A high-performance nylon and its woven bag products

Abstract

The present invention belongs to the field of polyamides and their products. Specifically, it relates to a high-performance polyamide and its woven bag products. Taking polyamide chips as the main body, by adding a dispersion of aluminum sol and carbon aerogel, a spinning melt is obtained through melting using a screw extruder. The spinning melt is fed into a spinning box for spinning to obtain first fibers; the first fibers are drawn and heat-set at a high temperature to obtain second fibers; the second fibers are subjected to mercapto-functionalization modification to obtain the high-performance polyamide; it has a high breaking strength, and even after long-term high-temperature and high-pressure cooking, the decrease in breaking strength is small, and no obvious performance deterioration phenomenon occurs.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyamide and its products, and particularly relates to a high-performance polyamide and its woven bag products. Background Art

[0002] Polyamide, namely nylon, is a chemically synthesized fiber, scientifically named polyamide fiber (PA), whose main molecular chain contains repeating amide groups (-NHCO-).

[0003] Nylon woven bags are a kind of packaging materials widely used in multiple fields, with various advantages and uses. The main characteristics of nylon woven bags include durability, waterproofness, and lightness. These characteristics have made them widely used in multiple industries such as logistics, moving, agriculture, and chemical engineering.

[0004] Currently, nylon woven bags are generally customized by methods such as film laminating and thickening to meet the needs of specific fields, such as the needs of the special chemical industry.

[0005] For current nylon woven bags, in the field of special chemical production, for example, when packaging solid catalysts for synthesis reactions, due to long-term high-temperature and high-pressure steaming, etc., the strength of the nylon fibers themselves decreases to a certain extent, resulting in obvious performance deterioration.

[0006] Based on this, the present invention is proposed. Summary of the Invention

[0007] The purpose of the present invention is to provide a high-performance polyamide and its woven bag products to solve the above problems.

[0008] On the one hand, a high-performance polyamide takes polyamide chips as the main body, and through adding a dispersion of aluminum sol and carbon aerogel, uses a screw extruder to melt to obtain a spinning melt, sends the spinning melt into a spinning box for spinning to obtain a first fiber; stretches and heat-sets the first fiber at high temperature to obtain a second fiber; conducts mercapto-functionalization modification on the second fiber to obtain the high-performance polyamide.

[0009] A further improvement is that the polyamide chips are crushed to pass through an 80-mesh sieve to obtain polyamide powder, and then mixed and stirred evenly with the dispersion of aluminum sol and carbon aerogel, and after drying, they are sent into a screw extruder for melting.

[0010] A further improvement is that the preparation method of the dispersion of aluminum sol and carbon aerogel includes the following steps:

[0011] Add 2 - 2.6 parts by mass of carbon aerogel to 10 parts by mass of aluminum sol, and stir with a stirring paddle. First, stir at 0 - 1 °C for 15 - 25 min, then while stirring, heat up to 100 °C at a rate of 5 °C / min, keep warm and stir for another 5 - 10 min to obtain the dispersion of the aluminum sol and the carbon aerogel.

[0012] During the preparation of the dispersion of the aluminum sol and the carbon aerogel, since the aluminum sol is very light, it is necessary to stir with a stirring paddle. Use the mechanical stirring force of the stirring paddle to first press the carbon aerogel into the aluminum sol, and finally use the mechanical stirring force to crush and uniformly disperse it.

[0013] For further improvement, the mass ratio between the polyamide powder and the dispersion of the aluminum sol and the carbon aerogel is 100:(3.3 - 3.8).

[0014] For further improvement, the drying temperature is 100 °C and the drying time is 3 - 5 h.

[0015] For further improvement, soak the second fiber in an organic solvent, add ethylene dithiol, and react ultrasonically for 12 - 24 h. After the reaction is completed, filter, wash, and dry to complete the thiol functionalization modification.

[0016] Ultrasonic reaction must be used. If stirred, a large number of broken filaments will appear.

[0017] For further improvement, the mass ratio between the second fiber and ethylene dithiol is 1:1.3.

[0018] For further improvement, the organic solvent is one or more of ethanol, acetone, and toluene.

[0019] For further improvement, the mass ratio between the second fiber and the organic solvent is 1:(30 - 50).

[0020] On the other hand, a woven bag product is made by weaving with the described high-performance polyamide.

[0021] On the other hand, the obtained high-performance polyamide can also be used as a catalyst to catalyze the hydroxylation reaction of phenol.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The high-performance polyamide of the present invention has high breaking strength. Even after long-term high-temperature and high-pressure cooking, the decrease in breaking strength is small (at 100 °C, 2 atmospheres, stirring at 60 r / min, cooking for 240 h, the decrease does not exceed 11%), and no obvious performance deterioration phenomenon occurs.

[0024] 2. The high-performance polyamide of the present invention can also be used as a catalyst for catalyzing the hydroxylation reaction of phenol. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a picture of 24,000 times of the high-performance polyamide fiber in Example 1, and the mercapto-functionalized particles on its surface are shown at the arrow. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0027] Example 1

[0028] 1. Add 2 kg of carbon aerogel to 10 kg of aluminum sol (the content of Al2O3 in the aluminum sol is 25 ± 0.5%), stir with a stirring paddle, first stir at 0 - 1°C for 15 min, and then while stirring, heat up to 100°C at a rate of 5°C / min, keep warm and stir for another 5 min to obtain a dispersion of aluminum sol and carbon aerogel.

[0029] 2. Crush the polyamide chips to pass through an 80-mesh sieve to obtain polyamide powder. Take 10 kg of polyamide powder, mix it with 0.33 kg of the dispersion of aluminum sol and carbon aerogel, stir evenly, dry (the drying temperature is 100°C and the drying time is 3 h), and then send it into a screw extruder for melting to obtain a spinning melt. Send the spinning melt into a spinning box for spinning to obtain the first fiber; perform drawing and high-temperature heat setting on the first fiber to obtain the second fiber.

[0030] 3. Immerse 5 kg of the second fiber in 150 kg of toluene, add 6.5 kg of ethylene dithiol, react ultrasonically for 12 h. After the reaction is completed, filter, wash twice with toluene, and dry to complete the mercapto-functionalization modification to obtain the high-performance polyamide.

[0031] See Figure 1 , mercapto-functionalized particles are loaded on the surface of the polyamide fiber, as shown at the arrow.

[0032] Example 2

[0033] 1. Add 2.6 kg of carbon aerogel to 10 kg of aluminum sol (the content of Al2O3 in the aluminum sol is 25 ± 0.5%), stir with a stirring paddle, first stir at 0 - 1°C for 25 min, and then while stirring, heat up to 100°C at a rate of 5°C / min, keep warm and stir for 10 min to obtain a dispersion of aluminum sol and carbon aerogel.

[0034] 2. Nylon chips are crushed to pass through an 80-mesh sieve to obtain nylon powder. Take 10 kg of nylon powder, mix it with 0.38 kg of the dispersion of aluminum sol and carbon aerogel, stir evenly, dry (the drying temperature is 100 °C and the drying time is 5 h), and then send it into a screw extruder for melting to obtain a spinning melt. The spinning melt is sent into a spinning box for spinning to obtain the first fiber; the first fiber is drawn and heat-set at a high temperature to obtain the second fiber.

[0035] 3. Immerse 5 kg of the second fiber in 250 kg of toluene, add 6.5 kg of ethylene dithiol, react ultrasonically for 24 h. After the reaction is completed, filter, wash 3 times with toluene, and dry. The thiol-functionalization modification is completed to obtain the high-performance nylon.

[0036] Example 3

[0037] In this example, the difference from Example 1 is that the dispersion of aluminum sol and carbon aerogel is not added, and the nylon chips are directly sent into a screw extruder for melting to obtain a spinning melt, and the rest are the same.

[0038] Example 4

[0039] In this example, the difference from Example 1 is that the dispersion of aluminum sol and carbon aerogel is not added, but the control dispersion 1 is used to replace the dispersion of aluminum sol and carbon aerogel, and the rest are the same.

[0040] The preparation method of the control dispersion 1 is as follows:

[0041] Add 2 kg of carbon aerogel to 10 kg of aluminum sol (the content of Al2O3 in the aluminum sol is 25 ± 0.5%), and stir with a stirring paddle at room temperature for 50 min to obtain the control dispersion 1.

[0042] Example 5

[0043] In this example, the difference from Example 1 is that the dispersion of aluminum sol and carbon aerogel is not added, but the control dispersion 2 is used to replace the dispersion of aluminum sol and carbon aerogel, and the rest are the same.

[0044] The preparation method of the control dispersion 2 is as follows:

[0045] Add 2 kg of carbon aerogel to 10 kg of aluminum sol (the content of Al2O3 in the aluminum sol is 25 ± 0.5%), and stir with a stirring paddle at 100 °C for 50 min to obtain the control dispersion 2.

[0046] Example 6

[0047] In this example, the difference from Example 1 is that the aluminum sol is used to replace the dispersion of aluminum sol and carbon aerogel, and the rest are the same.

[0048] In addition, it was found in the experiments that if only carbon aerogel was added, that is, using carbon aerogel to replace the dispersion of aluminum sol and carbon aerogel, a large number of broken filaments would occur during spinning and there would be no spinnability.

[0049] Example 7

[0050] In this example, the difference from Example 1 is that the ethylene dithiol used for thiol-functionalized modification is replaced with β-mercaptoethylamine, and the rest are the same.

[0051] The properties of the high-performance polyamides of Examples 1 to 7 are shown in Table 1:

[0052] Table 1

[0053] Breaking strength (cN / dtex) Breaking strength after long-term high-temperature and high-pressure cooking (cN / dtex) Example 1 8.22 7.32 Example 2 8.5 7.69 Example 3 9.01 2.95 Example 4 5.56 1.38 Example 5 4.73 1.29 Example 6 4.17 0.95 Example 7 3.38 1.99 Reference fiber 1 5.35 3.51 Reference fiber 2 3.59 1.81

[0054] Reference fiber 1 is an existing polyamide fiber. It directly uses polyamide chips and melts them using a screw extruder to obtain a spinning melt. The spinning melt is fed into a spinning box for spinning, and then drawing and high-temperature heat setting are carried out to obtain the fiber.

[0055] Reference fiber 2 is taken from the second fiber in Example 1.

[0056] The breaking strength after long-term high-temperature and high-pressure cooking is measured by cooking at 100 °C and 2 atmospheres. During the cooking process, a stirring paddle is used to stir to pull the fiber, the stirring speed is 60 r / min, and the cooking time is 240 h. After the cooking is completed, the breaking strength of the fiber is measured.

[0057] From the above, it can be seen that doping the polyamide substrate with the dispersion of aluminum sol and carbon aerogel will cause a significant decrease in the breaking strength of the polyamide fiber, while thiol-functionalized modification of the polyamide fiber surface will significantly increase the breaking strength of the fiber.

[0058] When adding aluminum sol and carbon aerogel internally, it is necessary to first disperse the carbon aerogel at a low temperature, and then promote more orderly dispersion by gradually increasing the temperature, and finally prepare a dispersion of aluminum sol and carbon aerogel with high stability.

[0059] Phenol hydroxylation catalytic activity characterization test

[0060] 50 g of phenol, 100 g of hydrogen peroxide with a mass fraction of 36%, and 7 g of high-performance polyamide (Examples 1, 3, 4, 5, 6, 7 and reference fibers 1, 2) are refluxed at 70 °C for 2 h to investigate the influence of different types of high-performance polyamide on the products of the phenol hydroxylation reaction. The results are shown in Table 2:

[0061] Table 2

[0062]

[0063] In Table 2, the blank group refers to the reaction group of phenol and hydrogen peroxide without adding a catalyst.

[0064] As can be seen from Table 2, by adding a dispersion of aluminum sol and carbon aerogel internally and using mercapto-functionalized modified polyamide fiber externally, the obtained high-performance polyamide can also be used to catalyze the hydroxylation reaction of phenol.

[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-performance polyamide, characterized in that: Using nylon chips as the main body, by adding a dispersion of aluminum sol and carbon aerogel, a spinning melt is obtained through melting using a screw extruder, and the spinning melt is fed into a spinning box for spinning to obtain a first fiber; the first fiber is drawn and heat-set at a high temperature to obtain a second fiber; The second fiber is subjected to mercapto-functionalization modification to obtain the high-performance nylon; The nylon chips are pulverized to pass through an 80-mesh sieve to obtain nylon powder, which is then mixed and stirred evenly with a dispersion of aluminum sol and carbon aerogel, dried, and fed into a screw extruder for melting; The preparation method of the dispersion of aluminum sol and carbon aerogel includes the following steps: Add 2-2.6 parts by mass of carbon aerogel to 10 parts by mass of aluminum sol, stir with a stirring paddle, first stir at 0-1 °C for 15-25 min, then while stirring, heat up to 100 °C at a rate of 5 °C / min, keep warm and stir for another 5-10 min to obtain the dispersion of aluminum sol and carbon aerogel; The second fiber is soaked in an organic solvent, ethylenedithiol is added, and ultrasonic reaction is carried out for 12-24 h. After the reaction is completed, filtration, washing, and drying are carried out to complete the mercapto-functionalization modification.

2. The high-performance polyamide according to claim 1, characterized in that: The mass ratio between the nylon powder and the dispersion of aluminum sol and carbon aerogel is 100:(3.3-3.8).

3. A high-performance polyamide according to claim 1, characterized in that: The drying temperature is 100 °C and the drying time is 3-5 h.

4. A high-performance polyamide according to claim 1, wherein: The mass ratio between the second fiber and ethylenedithiol is 1:1.

3.

5. A high-performance polyamide according to claim 1, characterized in that: The organic solvent is one or more of ethanol, acetone, and toluene.

6. A high-performance polyamide according to claim 5, characterized in that: The mass ratio between the second fiber and the organic solvent is 1:(30-50).

7. A woven bag product, characterized in that: It is woven and made using a high-performance nylon according to any one of claims 1-6.

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