile industry. The technological innovation of fiber materials continues to give new vitality to the textile industry. At present, synthetic fibers made of polymer compounds, such as polyester, nylon, acrylic, chlorofiber, vinylon, spandex, polyolefin stretch yarn, etc., have been widely used in home textiles, clothing, construction, agriculture, automobiles, medical and other fields due to their stable chemical structure and excellent mechanical properties.

[0003] Among them, due to the environmental characteristics and the requirements for environmental sustainability, fibers are required to have degradable properties in many fields. For example, in the field of life, degradable fibers are widely used in textiles, clothing, bedding, decorations, etc. These fibers are soft and comfortable, not easy to generate static electricity, harmless to human health, and can be naturally decomposed after reaching the end of their service life, reducing processing costs while also reducing environmental pollution. In the medical field, degradable synthetic fibers are used to prepare sutures, syringes, and diagnostic materials. These materials can gradually degrade in the body, reducing the need for secondary surgery, and are environmentally friendly. Medical supplies made of biodegradable fibers can decompose naturally after use, reducing the problem of medical waste disposal. In the field of packaging, the application of degradable synthetic fibers can effectively reduce the pollution of plastic waste. These materials can degrade naturally after being discarded and will not cause long-term pollution to the environment. In the agricultural field, degradable synthetic fibers are used to make covering films, fishing nets, and woven fabrics. These materials can degrade naturally after use, reducing the burden on the environment.

[0004] Although synthetic fibers have excellent physical and chemical properties, they are generally considered to be non-degradable materials because they are difficult to decompose in the natural environment. However, with the increasing awareness of environmental protection and the pursuit of sustainable development, degradable synthetic fibers have gradually become one of the research hotspots. Degradable synthetic fibers refer to man-made fibers that meet environmentally friendly requirements. They can be decomposed by microorganisms under certain specific conditions and eventually converted into natural elements instead of polluting the environment. Currently, degradable synthetic fibers include polylactic acid fibers, polyhydroxyalkanoate fibers, starch-based fibers, etc. These fibers can be decomposed by microorganisms under certain specific conditions and will not cause damage to the environment. The current patented technologies for degradable synthetic fibers are as follows:

[0005] CN 115852520 A discloses a method for preparing high-strength biodegradable polyester fiber. The method comprises the following steps: adding ionic copolyester to biodegradable polyester for melt spinning to prepare high-strength biodegradable polyester fiber; the addition amount of ionic copolyester is 1-10% of the mass of biodegradable polyester; the ionic copolyester is composed of nonionic polyester segments and sulfonate ion polyester segments, and different nonionic polyester segments, different ionic polyester segments and nonionic polyester segments and ionic polyester segments are connected by ester bonds; the repeating unit of nonionic polyester segment is 4-10, and the repeating unit of sulfonate ion polyester segment is 2-8; and the intrinsic viscosity of the ionic copolyester is 0.55-0.85dl / g.

[0006] CN117947542A discloses a polyglycolic acid composite fiber with controllable degradation rate and a preparation method thereof, which comprises a degradable fiber-forming polymer and polyglycolic acid (PGA), wherein the degradable fiber-forming polymer is one or more of poly-L-lactic acid, poly-D-lactic acid, stereocomplex polylactic acid, or poly(butylene adipate-terephthalate).

[0007] CN118292138A discloses a biodegradable fiber and its preparation method and application. The raw material composition of the biodegradable fiber includes 80 to 99 parts by weight of polyester-polycarbonate propylene-polyester triblock copolymer; 0.1 to 5.0 parts of modifier; 0.05 to 8.00 parts of auxiliary agent, and the modifier is selected from long carbon chain aliphatic polyamide and / or polylysine.

[0008] It can be seen from the above patent technology that the existing degradable synthetic fibers mainly solve the problem of poor fiber molding and poor mechanical properties due to bonding problems in the fiber molding process. Although they have degradable properties, since the above synthetic fibers are exposed to the air during use, they will undergo oxidation reactions and degrade under the action of light and oxygen. At the same time, in a high temperature and high humidity environment, the ester bond is also easy to react with water, resulting in molecular chain breakage and molecular weight reduction, thereby causing degradation or decomposition of the polymer. Its service life is difficult to meet the required requirements and is not suitable for practical application. In addition, adding degradable polylactic acid, polyhydroxyalkanoate and other ingredients to the synthetic fiber will inevitably affect the mechanical properties of the synthetic fiber while giving the synthetic fiber degradable properties, resulting in a decrease in the service life and application performance of the synthetic fiber. It can be seen that the existing degradable synthetic fibers are difficult to take into account the comprehensive capabilities of mechanical properties, service life and degradation performance. Therefore, how to make the synthetic fiber have good biodegradability, reduce environmental pollution, meet the needs of different fields, take into account the comprehensive capabilities of mechanical properties, service life and degradation performance, and promote the textile industry to develop in a more environmentally friendly and sustainable direction to achieve green environmental protection ecological goals. It has become a difficult problem that technicians in the field of functional composite fibers urgently need to solve. Summary of the invention

[0009] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a biodegradable PAET / PGA blended sheath-core composite fiber and a preparation method thereof which has good biodegradability, reduces environmental pollution, meets the needs of different fields, and takes into account comprehensive capabilities such as mechanical properties, service life and degradation performance.

[0010] In order to solve the above technical problems, the technical solution adopted by the present invention is: a biodegradable PAET / PGA blended sheath-core composite fiber, the composite fiber has PAET as the sheath layer and a blend of PAET and PGA as the core layer, and is prepared by a sheath-core composite melt spinning process; wherein the mass ratio of the sheath layer to the core layer is 1:9-3:7, and the mass fraction of PGA in the PAET and PGA blend constituting the core layer is 5-15%.

[0011] The biodegradable PAET / PGA blended sheath-core composite fiber has a mass ratio of the sheath layer to the core layer of 2:8, and a mass fraction of PGA in the blend of PAET and PGA in the core layer is 10%.

[0012] The biodegradable PAET / PGA blended sheath-core composite fiber has a fineness of 1.2 to 3.5 dtex and a breaking strength of 2.0 to 3.2 cN / dtex.

[0013] The above-mentioned biodegradable PAET / PGA blended sheath-core composite fiber has a fineness of 1.8 dtex and a breaking strength of 2.6 cN / dtex.

[0014] In the above-mentioned biodegradable PAET / PGA blended sheath-core composite fiber, the content of polyamide in the PAET used in the sheath layer and the core layer is 10%.

[0015] A method for preparing a biodegradable PAET / PGA blended sheath-core composite fiber comprises the following steps:

[0016] (1) Dry the PAET skin slices and the PAET core and PGA blends under nitrogen protection until the moisture content is less than 20 ppm;

[0017] (2) The skin PAET slices and the core PAET and PGA blend are melt-extruded through a screw extruder, respectively, and after being distributed and metered through their respective melt pipes, they enter the spinning manifold and are spun through a composite spinning assembly to obtain continuous primary fibers;

[0018] (3) cooling the nascent fibers with annular air blowing;

[0019] (4) drawing and winding the spun fibers after cooling;

[0020] (5) Prepare PAET / PGA blended sheath-core composite fiber.

[0021] In the method for preparing the above-mentioned biodegradable PAET / PGA blended sheath-core composite fiber, in the step (2), the spinning box temperature is 260-280°C.

[0022] In the above-mentioned method for preparing the biodegradable PAET / PGA blended sheath-core composite fiber, in the step (2), the melt extrusion temperature of the skin layer screw is set to 260-280°C, and the melt extrusion temperature of the core layer screw is set to 255-275°C.

[0023] In the method for preparing the above-mentioned biodegradable PAET / PGA blended sheath-core composite fiber, in the step (3), the annular air cooling temperature is 18-25°C.

[0024] In the method for preparing the above-mentioned biodegradable PAET / PGA blended sheath-core composite fiber, in the step (4), the drafting multiple of the spun fiber is 1.5-3.0 times, and the winding speed is 1200-3000 m / min.

[0025] The advantages of the biodegradable PAET / PGA blended sheath-core composite fiber and the preparation method thereof of the present invention are as follows: the present invention processes the sheath-core composite fiber by mixing and melting degradable polymers as the core layer raw material, with PAET as the sheath layer and the blend of PAET and PGA as the core layer, and by adding a certain proportion of polyglycolide in the core layer, not only the continuous and stable formation of the fiber and the mechanical strength of the fiber are ensured, but also the biodegradability of the fiber as a whole is improved, and the degradation rate in the natural environment or the recycling process is accelerated. The needs of practical applications or high-performance fields can be met. The preparation method of the present invention is simple to operate, so that the sheath-core fiber has excellent mechanical properties and biodegradability at the same time, which provides a basis for the development of degradable fibers, promotes the textile industry to develop in a more environmentally friendly and sustainable direction, and achieves the purpose of green environmental protection ecology. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the transverse cross-sectional structure of the biodegradable PAET / PGA blended sheath-core composite fiber of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] In the present invention, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the attached drawings; while "inside" and "outside" refer to the outline of the device. In addition, in the description of this application, the term "including" means "including but not limited to". The terms first, second, third, etc. are used only as labels and do not impose numerical requirements or establish an order. The term "plurality" means "two or more".

[0029] like Figure 1 As shown, a biodegradable PAET / PGA blended sheath-core composite fiber is prepared by a sheath-core composite melt spinning process with PAET as the sheath layer 1 and a blend of PAET and PGA as the core layer 2; wherein the mass ratio of the sheath layer 1 to the core layer 2 is 1:9-3:7, and the mass fraction of PGA in the blend of PAET and PGA constituting the core layer 2 is 5-15%.

[0030] The preparation method of the biodegradable PAET / PGA blended sheath-core composite fiber of the present invention comprises the following steps:

[0031] (1) Dry the PAET skin slices and the PAET core and PGA blends under nitrogen protection until the moisture content is less than 20 ppm;

[0032] (2) The skin PAET slices and the core PAET and PGA blend are melt-extruded through a screw extruder, respectively, and after being distributed and metered through their respective melt pipes, they enter the spinning manifold and are spun through a composite spinning assembly to obtain continuous primary fibers;

[0033] (3) cooling the nascent fibers with annular air blowing;

[0034] (4) drawing and winding the spun fibers after cooling;

[0035] (5) Prepare PAET / PGA blended sheath-core composite fiber.

[0036] The PAET / PGA blended sheath-core fiber prepared by the present invention has a fineness of 1.2-3.5 dtex and a breaking strength of 2.0-3.2 cN / dtex. The PAET (polyamide polyester) used in the sheath layer 1 and the core layer 2 is a polyamide polyester with a polyamide content of 10% and a melting point of 235°C-240°C. The PGA (polyglycolide) used in the core layer 2 has an intrinsic viscosity of (±10%) 0.2-2.0 dl / g and a melting point of 220-240°C.

[0037] PAET (polyamide ester) is made by copolymerization of terephthalic acid, ethylene glycol, and caprolactam. PAET fiber has a soft feel, moderate strength, good skin affinity, and good wearing comfort, but PAET fiber has poor biodegradability and a very long degradation cycle in nature. PGA (polyglycolide), also known as polyglycolic acid, is a highly crystalline, biodegradable aliphatic polymer with a fast degradation rate. The present invention mixes PAET and PGA, adds a certain amount of polyglycolide to the polyamide ester of the core layer 2, and reasonably sets the mass ratio of the skin layer 1 and the core layer 2, while taking into account the mechanical properties and service life of the fiber, giving the fiber product a biodegradable characteristic.

[0038] The present application is described in detail below through specific embodiments. The following embodiments are only partial embodiments of the present application and are not limitations of the present application.

[0039] Example 1

[0040] A biodegradable PAET / PGA blended sheath-core composite fiber, the composite fiber has PAET as the sheath layer and a blend of PAET and PGA as the core layer, and is prepared by a sheath-core composite melt spinning process; wherein the mass ratio of the sheath layer to the core layer is 1:9, and the mass fraction of PGA in the blend of PAET and PGA constituting the core layer is 5%. The fineness of the PAET / PGA blended sheath-core fiber is 1.2 dtex, and the breaking strength is 2.0 cN / dtex.

[0041] A method for preparing a biodegradable PAET / PGA blended sheath-core composite fiber comprises the following steps:

[0042] (1) Dry the PAET skin slices and the PAET core and PGA blends under nitrogen protection until the moisture content is less than 20 ppm;

[0043] (2) The skin PAET slices and the core PAET and PGA blend are respectively melt-extruded through a screw extruder, the skin layer screw melt extrusion temperature is set to 260°C, and the core layer screw melt extrusion temperature is set to 255°C, and after being distributed and metered through their respective melt pipes, they enter the spinning manifold, the spinning manifold temperature is 260°C, and are spun through a composite spinning assembly to obtain continuous primary fibers;

[0044] (3) The spun fibers are subjected to annular air cooling treatment at a temperature of 18°C;

[0045] (4) drawing and winding the spun fibers after cooling, wherein the drawing multiple of the spun fibers is 1.5 times and the winding speed is 1200 m / min;

[0046] (5) PAET / PGA blended sheath-core composite fiber with a fineness of 1.2 dtex and a breaking strength of 2.0 cN / dtex was obtained.

[0047] Example 2

[0048] A biodegradable PAET / PGA blended sheath-core composite fiber, the composite fiber has PAET as the sheath layer and a blend of PAET and PGA as the core layer, and is prepared by a sheath-core composite melt spinning process; wherein the mass ratio of the sheath layer to the core layer is 2:8, and the mass fraction of PGA in the blend of PAET and PGA constituting the core layer is 10%. The fineness of the PAET / PGA blended sheath-core fiber is 1.8 dtex, and the breaking strength is 2.6 cN / dtex.

[0049] A method for preparing a biodegradable PAET / PGA blended sheath-core composite fiber comprises the following steps:

[0050] (1) Dry the PAET skin slices and the PAET core and PGA blends under nitrogen protection until the moisture content is less than 20 ppm;

[0051] (2) The skin PAET slices and the core PAET and PGA blend are respectively melt-extruded through a screw extruder, the skin screw melt extrusion temperature is set to 270°C, and the core screw melt extrusion temperature is set to 260°C, and after being distributed and metered through their respective melt pipes, they enter the spinning manifold, the spinning manifold temperature is 265°C, and are spun through a composite spinning assembly to obtain continuous primary fibers;

[0052] (3) The spun fibers are subjected to annular air cooling treatment at a temperature of 20°C;

[0053] (4) drawing and winding the spun fibers after cooling, wherein the drawing multiple of the spun fibers is 1.8 times and the winding speed is 1800 m / min;

[0054] (5) PAET / PGA blended sheath-core composite fiber with a fineness of 1.8 dtex and a breaking strength of 2.6 cN / dtex was obtained.

[0055] Example 3

[0056] A biodegradable PAET / PGA blended sheath-core composite fiber, the composite fiber has PAET as the sheath layer and a blend of PAET and PGA as the core layer, and is prepared by a sheath-core composite melt spinning process; wherein the mass ratio of the sheath layer to the core layer is 3:7, and the mass fraction of PGA in the blend of PAET and PGA constituting the core layer is 15%. The fineness of the PAET / PGA blended sheath-core fiber is 3.5 dtex, and the breaking strength is 3.2 cN / dtex.

[0057] A method for preparing a biodegradable PAET / PGA blended sheath-core composite fiber comprises the following steps:

[0058] (1) Dry the PAET skin slices and the PAET core and PGA blends under nitrogen protection until the moisture content is less than 20 ppm;

[0059] (2) The skin PAET slices and the core PAET and PGA blend are respectively melt-extruded through a screw extruder, the skin screw melt extrusion temperature is set to 280°C, and the core screw melt extrusion temperature is set to 275°C, and after being distributed and metered through their respective melt pipes, they enter the spinning manifold, the spinning manifold temperature is 280°C, and are spun through a composite spinning assembly to obtain continuous primary fibers;

[0060] (3) The spun fibers are subjected to annular air cooling treatment at a temperature of 25°C;

[0061] (4) drawing and winding the spun fibers after cooling, wherein the drawing multiple of the spun fibers is 3.0 times and the winding speed is 3000 m / min;

[0062] (5) PAET / PGA blended sheath-core composite fiber with a fineness of 3.5 dtex and a breaking strength of 3.2 cN / dtex was obtained.

[0063] The present invention uses a sheath-core composite melt spinning process to make the cortex have a good protective effect on the fiber as a whole, which can fully meet the performance of the composite fiber in the normal service life cycle. After the product is discarded, with the destruction of the cortex, the internal PGA first rapidly degrades, and the degradation of PGA drives the collapse of the overall fiber structure, which greatly improves its biodegradation rate. According to tests, the fiber product of the present invention has a biodegradation period of less than 180 days in a composting environment, which greatly improves the biodegradation rate of the fiber and has good development potential and market application prospects.

[0064] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should fall within the protection scope of the present invention.

Claims

1. A biodegradable PAET / PGA blended sheath-core composite fiber, characterized in that: The composite fiber has PAET as the skin layer and a blend of PAET and PGA as the core layer, and is prepared by a skin-core composite melt spinning process; wherein the mass ratio of the skin layer to the core layer is 1:9-3:7, and the mass fraction of PGA in the blend of PAET and PGA constituting the core layer is 5-15%.

2. The biodegradable PAET / PGA blended core-skin composite fiber according to claim 1, characterized in that: The mass ratio of the skin layer to the core layer is 2:8, and the mass fraction of PGA in the blend of PAET and PGA in the core layer is 10%.

3. The biodegradable PAET / PGA blended sheath-core composite fiber according to claim 1, characterized in that: The PAET / PGA blended sheath-core fiber has a fineness of 1.2 to 3.5 dtex and a breaking strength of 2.0 to 3.2 cN / dtex.

4. The biodegradable PAET / PGA blended sheath-core composite fiber according to claim 3, characterized in that: The PAET / PGA blended sheath-core fiber has a fineness of 1.8 dtex and a breaking strength of 2.6 cN / dtex.

5. The biodegradable PAET / PGA blended sheath-core composite fiber according to claim 1, characterized in that: The content of polyamide in the PAET used in the skin layer and the core layer is 10%.

6. A method for preparing the biodegradable PAET / PGA blended sheath-core composite fiber as described in claims 1-5, characterized in that: The steps include: (1) Dry the PAET skin slices and the PAET core and PGA blends under nitrogen protection until the moisture content is less than 20 ppm; (2) The skin PAET slices and the core PAET and PGA blend are melt-extruded through a screw extruder, respectively, and after being distributed and metered through their respective melt pipes, they enter the spinning manifold and are spun through a composite spinning assembly to obtain continuous primary fibers; (3) cooling the nascent fibers with annular air blowing; (4) drawing and winding the spun fibers after cooling; (5) Prepare PAET / PGA blended sheath-core composite fiber.

7. The method for preparing the biodegradable PAET / PGA blended sheath-core composite fiber according to claim 7, characterized in that: In the step (2), the spinning box temperature is 260-280°C.

8. The method for preparing the biodegradable PAET / PGA blended core-skin composite fiber according to claim 7, characterized in that: In the step (2), the melt extrusion temperature of the skin layer screw is set to 260-280°C, and the melt extrusion temperature of the core layer screw is set to 255-275°C.

9. The method for preparing the biodegradable PAET / PGA blended sheath-core composite fiber according to claim 7, characterized in that: In the step (3), the cooling temperature of the annular air is 18-25°C.

10. The method for preparing the biodegradable PAET / PGA blended sheath-core composite fiber according to claim 7, characterized in that: In the step (4), the drafting ratio of the spun fiber is 1.5-3.0 times, and the winding speed is 1200-3000 m / min.

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