CN101532244B - Method for modifying ultrahigh molecular weight polyethylene fiber by plasma treatment - Google Patents

Abstract

The invention relates to a method for modifying ultra-high molecular weight polyethylene fibers by plasma treatment, comprising: (1) preparing silicon dioxide nanoparticles into an organic solvent or water sol with a mass percentage of 0.01-15% through ultrasonic vibration technology or (2) the nano-silica sol solution prepared by hybridizing the precursor solution of organic-inorganic nanoparticles and silica nanoparticles; (3) coating the above-mentioned sol solution on ultra-high molecular weight polyethylene The surface of the fiber is coated by spraying or padding; (4) The ultra-high molecular weight polyethylene fiber is dried at 10-150°C and the solvent is collected, and then the ultra-high molecular weight polyethylene fiber is introduced into the plasma through a plasma generating device Atmosphere zone for plasma surface modification. The composite performance between the ultra-high molecular weight polyethylene fiber and the organic matrix material treated by the invention is greatly improved, the process is simple, the treatment effect is good, the cost is low, the environment pollution is not easy to be caused, and the energy consumption can also be reduced.

Description

Plasma treatment method for modification of ultra-high molecular weight polyethylene fiber

technical field

The invention belongs to the field of preparation of surface modification of ultra-high molecular weight polyethylene fibers, in particular to a method for modifying ultra-high molecular weight polyethylene fibers by plasma treatment.

Background technique

Ultra-high molecular weight polyethylene (UHMWPE) fiber is a high-performance fiber that appeared after carbon fiber and aramid fiber. It is made of ultra-high molecular weight polyethylene, through high-pressure solid-state extrusion method, plasticized melt spinning method, surface crystal growth method, super-stretching or partial super-stretching method, gel spinning-hot stretching method, etc. It is a high-performance fiber with high strength and high modulus. Its relative molecular mass is 1 million to 6 million, its molecular shape is a linear extended chain structure, its orientation degree is close to 100%, its strength is equivalent to about 15 times that of high-quality steel, 2 times higher than carbon fiber, and 40% higher than aramid fiber. , The density is 0.97g/cm3, and it also has excellent properties such as ultraviolet radiation resistance, chemical corrosion resistance, high specific energy absorption, low dielectric constant, high electromagnetic wave transmittance, low friction coefficient and outstanding impact resistance and cutting resistance. Therefore, UHMWPE fiber is ideal for making soft bulletproof clothing, stab-proof clothing, lightweight bulletproof helmets, bulletproof armor for cash transport vehicles, bulletproof armor for helicopters, lightweight high-pressure containers, aerospace structural parts, fishing nets, rowing boats, sailing boats, ski skis, etc. ideal material. However, since the UHMWPE fiber itself is a long linear chain formed by non-polar methylene groups, there is no strong intermolecular force between the fiber molecules; the surface of the fiber is chemically inert, and it is difficult to form a chemical bond with the resin; The smooth surface is caused by high crystallization and high orientation formed by high stretching. The combined effect of all these factors makes the surface energy of the fiber very small, and it is difficult to form a good interfacial bond with the matrix resin when it is used as a reinforcing material of a composite material.

To improve the interfacial bonding strength between UHMWPE fiber and resin matrix, surface coating method, chemical reagent etching, plasma treatment modification, corona discharge treatment, photooxidation surface modification treatment, radiation grafting treatment and other methods can be used to improve the bonding strength. The fiber is modified to activate the inert surface layer of the fiber, and introduce polar groups such as carboxyl, carbonyl, and hydroxyl on the surface of the non-polar fiber. and low temperature plasma treatment. Among them, the low-temperature plasma treatment method has received widespread attention because of its high efficiency and rapidity, no damage to the basic properties of materials, and environmental friendliness.

Chinese patent CN 1431358A simultaneously improves the heat resistance, creep resistance and adhesiveness of high-strength polyethylene fibers by impregnating polyethylene fibers with an organic solution composed of a photosensitizer and a crosslinking agent, and then crosslinking the fibers by ultraviolet radiation; Patent Int.C1D01MI5/00 (2006.01) proposes to use intrinsically conductive polymer monomer pyrrole or thiophene to treat ultra-high molecular weight polyethylene fibers soaked in organic sulfonate iron salt in vacuum to obtain fiber surface modification.

Chinese patent document CN1035308A discloses a method for improving the surface adhesiveness of UHMWPE fibers. It adopts the method of plasma treatment on the surface of UHMWPE fiber. This method can effectively improve the wettability of the fiber to the resin matrix and the surface bonding strength. However, this method requires high equipment conditions and is difficult to industrialize, and improper treatment will significantly reduce the mechanical properties of fibers.

SilVerstein M.S. et al. treated the surface modification method of UHMWPE fiber with chromic acid reagent, and the bonding performance was improved by 6 times. However, this method corrodes the fiber surface and has a great influence on the fiber strength.

US patent document USP6172163 also discloses a method for improving the bonding performance of the fiber surface. This method utilizes the high crystallinity of polyethylene and adopts a purely physical method to dissolve and then recrystallize the amorphous area on the surface of the fiber to form a layer of "molecular brush" on the surface of the fiber. After the UHMWPE fiber processed by this method is combined with resin, the fiber bonding performance has been greatly improved. However, this method also has cumbersome procedures and harsh process conditions, and improper treatment will also cause a significant decline in the mechanical properties of UHMWPE fibers.

Chinese patent document CN1693544A discloses a method for improving the surface adhesiveness of UHMWPE fibers. This method is to dissolve the polar polymer in the conventional extractant of UHMWPE jelly fiber to make a composite extractant, then extract the UHMWPE jelly fiber in the composite extractant, and then process it through post-processing such as stretching to make a viscose UHMWPE fiber with greatly improved joint performance. Although this method can better maintain the original strength of UHMWPE fibers, the improvement of fiber bonding strength is limited, and the ideal and practical goals have not been achieved.

U.S. patent literature LJSP5039549 and USP5755913 disclosed methods are under plasma, ozone, corona discharge or ultraviolet radiation, some polar group-containing monomers (such as acrylic acid, acrylamide, acrylonitrile, etc.) are grafted on the UHMWPE fiber surface. ) surface modification method can greatly improve the surface bonding performance of UHMWPE fibers, but the process is cumbersome, and the best process conditions for grafting treatment are difficult to grasp, and the prospects for industrialization are slim.

Chinese patent CN1035308A discloses a method for improving the surface bonding performance of UHMWPE fibers. It is to conduct plasma treatment on the surface of UHMWPE fibers. This method can effectively improve the wettability and surface bonding strength of fibers to commonly used base materials, but for The thermal and creep properties of the fibers were not affected. However, this patent does not use nano-materials to prepare sol technology, nor does it mention the use of nano-silica sol technology to coat UHMWPE fibers, especially UHMWPE fibers coated with nano-silica sol and then undergo surface modification by plasma technology The above patents are not involved in the method.

Low-temperature plasma is a kind of plasma in a state of non-thermodynamic equilibrium, in which the energy of the particles is generally about several to tens of electron volts, which is greater than the bond energy of the material, and can completely destroy the chemical bonds of the material and form new bonds. The energy is far lower than that of high-energy radioactive rays, which only involves the surface of the material and does not affect the bulk performance of the material. Therefore, normal temperature and atmospheric pressure plasma can improve the chemical reactivity of nanoparticles, and the use of plasma to treat the surface of UHMWPE fiber material coated with nano-silica sol can cause physical and chemical changes on the surface of the material that cannot be achieved by traditional physical and chemical methods. sex.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for modifying ultra-high molecular weight polyethylene fibers by plasma treatment, and the composite performance between the ultra-high molecular weight polyethylene fibers treated by the present invention and organic matrix materials has been greatly improved , the process is simple, the treatment effect is good, the cost is low, the environment pollution is not easy to be caused, and the energy consumption can also be reduced.

A method for plasma treatment of ultra-high molecular weight polyethylene fiber modification of the present invention, comprising:

(1) Silica nanoparticles are prepared into a sol solution of an organic solvent or water with a mass percent concentration of 0.01 to 15% by ultrasonic vibration technology;

or (2) hybridizing the precursor solution of organic-inorganic nanoparticles and silica nanoparticles to obtain a nano-silica sol solution with a concentration of 0.01 to 15% by mass;

(3) above-mentioned sol solution is coated on the ultrahigh molecular weight polyethylene fiber surface, and coating method is the method for spraying or padding;

(4) Dry the ultra-high molecular weight polyethylene fiber at 10-150°C and collect the solvent, then the ultra-high molecular weight polyethylene fiber is introduced into the plasma atmosphere area through the plasma generator for plasma surface modification, and the processing power is 10 ～15000w, the time is 0.5～300 seconds; the processed ultra-high molecular weight polyethylene fiber is wound online in the automatic winding machine, and the speed of the ultra-high molecular weight polyethylene fiber is adjusted by adjusting the speed of the winding shaft. According to the needs of different processing techniques, the distance and speed of ultra-high molecular weight polyethylene fibers passing through the plasma nozzle are adjusted accordingly.

The organic solvent in the described step (1) is hexane, isopentane, n-pentane, sherwood oil, cyclohexane, isooctane, trifluoroacetic acid, trimethylpentane, cyclopentane, heptane, Butyl chloride, butyryl chloride, trichloroethylene, carbon tetrachloride, trichlorotrifluoroethane, toluene, p-xylene, chlorobenzene, o-dichlorobenzene, diethyl ether, benzene, isobutanol, dichloro Methane, ethylene dichloride, n-butanol, methyl isobutyl ketone, tetrahydrofuran, ethyl acetate, isopropanol, chloroform, methyl ethyl ketone, dioxane, pyridine, acetone, nitromethane, acetic acid, acetonitrile , aniline, dimethylformamide, methanol, ethylene glycol, n-octanol, n-hexanol, cyclohexanol, n-propanol, diacetone alcohol, dimethyl sulfoxide DMSO, carbon disulfide, trichloroethane, butanone, Ethylene glycol dimethyl ether, ethylene glycol monomethyl ether or butyl acetate.

The organic nanoparticles in the step (2) are organic compounds with reactive groups, such as anthracene, perylene, polydiacetylene, pyrazoline derivative organic nanocrystals PDDP, DPP, DAP, poly(p-phenylene vinylene PPV), Thiophene oligomer, 1,4-bis-(2-(5-phenyloxazolyl))benzene, small organic molecules of pyrene, nanowires of anthracene, nanotubes of small organic molecules of pyrene, pyrene-polypyrrole, Organic fluorescent dye Nile red, vanadyl phthalocyanine, poly(p-phenylene PPV), styrene St, oleic acid, carboxylic acid, isocyanic acid, polymethacrylic acid, polybutylacrylic acid, polymethacrylic acid PMA, methacrylic acid , polymethylacrylic, silane, diphenylmethane diisocyanate, hexamethylene diisocyanate, phenyl polyisocyanate, toluene diisocyanate polyvinyl acetate, polyacrylate ACR, fatty acid salt, methyl methacrylate Ester MMA, aluminate, titanate and other ester group-containing esters, PVA polyvinyl alcohol and other alcohols, organic molecules such as hexadecyltrimethylammonium bromide, silicon amides, polyaniline, N, N- Amides such as dimethylacetamide and dimethylformamide, polyoxyethylene lauryl ether, poly(N-isopropylacrylamide) grafted polystyrene, PEG grafted polystyrene, PEG grafted polystyrene Methyl methacrylate, polyethylene glycol grafted polystyrene;

The inorganic nanoparticles are selected from one or more of nanoscale metals, nanoscale metal oxides, nanoscale nonmetals, and nanoscale nonmetal oxides;

The nanoscale metal is silver, copper or a mixture thereof;

The nanoscale metal oxide is selected from one or a mixture of oxides of titanium, aluminum, zirconium, iron, tin, zinc, barium, nickel;

The nano-scale non-metal and its oxide are selected from one or a mixture of carbon nanotubes, silicon dioxide, montmorillonite, phosphorus oxide, etc.;

The plasma generating device is a variety of plasma generators, the plasma atmosphere is generated by the plasma generator, and the plasma atmosphere formed by spraying into the atmospheric environment of normal temperature and normal pressure through the nozzle mechanism is applied to industrialized large-scale Production;

The plasma is selected from one or more of helium, argon or functional gas, wherein the molar ratio of helium to argon is 50%-99.99%, and the functional gas is 0.001-30%. forming a plasma atmosphere through the plasma formation region;

The functional gases are SO ₂ , ammonia, oxygen, hydrogen, nitrogen, carbon tetrafluoride, carbon dioxide, methane CH4, ethane C2H6, propane C3H8, butane C4H10, pentane C5H12, hexane C6H14, heptane C7H16, Octane C8H18, Nonane C9H20, Decane C10H22, Undecane C11H24, Dodecane C12H26, Tridecane C13H28, Ethylene (C2H4), Propylene (C3H6), Butene (C4H8), Pentene (C5H10) , hexene (C6H12), propadiene (C3H4), butadiene (C4H6), isoprene (C5H8), hexatriene (C6H8), acetylene (C2H2), propyne (C3H4), butyne ( C4H6), pentyne (C5H8), hexyne (C6H10), heptyne (C7H12), octyne (C8H14), nonyne (C9H16), decyne (C10H18), undecyne (C11H20), tetrafluoroethylene and Silane, various siloxane gases, acrylic acid, methacrylic acid vapor or their combination gases.

Through plasma surface treatment, various physical and chemical changes occur on the surface of the UHMWPE fiber material coated with nano-silica sol, or it is etched and rough, or forms a dense cross-linked layer, or introduces oxygen-containing polar groups, The hydrophilicity, cohesiveness and electrical properties are improved respectively, and the surface of the material is changed from non-polar and difficult to stick to a certain polarity and easy to stick, which is beneficial to bonding and coating.

The following physical and chemical changes occur on the surface of the ultra-high molecular weight polyethylene fiber of the present invention after plasma treatment: (1) part of the chemical bonds on the surface of the ultra-high molecular weight polyethylene fiber and the surface of the nanomaterial surface coated on the surface are broken, forming a high chemical activity (2) The free radicals existing in the plasma state quickly combine with the free radicals on the surface of ultra-high molecular weight polyethylene fibers and the surface of nanomaterials coated on the surface to form new chemical bonds; (3) ultra-high molecular weight polyethylene fibers The surface of the vinyl fiber and the surface of the nanomaterials coated on the surface are bombarded and etched, and the microstructure changes from smooth to rough, which is conducive to the penetration of organic matrix materials such as resin.

Beneficial effect

(1) The infiltration speed of the ultra-high molecular weight polyethylene fiber and matrix resin treated by the present invention is improved, the infiltration amount is increased, and the infiltration effect is improved, so that the molding process and overall comprehensive performance of the composite material are more optimized;

(2) The method is convenient to operate, simple in process, fast in processing speed, good in treatment effect, low in cost, less likely to cause environmental pollution, and can also reduce energy consumption.

Description of drawings

Fig. 1 is the process flow sheet of the surface treatment method of ultra-high molecular weight polyethylene fiber;

Fig. 2 is the contact angle photograph of the UHMWPE fiber treated with helium plasma;

Fig. 3 is the infrared spectrum of the UHMWPE fiber treated with helium plasma;

Figure 4 is a photograph of the contact angle of UHMWPE fibers treated with oxygen plasma

Fig. 5 is the infrared spectrum of the UHMWPE fiber treated with oxygen plasma;

Fig. 6 is the infrared difference spectrum of ultra-high molecular weight polyethylene fibers treated with helium plasma and oxygen plasma.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

Helium plasma treatment of nano-silica sol coated ultra-high molecular weight polyethylene fibers

As shown in Figure 1, the ultra-high molecular weight polyethylene fiber 1 to be treated is immersed in a percentage concentration of 0.05% nano-silica sol along the outer circle of the flower basket of the sol padding device 2, and the padding process is carried out, and then the ultra-high molecular weight polyethylene fiber The ethylene fiber is introduced into the drying device 3, dried at 60°C and the solvent is collected, and then the ultra-high molecular weight polyethylene fiber 1 is introduced into the plasma atmosphere area of the plasma nozzle 4 for plasma surface modification treatment, and the upper surface of the fiber bundle is The distance from the nozzle is 5MM, the distance from the lower surface of the fiber bundle to the nozzle is <20MM, the power is 40 watts, and the processing time is 2 seconds. Rotating speed to adjust the running speed of ultra-high molecular weight polyethylene fiber. According to the needs of different processing techniques, the distance and speed of ultra-high molecular weight polyethylene fibers passing through the plasma nozzle are adjusted accordingly.

Surface treatment effect of ultra-high molecular weight polyethylene fiber: the photo of contact angle is shown in Figure 2, and the infrared spectrum is shown in Figure 3.

Example 2

Oxygen plasma treatment of nano-silica sol coated ultra-high molecular weight polyethylene fibers

As shown in Figure 1, the ultra-high molecular weight polyethylene fiber 1 to be treated is immersed in a percentage concentration of 0.05% nano-silica sol along the outer circle of the flower basket of the sol padding device 2, and the padding process is carried out, and then the ultra-high molecular weight polyethylene fiber The vinyl fiber is introduced into the drying device 3, dried at 110°C and the solvent is collected. Then the ultra-high molecular weight polyethylene fiber 1 is introduced into the plasma atmosphere area of the plasma nozzle 4 to carry out plasma surface modification treatment. The distance between the upper surface of the fiber bundle and the nozzle is 5MM, the distance between the lower surface of the fiber bundle and the nozzle<20MM, and the power is 40 watts. The time is 2 seconds, and the processed ultra-high molecular weight polyethylene fiber 1 is wound on-line in the automatic winder 5, and the speed of the carbon fiber is adjusted by adjusting the speed of the winding shaft. According to the needs of different processing techniques, the distance and speed of ultra-high molecular weight polyethylene fibers passing through the plasma nozzle are adjusted accordingly.

Surface treatment effect of ultra-high molecular weight polyethylene fiber: the photo of contact angle is shown in Figure 4, and the infrared spectrum is shown in Figure 5.

Claims (2)

1. A method for plasma treatment of ultra-high molecular weight polyethylene fiber modification, comprising: (1) Silica nanoparticles are prepared into a sol solution of an organic solvent or water with a mass percent concentration of 0.01 to 15% by ultrasonic vibration technology; (2) above-mentioned sol solution is coated on the ultrahigh molecular weight polyethylene fiber surface, and coating method is the method for spraying or padding; (3) Dry the ultra-high molecular weight polyethylene fiber at 10-150°C and collect the solvent, then the ultra-high molecular weight polyethylene fiber is introduced into the plasma atmosphere area through the plasma generating device for plasma surface modification, and the processing power is 10-100 °C. 15000w, the time is 0.5-300 seconds; the processed ultra-high molecular weight polyethylene fiber is rewound online in an automatic winding machine, and the speed of the ultra-high molecular weight polyethylene fiber is adjusted by adjusting the speed of the winding shaft; The plasma generating device is a variety of plasma generators. The plasma atmosphere is generated by the plasma generator and sprayed into the atmospheric environment of normal temperature and pressure through the nozzle mechanism to form a plasma atmosphere. 2. a kind of method of plasma treatment UHMWPE fiber modification according to claim 1, is characterized in that: the organic solvent in described step (1) is hexane, isopentane, n-pentane , petroleum ether, cyclohexane, isooctane, trifluoroacetic acid, trimethylpentane, cyclopentane, heptane, butyl chloride, butyryl chloride, trichloroethylene, carbon tetrachloride, trichlorotrifluoro Ethane, toluene, p-xylene, chlorobenzene, o-dichlorobenzene, diethyl ether, benzene, isobutanol, methylene chloride, ethylene dichloride, n-butanol, methyl isobutyl ketone, tetrahydrofuran, ethyl acetate , isopropanol, chloroform, methyl ethyl ketone, dioxane, pyridine, acetone, nitromethane, acetic acid, acetonitrile, aniline, dimethylformamide, methanol, ethylene glycol, n-octanol, n-hexanol, Cyclohexanol, n-propanol, diacetone alcohol, dimethyl sulfoxide DMSO, carbon disulfide, trichloroethane, butanone, ethylene glycol dimethyl ether, ethylene glycol monomethyl ether or butyl acetate.

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