An ultrahigh molecular weight polyethylene fiber and a method for producing the same

Abstract

The application discloses a kind of ultra-high molecular weight polyethylene fibers and preparation method thereof, belong to fiber preparation technical field, including following preparation steps: after ultra-high molecular weight polyethylene spinning stock solution is made into gelation pre-oriented silk and is balanced and placed, pretreatment is prepared pretreatment fiber;After pretreatment fiber is soaked in allyl glycidyl ether solution and soaked, the solution on the surface of pretreatment fiber is taken out and dried, and then ultraviolet irradiation is carried out, deionized water is washed, 6 dry and obtain epoxy group grafted fiber;Epoxy group grafted fiber is immersed in polybismaleimide solution, magnetic stirring, deionized water is washed, dried, and polybismaleimide grafted fiber is obtained;Polybismaleimide grafted fiber is sequentially pre-drafted, extracted, dried and positively drafted, and a kind of ultra-high molecular weight polyethylene fiber is obtained.The application enhances the high-temperature resistance of ultra-high molecular weight polyethylene fiber, and the maximum use temperature can reach 180 DEG C.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of fiber preparation, and particularly relates to a kind of ultra-high molecular weight polyethylene fiber and its preparation method. BACKGROUND

[0002] Ultra-high molecular weight polyethylene (UHMW-PE) refers to linear polyethylene without branch chain with viscosity average molecular weight greater than 1.5 million. Ultra-high molecular weight polyethylene fiber is a fiber made of ultra-high molecular weight polyethylene as raw material. The ultra-high molecular weight makes the ultra-high molecular weight polyethylene fiber have excellent properties such as strong wear resistance, good lubricity, high strength, stable chemical properties, and aging resistance. Therefore, the ultra-high molecular weight polyethylene fiber has a wide range of applications in national defense and military equipment (such as bulletproof clothing, helicopter, tank and ship armor, etc.), aerospace (such as wing tip structure of various aircraft, deceleration parachute used when aircraft landing, rope used for aircraft suspension of heavy objects, etc.), civil (such as impact-resistant, anti-corrosion, anti-corrosion coating materials used on the outer surface of ships in marine engineering, anti-corrosion, anti-attachment, wear-resistant materials for various marine building components, pressure vessels used in industry, conveyor belts, filtration materials, dental tray materials used in medical field, etc.), etc.

[0003] However, the melting point of polyethylene material is relatively low, only around 130℃, and the thermal aging speed of ultra-high molecular weight polyethylene fiber under stretching condition is relatively fast, so its maximum use temperature is generally between 80-100℃, which limits its application in high temperature environment. SUMMARY

[0004] The purpose of the present application is to provide an ultra-high molecular weight polyethylene fiber and its preparation method to solve the technical problem of improving the high temperature resistance of the ultra-high molecular weight polyethylene fiber.

[0005] The purpose of the present application can be achieved by the following technical solution:

[0006] A preparation method of an ultra-high molecular weight polyethylene fiber, comprising the following preparation steps:

[0007] Step one: after the ultra-high molecular weight polyethylene spinning solution is made into gelation pre-oriented yarn and balanced and placed, it is immersed in n-heptane for swelling for 6-7h, then taken out, washed with acetone to remove oil and other impurities, dried at 30℃ to constant weight, and pre-treated fiber is obtained;

[0008] Step two: after the pre-treated fiber is immersed in an allyl glycidyl ether solution with a mass fraction of 3-5% for 24h, the solution on the surface of the pre-treated fiber is absorbed with filter paper, and then put into a quartz tube which has been deoxygenated by N2 in advance, ultraviolet irradiation is performed for 15-90min, then washed with deionized water, and dried at 60℃ for 24h to obtain epoxy group grafted fiber.

[0009] Step three: immerse the epoxy group grafted fiber in a 50% mass fraction polybismaleimide solution, magnetically stir at 80℃ for 4-5h, wash with deionized water, dry at 60℃ for 24h, and obtain polybismaleimide grafted fiber;

[0010] Step four: sequentially pre-draft, extract, dry and positively draft the polybismaleimide grafted fiber, and obtain an ultra-high molecular weight polyethylene fiber.

[0011] As a further scheme of the present application, the mass fraction of the ultra-high molecular weight polyethylene in the ultra-high molecular weight polyethylene spinning dope is 5-20%, and the weight average molecular weight of the ultra-high molecular weight polyethylene is 3×10 6 -5×10 6 .

[0012] As a further scheme of the present application, the solvent of the ultra-high molecular weight polyethylene spinning dope is naphthenic oil.

[0013] As a further scheme of the present application, the solvent of the allyl glycidyl ether solution is a mixed solution prepared by mixing 1-hydroxycyclohexyl phenone and methanol at a volume ratio of 3-5:100.

[0014] As a further scheme of the present application, the wavelength of the ultraviolet light for ultraviolet irradiation is all 365nm, and the distance of ultraviolet irradiation is all 15-20cm.

[0015] As a further scheme of the present application, the solvent of the polybismaleimide solution is dimethylformamide.

[0016] An ultra-high molecular weight polyethylene fiber prepared by the above preparation method.

[0017] The beneficial effects of the present application are:

[0018] The present application removes oil and other impurities from the pretreated fiber by performing conventional pretreatment on the gelated pre-oriented yarn made of the ultra-high molecular weight polyethylene spinning dope; then introduces epoxy groups into the pretreated fiber by using ultraviolet light grafting polymerization, and then assembles polybismaleimide in the fiber by using ring-opening polymerization, and finally obtains the ultra-high molecular weight polyethylene fiber by pre-drafting, extracting, drying and positively drafting. Since polybismaleimide is a high-temperature resistant polymer, the high-temperature resistance of the ultra-high molecular weight polyethylene fiber is enhanced, and the maximum use temperature can reach 180℃. DETAILED DESCRIPTION

[0019] With reference to the drawings: the technical solutions in the embodiments of the present application will be clearly and completely described, obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection scope of the present application.

[0020] Embodiment 1

[0021] A preparation method of an ultra-high molecular weight polyethylene fiber, comprising the following preparation steps:

[0022] Step one: after the ultra-high molecular weight polyethylene spinning solution (the mass fraction of the ultra-high molecular weight polyethylene in the ultra-high molecular weight polyethylene spinning solution is 5%, and the weight average molecular weight of the ultra-high molecular weight polyethylene is 3×10 6 , the solvent is naphthenic oil) is made into a gelation pre-oriented yarn and is subjected to an equilibrium standing treatment, then is immersed in n-heptane for swelling for 6 hours, is taken out, is washed with acetone to remove the oil agent and other impurities, and is dried at 30°C to a constant weight to obtain a pretreated fiber;

[0023] Step two: after the pretreated fiber is immersed in an allyl glycidyl ether solution with a mass fraction of 3% (the solvent is a mixed solution prepared by mixing 1-hydroxycyclohexyl phenone and methanol at a volume ratio of 3:100) for 24 hours, the pretreated fiber is taken out and the solution on the surface of the pretreated fiber is absorbed with filter paper, then the pretreated fiber is placed in a quartz tube which is deoxygenated by N2 in advance, is subjected to ultraviolet irradiation for 15 minutes (the wavelength of the ultraviolet light is 365 nm, and the distance of the ultraviolet irradiation is 15 cm), is washed with deionized water, and is dried at 60°C for 24 hours to obtain an epoxy group grafted fiber;

[0024] Step three: the epoxy group grafted fiber is immersed in a polybismaleimide solution with a mass fraction of 50% (the solvent is dimethylformamide), is subjected to magnetic stirring at 80°C for 4 hours, is washed with deionized water, and is dried at 60°C for 24 hours to obtain a polybismaleimide grafted fiber;

[0025] Step four: the polybismaleimide grafted fiber is sequentially subjected to pre-drawing, extraction, drying and drawing to obtain an ultra-high molecular weight polyethylene fiber.

[0026] Comparative example 1

[0027] A preparation method of an ultra-high molecular weight polyethylene fiber, comprising the following preparation steps:

[0028] Step one: after the ultra-high molecular weight polyethylene spinning solution (the mass fraction of the ultra-high molecular weight polyethylene in the ultra-high molecular weight polyethylene spinning solution is 5%, and the weight average molecular weight of the ultra-high molecular weight polyethylene is 3×10 6After gelling and equilibrating the pre-oriented filaments (using naphthenic oil as solvent) and allowing them to stand in equilibrium, they were immersed in n-heptane for swelling for 6 hours, then removed and washed with acetone to remove oil and other impurities. They were then dried at 30°C to constant weight to obtain pretreated fibers.

[0029] Step 2: The pretreated fiber is subjected to pre-stretching, extraction, drying and forward stretching in sequence to obtain an ultra-high molecular weight polyethylene fiber.

[0030] Compared with Example 1, this comparative example omits steps two and three, while the remaining steps and parameters are the same.

[0031] Comparative Example 2

[0032] A method for preparing ultra-high molecular weight polyethylene fiber includes the following preparation steps:

[0033] Step 1: Prepare the ultra-high molecular weight polyethylene (UHMWPE) spinning solution (the mass fraction of UHMWPE in the UHMWPE spinning solution is 5%, and the weight-average molecular weight of UHMWPE is 3 × 10⁻⁶). 6 After gelling and equilibrating the pre-oriented filaments (using naphthenic oil as solvent) and allowing them to stand in equilibrium, they were immersed in n-heptane for swelling for 6 hours, then removed and washed with acetone to remove oil and other impurities. They were then dried at 30°C to constant weight to obtain pretreated fibers.

[0034] Step 2: Immerse the pretreated fibers in a 3% (w / w) allyl glycidyl ether solution (a mixed solution prepared by mixing 1-hydroxycyclohexyl phenyl ketone and methanol in a volume ratio of 3:100) for 24 hours. Remove the fibers and absorb the solution on the surface of the pretreated fibers with filter paper. Place the fibers in a quartz tube that has been deoxygenated by passing N2 through it beforehand. Irradiate them with ultraviolet light for 15 minutes (the ultraviolet light wavelength is 365 nm and the ultraviolet irradiation distance is 15 cm). Wash with deionized water and dry at 60°C for 24 hours to obtain epoxy-grafted fibers.

[0035] Step 3: The epoxy-grafted fiber is subjected to pre-stretching, extraction, drying and forward stretching in sequence to obtain an ultra-high molecular weight polyethylene fiber.

[0036] Compared with Example 1, this comparative example omits step three, while the remaining steps and parameters are the same.

[0037] Example 2

[0038] A method for preparing ultra-high molecular weight polyethylene fiber includes the following preparation steps:

[0039] Step 1: Prepare the ultra-high molecular weight polyethylene (UHMWPE) spinning solution (the mass fraction of UHMWPE in the UHMWPE spinning solution is 20%, and the weight-average molecular weight of UHMWPE is 5 × 10⁻⁶). 6The pretreatment fiber was obtained by the following steps: the gelation pre-oriented yarn was prepared by immersing the yarn in the naphthenic oil solution (the solvent was naphthenic oil), and then the yarn was equilibrated and placed, and then immersed in n-heptane for swelling for 7 hours, and then the yarn was taken out, washed with acetone to remove the oil and other impurities, and dried at 30 °C to constant weight;

[0040] Step two: the pretreatment fiber was immersed in the allyl glycidyl ether solution (the solvent was a mixed solution of 1-hydroxycyclohexyl phenone and methanol with a volume ratio of 5:100) with a mass fraction of 5%, and then the pretreatment fiber was soaked for 24 hours, and then the solution on the surface of the pretreatment fiber was absorbed by filter paper, and then the pretreatment fiber was placed in a quartz tube which was deoxygenated by N2 in advance, and then the pretreatment fiber was ultraviolet irradiated for 90 minutes (the wavelength of the ultraviolet light was 365 nm, and the distance of the ultraviolet irradiation was 20 cm), and then the pretreatment fiber was washed with deionized water, and then the pretreatment fiber was dried at 60 °C for 24 hours, and then the epoxy group grafted fiber was obtained.

[0041] Step three: the epoxy group grafted fiber was immersed in the polybismaleimide solution (the solvent was dimethylformamide) with a mass fraction of 50%, and then the epoxy group grafted fiber was magnetically stirred at 80 °C for 5 hours, and then the epoxy group grafted fiber was washed with deionized water, and then the epoxy group grafted fiber was dried at 60 °C for 24 hours, and then the polybismaleimide grafted fiber was obtained.

[0042] Step four: the polybismaleimide grafted fiber was subjected to pre-drawing, extraction, drying and drawing in sequence, and then the ultrahigh molecular weight polyethylene fiber was obtained.

[0043] The ultrahigh molecular weight polyethylene fiber prepared in Example 1-Example 2 and Comparative Example 1-Comparative Example 2 was subjected to high temperature resistance performance test.

[0044] After the ultrahigh molecular weight polyethylene fiber to be tested was manually opened, 2±0.2 g of the fiber was weighed, and 0.2 g of the fiber was taken out to test the breaking strength f1 according to GB / T 14337, and the remaining fiber was placed in the middle of a constant temperature air drying oven which was heated to 180 °C, and then the fiber was placed at constant temperature for 24 hours, and then the fiber was taken out and cooled to room temperature, and then the breaking stress f2 was tested according to GB / T 14337, and then the breaking strength retention rate λ was calculated according to the following formula:

[0045] λ = f2 / f1 x 100%;

[0046] The test results are shown in Table 1.

[0047] Table 1

[0048] Test item Example 1 Example 2 Comparative Example 1 Comparative Example 2 Breaking strength retention rate λ / % 90.6 92.4 49.6 75.5

[0049] As shown in Table 1, the breaking strength retention rate of the ultrahigh molecular weight polyethylene fiber prepared in Example 1-2 was more than 90% at 180 °C.

[0050] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and illustrative figures, it should be apparent that the scope of the present application is not limited to these specific embodiments.

[0051] While the embodiments of the application have been shown and described herein, it will be understood by those skilled in the art that many changes, modifications, substitutions and alterations to these embodiments can be made without departing from the principles and spirits of the application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing ultra-high molecular weight polyethylene fiber, characterized in that, The preparation steps include the following: Step 1: After preparing gelled pre-oriented filaments from ultra-high molecular weight polyethylene spinning solution and allowing them to stand at equilibrium, the filaments are immersed in n-heptane for swelling for 6-7 hours. After being removed, they are washed with acetone and dried at 30°C to constant weight to obtain pretreated fibers. Step 2: Immerse the pretreated fiber in a 3-5% allyl glycidyl ether solution for 24 hours, then remove it and use filter paper to absorb the solution on the surface of the pretreated fiber. Place it in a quartz tube that has been deoxygenated by passing N2 through it, irradiate it with ultraviolet light for 15-90 minutes, wash it with deionized water, and dry it at 60℃ for 24 hours to obtain epoxy-grafted fiber. The ultraviolet light wavelength for the ultraviolet irradiation is 365nm, and the irradiation distance is 15-20cm. Step 3: Immerse the epoxy-grafted fiber in a 50% (w / w) polybismaleimide solution, stir magnetically at 80°C for 4-5 hours, wash with deionized water, and dry at 60°C for 24 hours to obtain polybismaleimide grafted fiber. Step 4: The polybismaleimide grafted fiber is subjected to pre-stretching, extraction, drying and forward stretching in sequence to obtain an ultra-high molecular weight polyethylene fiber.

2. The method for preparing ultra-high molecular weight polyethylene fiber according to claim 1, characterized in that, The ultra-high molecular weight polyethylene (UHMWPE) spinning solution contains 5-20% UHMWPE by mass, and the weight-average molecular weight of UHMWPE is 3 × 10⁻⁶. 6 -5×10 6 .

3. The method for preparing ultra-high molecular weight polyethylene fiber according to claim 1, characterized in that, The solvent for the ultra-high molecular weight polyethylene spinning solution is naphthenic oil.

4. The method for preparing ultra-high molecular weight polyethylene fiber according to claim 1, characterized in that, The solvent for the allyl glycidyl ether solution is a mixed solution prepared by mixing 1-hydroxycyclohexyl phenyl ketone and methanol at a volume ratio of 3-5:

100.

5. The method for preparing ultra-high molecular weight polyethylene fiber according to claim 1, characterized in that, The solvent for the polybismaleimide solution is dimethylimide.

6. A type of ultra-high molecular weight polyethylene fiber, characterized in that, It is prepared by the preparation method according to any one of claims 1-5.