A large-scale wet spinning method based on polydiurea solution

Abstract

A large-scale wet spinning method based on polydiurea solution belongs to the technical field of high-performance fiber manufacturing. The method first configures polydiurea elastomer containing a specific polar organic solvent into a spinning stock solution with a preset viscosity and solid content; then, the stock solution is sent into a spinning assembly by a high-precision metering pump to perform diffusion exchange in a coagulation bath to form a nascent fiber. The nascent fiber is stretched and dried to obtain a polydiurea fiber with good orientation, the obtained fiber has a breaking strength of 209.5 MPa and high toughness of 860.1 MJ m ‑3 The method has the advantages of high production efficiency, controllable process parameters, environmental friendliness, etc., and the prepared polydiurea fiber exhibits excellent mechanical properties, chemical corrosion resistance and thermal stability, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention belongs to the field of polymer material processing, and specifically relates to a large-scale wet spinning method based on polydiurea solution. Background Technology

[0002] Polydiurea materials, rich in multiple hydrogen bonds within their molecular chains, exhibit excellent mechanical properties, wear resistance, and energy dissipation capabilities. They hold significant promise in high-performance elastomers, functional fibers, and smart responsive materials. Polydiurea elastic fibers, due to their unique dynamic hydrogen bonding characteristics, show great application potential in torsional heat and refrigeration, self-healing materials, smart fabrics, and impact-resistant composite materials. However, in existing wet spinning processes, the phase separation and solidification of the polydiurea solution in the coagulation bath are influenced by the solvent diffusion rate, the composition of the coagulation system, and intermolecular interactions, easily leading to instability in spinning, increased fiber defects, and fluctuations in mechanical properties.

[0003] Therefore, there is an urgent need to develop a large-scale wet spinning method suitable for polydiurea solutions, which can ensure the stability and continuity of the spinning process while effectively controlling the microstructure and macroscopic properties of the fibers, thereby promoting the engineering application of polydiurea fibers in the fields of high-performance fibers and functional materials. Summary of the Invention

[0004] To address the problems existing in current wet spinning technology, this invention develops a large-scale polydiurea wet spinning method that can stably control the rheological behavior of the spinning solution, optimize the solidification diffusion rate, and is equipped with an efficient online drying system and collection device.

[0005] The technical solution of this invention is:

[0006] A large-scale wet spinning method based on polydiurea solution includes the following steps:

[0007] (1) Preparation of spinning solution. Polydiurea elastomer containing a specific polar organic solvent is prepared into a spinning solution with a preset viscosity and solid content. After degassing, it is used as the spinning solution and loaded into an extrusion device equipped with a precision metering pump.

[0008] (2) Extrusion molding. Start the metering pump and control the spinning solution to pass through the spinneret at a certain flow rate, continuously extruding it into the coagulation bath;

[0009] (3) Coagulation and regeneration. The coagulation bath uses acetonitrile or its solvent, and the path length of the coagulation bath is not less than 1 m, so that the polydiurea spinning solution can fully exchange solvent in the coagulation bath and solidify to form nascent fibers;

[0010] (4) Multi-stage drafting. The nascent fiber is drafted online using a roller-to-roll drafting system. By adjusting the speed ratio of each drafting roller, the molecular chains are induced to align axially along the fiber to enhance the mechanical strength and orientation of the fiber.

[0011] (5) Drying and Collection. The drawn fibers are collected by a winding device, with the winding speed controlled at 40 cm / min. -1 Simultaneously with winding, the fibers are dried using an infrared radiation heating device (such as an infrared lamp) to remove residual solvent and eliminate internal stress. Furthermore, the infrared radiation heating device is an infrared lamp.

[0012] In this invention, the polydiurea elastomer mentioned in step (1) is PMCU. 2000 PMPU 2000 PDBU 2000 PPMU 2000 PmPU 2000 or PpPU 2000 .

[0013] In this invention, the solid content of the polydiurea spinning solution in step (1) is 10-30%.

[0014] In this invention, the solvent in the polydiurea spinning solution in step (1) is dimethylformamide or dimethylacetamide.

[0015] In this invention, the extrusion flow rate of the spinning solution in step (2) is 3.0-15.0 ml / min. -1 .

[0016] In this invention, the coagulation bath described in step (2) comprises acetonitrile, ethyl acetate, methanol, and water. Acetonitrile is preferred.

[0017] In this invention, the drafting system described in step (4) adopts roller-to-roller drafting. By adjusting the speed ratio of each drafting roller, the fiber can obtain a drafting ratio of 1.1-5.0 times.

[0018] In this invention, the rotational speed ratio of each stage of the drawing roller in step (4) is set to 10-25 cm / min for the first stage drawing roller. -1 The speed of the secondary drafting roller is 30-50 cm / min. -1 .

[0019] In this invention, the collection rate in step (5) is 40 cm / min. -1 .

[0020] The present invention also provides polydiurea elastomer fibers prepared by the above method.

[0021] Advantages and beneficial effects of the present invention:

[0022] This invention relates to a wet spinning process based on polydiurea solution, which enables continuous and stable operation of the spinning process, significantly improving fiber forming efficiency. It overcomes the problems of small scale and poor continuity in existing polydiurea fiber preparation methods, and possesses excellent potential for industrial scale-up. The method of this invention can guide the ordered orientation of polydiurea molecular chains and the construction of hydrogen bond structures during wet spinning and subsequent drawing processes, thereby achieving effective control over the fiber's mechanical properties, elastic recovery properties, and fatigue resistance. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the polydiurea solution-scale wet spinning apparatus of the present invention.

[0024] Figure 2 The diagram shows the mechanical properties of the six types of polydiurea fibers of this invention. Detailed Implementation

[0025] The implementation of the present invention will be further illustrated below through embodiments. Figure 1 The experimental setup shown is complete, including an injection pump 1, a spinneret 2, a coagulation bath 3, an infrared radiation heating device 4, a roll-to-roll drafting system 5, and a winding device 6.

[0026] Example 1:

[0027] (1) Preparation of spinning solution. A spinning solution containing N,N-dimethylformamide solvent and polydiurea elastomer with a solid content of 15% by mass was prepared and defoamed before being used as the spinning solution (PMCU). 2000 PMPU 2000 PDBU 2000 ,PPMU 2000 PmPU 2000 or PpPU 2000 ), and load it into an extrusion device equipped with a precision metering pump;

[0028] (2) Extrusion molding. The feedstock is controlled at a rate of 8.0 mL / h using metering pump 1. -1 The flow rate is extruded through a spinneret 2 with a diameter of 0.3 mm. The extruded fine stream enters a tank with a length of 1.2 m in an acetonitrile coagulation bath 3, where it stays in the bath liquid for about 2-3 minutes to fully exchange solvent and solidify into nascent fibers;

[0029] (3) Drafting and Orientation. After leaving the coagulation bath, the nascent fibers enter the roll-to-roll drafting system 5. The speed of the first-stage drafting roll is set to 20 cm / min. -1The speed of the secondary drafting roller is 40 cm / min. -1 The total draw ratio is approximately 2. The orientation of the polydiurea molecular chains is induced through online draw.

[0030] (4) Drying and Collection. The drawn fibers are collected by the winding device 6, with the winding speed controlled at 40 cm / min. -1 An infrared radiation heating device 4 is installed above the winding position. This device is a vertically mounted infrared heating lamp with a power of 365 W. The fiber is irradiated with infrared radiation before entering the winding roller and during the winding process, which realizes the rapid evaporation of the solvent and the drying and shaping of the fiber.

[0031] (5) Performance Testing. The mechanical properties of the six types of polydiurea fibers prepared were tested, and the results are as follows: Figure 2 As shown.

[0032] Example 2:

[0033] (1) Preparation of spinning solution. A spinning solution containing N,N-dimethylformamide solvent and polydiurea elastomer with a solid content of 15% by mass was prepared and defoamed before being used as the spinning solution (PMCU). 2000 PMPU 2000 PDBU 2000 ,PPMU 2000 PmPU 2000 or PpPU 2000 ), and load it into an extrusion device equipped with a precision metering pump;

[0034] (2) Extrusion molding. The feed solution is controlled by metering pump 1 at a rate of 10.0 mL / h. -1 The flow rate is extruded through a spinneret 2 with a diameter of 0.3 mm. The extruded fine stream enters a tank with a length of 1.2 m in an acetonitrile coagulation bath 3, where it stays in the bath for about 2-3 minutes to allow it to fully exchange solvent and solidify into nascent fibers;

[0035] (3) Drafting and Orientation. After leaving the coagulation bath, the nascent fibers enter the roll-to-roll drafting system 5. The speed of the first-stage drafting roll is set to 10 cm / min. -1 The speed of the secondary drafting roller is 40 cm / min. -1 The total draw ratio is approximately 4 times. The orientation of the polydiurea molecular chains is induced through online draw.

[0036] (4) Drying and Collection. The drawn fibers are collected by the winding device 6, with the winding speed controlled at 40 cm / min. -1An infrared radiation heating device 4 is installed above the winding position. This device is a vertically mounted infrared heating lamp with a power of 365 W. The fiber is irradiated with infrared radiation before entering the winding roller and during the winding process, which realizes the rapid evaporation of the solvent and the drying and shaping of the fiber.

[0037] Example 3:

[0038] (1) Preparation of spinning solution. A spinning solution containing N,N-dimethylformamide solvent and polydiurea elastomer with a solid content of 15% by mass was prepared and defoamed before being used as the spinning solution (PMCU). 2000 PMPU 2000 PDBU 2000 ,PPMU 2000 PmPU 2000 or PpPU 2000 ), and load it into an extrusion device equipped with a precision metering pump;

[0039] (2) Extrusion molding. The feed solution is controlled at a rate of 12.0 mL / h using metering pump 1. -1 The flow rate is extruded through a spinneret 2 with a diameter of 0.5 mm. The extruded fine stream enters a tank with a length of 1.2 m in an acetonitrile coagulation bath 3, where it stays in the bath for about 2-3 minutes to allow it to fully exchange solvent and solidify into nascent fibers;

[0040] (3) Drafting and Orientation. After leaving the coagulation bath, the nascent fibers enter the roll-to-roll drafting system 5. The speed of the first-stage drafting roll is set to 25 cm / min. -1 The speed of the secondary drafting roller is 50 cm / min. -1 The total draw ratio is approximately 2. The orientation of the polydiurea molecular chains is induced through online draw.

[0041] (4) Drying and Collection. The drawn fibers are collected by the winding device 6, with the winding speed controlled at 40 cm / min. -1 An infrared radiation heating device 4 is installed above the winding position. This device is a vertically mounted infrared heating lamp with a power of 365 W. The fiber is irradiated with infrared radiation before entering the winding roller and during the winding process, which realizes the rapid evaporation of the solvent and the drying and shaping of the fiber.

[0042] Example 4:

[0043] (1) Preparation of spinning solution. A spinning solution containing N,N-dimethylformamide solvent and polydiurea elastomer with a solid content of 15% by mass was prepared and defoamed before being used as the spinning solution (PMCU). 2000 PMPU 2000PDBU 2000 ,PPMU 2000 PmPU 2000 or PpPU 2000 ), and load it into an extrusion device equipped with a precision metering pump;

[0044] (2) Extrusion molding. The feed solution is controlled at a rate of 14.0 mL / h using metering pump 1. -1 The flow rate is extruded through a spinneret 2 with a diameter of 0.6 mm. The extruded fine stream enters a tank with a length of 1.2 m in an acetonitrile coagulation bath 3, where it stays in the bath for about 2-3 minutes to allow it to fully exchange solvent and solidify into nascent fibers;

[0045] (3) Drafting and Orientation. After leaving the coagulation bath, the nascent fibers enter the roll-to-roll drafting system 5. The speed of the first-stage drafting roll is set to 15 cm / min. -1 The speed of the secondary drafting roller is 45 cm / min. -1 The total draw ratio is approximately 3 times. The orientation of the polydiurea molecular chains is induced through online draw.

[0046] (4) Drying and Collection. The drawn fibers are collected by the winding device 6, with the winding speed controlled at 40 cm / min. -1 An infrared radiation heating device 4 is installed above the winding position. This device is a vertically mounted infrared heating lamp with a power of 365 W. The fiber is irradiated with infrared radiation before entering the winding roller and during the winding process, which realizes the rapid evaporation of the solvent and the drying and shaping of the fiber.

[0047] Example 5:

[0048] (1) Preparation of spinning solution. A spinning solution containing N,N-dimethylformamide solvent and polydiurea elastomer with a solid content of 15% by mass was prepared and defoamed before being used as the spinning solution (PMCU). 2000 PMPU 2000 PDBU 2000 ,PPMU 2000 PmPU 2000 or PpPU 2000 ), and load it into an extrusion device equipped with a precision metering pump;

[0049] (2) Extrusion molding. The feed solution is controlled by metering pump 1 at a rate of 6.0 mL / h. -1 The flow rate is extruded through a spinneret 2 with a diameter of 0.2 mm. The extruded fine stream enters a tank with a length of 1.2 m in an acetonitrile coagulation bath 3, where it stays in the bath for about 2-3 minutes to allow it to fully exchange solvent and solidify into nascent fibers;

[0050] (3) Drafting and Orientation. After leaving the coagulation bath, the nascent fibers enter the roll-to-roll drafting system 5. The speed of the first-stage drafting roll is set to 10 cm / min. -1 The speed of the secondary drafting roller is 30 cm / min. -1 The total draw ratio is approximately 3 times. The orientation of the polydiurea molecular chains is induced through online draw.

[0051] (4) Drying and Collection. The drawn fibers are collected by the winding device 6, with the winding speed controlled at 40 cm / min. -1 An infrared radiation heating device 4 is installed above the winding position. This device is a vertically mounted infrared heating lamp with a power of 365 W. The fiber is irradiated with infrared radiation before entering the winding roller and during the winding process, which realizes the rapid evaporation of the solvent and the drying and shaping of the fiber.

Claims

1. A method for large-scale wet spinning based on polydiurea solution, comprising the following steps: (1) Preparation of spinning solution: Polydiurea elastomer containing a specific polar organic solvent is prepared into a spinning solution with a preset viscosity and solid content. After degassing, it is used as the spinning solution and loaded into an extrusion device with a precision metering pump. (2) Extrusion molding. Start the metering pump and control the spinning solution to pass through the spinneret at a certain flow rate, continuously extruding it into the coagulation bath; (3) Coagulation and regeneration: The coagulation bath uses acetonitrile or its solvent, and the coagulation bath path length is not less than 1 m, so that the polydiurea spinning solution can fully exchange solvent in the coagulation bath and solidify to form nascent fibers. (4) Multi-stage drafting: The nascent fiber is drafted online using a roller-to-roller drafting system. By adjusting the speed ratio of each drafting roller, the molecular chains are induced to align along the fiber axis to enhance the mechanical strength and orientation of the fiber. (5) Drying and Collection: The drawn fibers are collected by a winding device, with the winding speed controlled at 0-100 cm / min. -1 While winding, the fibers are simultaneously dried using an infrared radiation heating device to remove residual solvents and eliminate internal stress.

2. The wet spinning method according to claim 1, characterized in that, The polydiurea elastomer mentioned in step (1) is PMCU. 2000 PMPU 2000 PDBU 2000 PPMU 2000 PmPU 2000 or PpPU 2000 .

3. The wet spinning method according to claim 1, characterized in that, In step (1), the solid content of the polydiurea spinning solution is 10-30%.

4. The wet spinning method according to claim 1, characterized in that, The solvent in the polydiurea spinning solution in step (1) is dimethylformamide or dimethylacetamide.

5. The wet spinning method according to claim 1, characterized in that, The extrusion flow rate of the spinning solution in step (2) is 3.0-15.0 ml / min. -1 .

6. The wet spinning method according to claim 1, characterized in that, The coagulation bath described in step (2) contains acetonitrile, ethyl acetate, methanol, and water.

7. The wet spinning method according to claim 1, characterized in that, The drafting system described in step (4) uses roller-to-roller drafting. By adjusting the speed ratio of each drafting roller, the fiber can obtain a drafting ratio of 1.1 to 5.0 times.

8. The wet spinning method according to claim 1 or 7, characterized in that, In step (4), the rotational speed ratio of each stage of the drafting roller is set to 10-25 cm / min for the first stage drafting roller. -1 The speed of the secondary drafting roller is 30-50 cm / min. -1 .

9. The wet spinning method according to claim 1, characterized in that, The collection rate mentioned in step (5) is 40 cm / min. -1 .

10. Polydiurea elastomer fibers prepared according to any one of claims 1 to 9.

Images