Functional aramid fiber UD cloth and preparation method thereof

Abstract

The invention relates to the technical field of textiles, and discloses functional aramid fiber UD cloth and a preparation method thereof.The functional aramid fiber UD cloth is formed by taking modified aramid fiber as a base material, gluing the modified aramid fiber with epoxy resin glue, overlapping the modified aramid fiber with a low-density polyethylene film and then curing the modified aramid fiber and the low-density polyethylene film, and the modified aramid fiber is aramid fiber with the surface modified with a macromolecular modifier. The macromolecular modifier structure contains a large number of ether bonds and hydroxyl groups, the ether bonds can generate hydrogen-bond interaction with epoxy resin molecular chains, and the hydroxyl groups can participate in the curing process of epoxy resin glue in the subsequent hot pressing process; the branched structure of the macromolecular modifier can form a hydrogen bond connection site at the interface of the aramid fiber and the glue, and a hydrogen bond connective network is formed, so that the affinity of the aramid fiber and the epoxy resin glue is greatly improved, and the phenomena of layer warping, swelling and the like of the subsequently prepared UD cloth can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of textiles, and in particular to a functional aramid fiber UD cloth and a preparation method thereof. Background Art

[0002] In the field of modern materials science, the development of high-performance fiber materials is changing with each passing day. Among them, aramid fiber, as an important synthetic fiber, has been widely used in many fields due to its excellent physical and chemical properties. Aramid fiber, the full name of which is aromatic polyamide fiber, is a polymer fiber with excellent properties such as high strength, high modulus, high temperature resistance, and chemical corrosion resistance. Aramid fiber UD cloth is a fabric made by arranging aramid fibers in parallel in a single direction (usually warp or weft) and reinforcing them through specific process methods (such as needle punching, sewing or hot pressing). As an important form of aramid fiber, aramid fiber UD cloth has shown great application potential in many fields such as safety protection buffer materials with its unique structure and performance.

[0003] However, aramid fiber itself has a high degree of cleanliness, and the presence of a large number of benzene rings in its structure leads to large steric hindrance. At the same time, the aramid fiber structure itself has fewer active groups, so during the hot pressing process, the adhesion performance with the polymer adhesive is poor. This causes the aramid fiber UD cloth obtained by gluing to easily experience warping, bulging, etc. during use, ultimately greatly shortening the service life of the equipment. Therefore, how to modify aramid fiber and improve its affinity with adhesives has gradually become a research hotspot in recent years. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a functional aramid fiber UD cloth and a preparation method thereof.

[0006] (II) Technical solution

[0007] A method for preparing a functional aramid fiber UD cloth comprises the following steps:

[0008] The first step is to dry the modified aramid fiber, pass through the yarn spreading and pulling device, and then enter the glue tank filled with epoxy resin glue for glue treatment to form glue-containing aramid fiber;

[0009] The second step is to clean the low-density polyethylene film in an ultrasonic instrument and then dry it;

[0010] The third step is to laminate the washed and air-dried low-density polyethylene film with the rubber-containing aramid fiber, and then place it under a temperature of 100-120°C for drying and curing, and then carry out a pulling and winding process to make a single-layer aramid fiber UD cloth;

[0011] The fourth step is to cut the single-layer aramid fiber UD cloth into uniform specifications, and then alternately stack them in the radial / weft direction, and then use a pressing roller for pre-pressing to form a multi-layer aramid fiber UD cloth. Finally, control the hot pressing temperature to 120-150°C and the pressure to 3-5MPa, and perform the pressing roller treatment for 3-5min to obtain the aramid fiber UD cloth.

[0012] As a further embodiment of the present invention, in the first step, the specific preparation method of the modified aramid fiber comprises the following steps:

[0013] Step S1, mixing aramid fiber with 1,4-dichlorobutane, ultrasonicating to form a uniform dispersion, and then using 60 The dispersion is irradiated by a Co irradiation source, and after the irradiation is completed, the fiber material is taken out and separated, and then washed and vacuum dried to form a halogenated aramid fiber;

[0014] Step S2, dispersing the halogenated aramid fiber in toluene, and then adding a macromolecular modifier and a sodium hydroxide solution to the formed dispersion. After the addition, the temperature is controlled to 80-100° C., and the mixture is kept warm for 8-12 hours under continuous stirring. The fiber material is separated to obtain the modified aramid fiber.

[0015] As a further solution of the present invention, in step S1, the irradiation dose during the irradiation treatment is 200 to 1000 KGy.

[0016] As a further embodiment of the present invention, in step S2, the preparation method of the macromolecular modifier is:

[0017] Add hydroxyethyl hexahydro-s-triazine and N,N-dimethylformamide into a polymerization kettle, start stirring, and after a uniform reaction liquid is formed, add 2,7-dibromopyrene and a catalyst into the reaction liquid, stir and mix evenly, then control the heating rate to 2-5°C / min, increase the temperature to 100-120°C, and keep stirring at this temperature for 12-24h, evaporate and remove the solvent, cool and discharge, collect the product, and the macromolecular modifier can be obtained.

[0018] As a further embodiment of the present invention, the molar ratio of the hydroxyethyl hexahydro-s-triazine to 2,7-dibromopyrene is 1:1-1.5.

[0019] As a further embodiment of the present invention, the catalyst is sodium hydride.

[0020] As a further solution of the present invention, in step S2, the mass fraction of the sodium hydroxide solution is 10-20%.

[0021] In the above technical scheme, hydroxyethyl hexahydro-s-triazine and 2,7-dibromopyrene are first used as polymerization monomer reactants. After continuous substitution reactions, a macromolecular modifier connected by ether bonds is formed. By controlling the molar ratio of the polymerization monomers, the prepared macromolecular modifier can have a branched structure and contain a large number of substituted hydroxyl groups.

[0022] Next, using 1,4-dichlorobutane as a modifier, under irradiation conditions, the halogen chlorine at one end of its structure can undergo an alkylation reaction with the benzene ring in the aramid fiber structure, thereby achieving halogen modification of the aramid fiber and obtaining halogenated aramid fiber. Then, through sodium hydroxide catalysis, it is substituted with the hydroxyl group in the structure of the macromolecular modifier, thereby grafting the macromolecular modifier onto the surface of the aramid fiber to obtain modified aramid fiber.

[0023] A functional aramid fiber UD cloth is prepared by adopting the preparation method.

[0024] (III) Beneficial technical effects

[0025] The invention uses a macromolecular modifier to modify aramid fiber to obtain modified aramid fiber. Firstly, the macromolecular modifier contains a branched structure and contains a large number of ether bonds and hydroxyl groups. The ether bonds can generate hydrogen bonds with epoxy resin molecular chains. The hydroxyl groups can participate in the curing process of epoxy resin glue in the subsequent hot pressing process. The branched structure of the macromolecular modifier can form hydrogen bond connection sites at the interface of the aramid fiber and the glue, and form a hydrogen bond network, thereby greatly improving the affinity between the aramid fiber and the epoxy resin glue, and avoiding the occurrence of warping, bulging and the like in the subsequently prepared UD cloth. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0027] Figure 1 Scanning electron microscope images of aramid fiber and modified aramid fiber. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. Preferred embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0029] Preparation Example 1

[0030] Preparation of modified aramid fiber:

[0031] Step S1: 3 g of aramid fiber was mixed with 100 mL of 1,4-dichlorobutane, and ultrasonicated to form a uniform dispersion. Then, at room temperature, the irradiation dose was controlled to be 500 KGy. 60 The dispersion is irradiated by a Co irradiation source, and after the irradiation is completed, the fiber material is taken out and separated, and then washed and vacuum dried to form a halogenated aramid fiber;

[0032] Step S2, adding 1.2 g of hydroxyethyl hexahydro-s-triazine and N,N-dimethylformamide to a polymerization kettle, starting stirring, and after a uniform reaction solution is formed, adding 2.5 g of 2,7-dibromopyrene and 0.1 g of sodium hydride to the reaction solution, stirring and mixing uniformly, then controlling the heating rate to be 3°C / min, raising the temperature to 120°C, and keeping stirring at this temperature for 18 hours, evaporating to remove the solvent, cooling and discharging, collecting the product, and obtaining a macromolecular modifier;

[0033] Step S3, dispersing 2.5g of halogenated aramid fiber in toluene, and then adding 1.6g of macromolecular modifier and 5mL of 15% sodium hydroxide solution to the formed dispersion. After the addition, controlling the temperature to 100°C, keeping the mixture warm for 9h under continuous stirring, separating the fiber material, and obtaining the modified aramid fiber.

[0034] Figure 1 The scanning electron microscope images of aramid fiber and modified aramid fiber, where (1) is aramid fiber and (2) is modified aramid fiber. It can be seen that the surface of aramid fiber is smooth without obvious special morphology, while the surface of modified aramid fiber has obvious irregular concave-convex morphology, which is caused by coating with macromolecular modifier.

[0035] Example 1

[0036] A method for preparing a functional aramid fiber UD cloth comprises the following steps:

[0037] The first step is to dry the modified aramid fiber, pass through the yarn spreading and pulling device, and then enter the glue tank filled with epoxy resin glue for glue treatment to form glue-containing aramid fiber;

[0038] The second step is to clean the low-density polyethylene film in an ultrasonic instrument and then dry it;

[0039] The third step is to laminate the washed and air-dried low-density polyethylene film with the rubber-containing aramid fiber, and then place it under a temperature of 100°C for drying and curing, and then carry out a pulling and winding process to make a single-layer aramid fiber UD cloth;

[0040] The fourth step is to cut the single-layer aramid fiber UD cloth into uniform specifications, and then stack them in an interlaced manner in the radial / weft direction, and then use a pressing roller for pre-pressing to form a multi-layer aramid fiber UD cloth. Finally, control the hot pressing temperature to 120°C and the pressure to 5MPa, and perform the pressing roller treatment for 5 minutes to obtain the aramid fiber UD cloth.

[0041] The preparation method of the modified aramid fiber is shown in Preparation Example 1, and the same is true for the following.

[0042] Example 2

[0043] A method for preparing a functional aramid fiber UD cloth comprises the following steps:

[0044] The first step is to dry the modified aramid fiber, pass through the yarn spreading and pulling device, and then enter the glue tank filled with epoxy resin glue for glue treatment to form glue-containing aramid fiber;

[0045] The second step is to clean the low-density polyethylene film in an ultrasonic instrument and then dry it;

[0046] The third step is to laminate the washed and air-dried low-density polyethylene film with the rubber-containing aramid fiber, and then place it at a temperature of 110°C for drying and curing, and then carry out a pulling and winding process to make a single-layer aramid fiber UD cloth;

[0047] The fourth step is to cut the single-layer aramid fiber UD cloth into uniform specifications, and then stack them in an interlaced manner in the radial / weft direction, and then use a pressing roller for pre-pressing to form a multi-layer aramid fiber UD cloth. Finally, control the hot pressing temperature to 130°C and the pressure to 5MPa, and perform the pressing roller treatment for 3 minutes to obtain the aramid fiber UD cloth.

[0048] Example 3

[0049] A method for preparing a functional aramid fiber UD cloth comprises the following steps:

[0050] The first step is to dry the modified aramid fiber, pass through the yarn spreading and pulling device, and then enter the glue tank filled with epoxy resin glue for glue treatment to form glue-containing aramid fiber;

[0051] The second step is to clean the low-density polyethylene film in an ultrasonic instrument and then dry it;

[0052] The third step is to laminate the washed and air-dried low-density polyethylene film and the rubber-containing aramid fiber, and then place it under a temperature of 120°C for drying and curing, and then carry out a pulling and winding process to make a single-layer aramid fiber UD cloth;

[0053] The fourth step is to cut the single-layer aramid fiber UD cloth into uniform specifications, and then stack them in an interlaced manner in the radial / weft direction, and then use a pressing roller for pre-pressing to form a multi-layer aramid fiber UD cloth. Finally, control the hot pressing temperature to 150°C and the pressure to 3MPa, and perform the pressing roller treatment for 3 minutes to obtain the aramid fiber UD cloth.

[0054] Comparative Example 1

[0055] A method for preparing a functional aramid fiber UD cloth comprises the following steps:

[0056] The first step is to dry the aramid fiber, pass through the yarn spreading and pulling device, and then enter the glue tank filled with epoxy resin glue for glue treatment to form glue-containing aramid fiber;

[0057] The second step is to clean the low-density polyethylene film in an ultrasonic instrument and then dry it;

[0058] The third step is to laminate the washed and air-dried low-density polyethylene film with the rubber-containing aramid fiber, and then place it at a temperature of 110°C for drying and curing, and then carry out a pulling and winding process to make a single-layer aramid fiber UD cloth;

[0059] The fourth step is to cut the single-layer aramid fiber UD cloth into uniform specifications, and then stack them in an interlaced manner in the radial / weft direction, and then use a pressing roller for pre-pressing to form a multi-layer aramid fiber UD cloth. Finally, control the hot pressing temperature to 130°C and the pressure to 5MPa, and perform the pressing roller treatment for 3 minutes to obtain the aramid fiber UD cloth.

[0060] Test Case

[0061] The aramid fiber UD cloth in the embodiment and the comparative example was cut into 10 cm×10 cm cloth samples, placed in a temperature environment of 50° C. for one month, and then taken out to observe whether there were warping, bulging, etc. to determine the stability of the cloth samples. The test results are recorded in the following table:

[0062] Table 1 - Test results

[0063] Example 1 Example 2 Example 3 Comparative Example 1 Phenomenon No obvious phenomenon No obvious phenomenon No obvious phenomenon Warping and bulging are serious

[0064] According to the test results, the UD cloth made of the modified aramid fiber in Preparation Example 1 of the present invention is significantly more stable, indicating that the fiber has a better affinity with the epoxy resin glue, and the service life of the aramid fiber UD cloth can be extended.

[0065] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

[0066] Based on the ideal embodiment of the present invention, through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A method for preparing a functional aramid fiber UD cloth, characterized in that: The following steps are involved: The first step is to dry the modified aramid fiber, pass through the yarn spreading and pulling device, and then enter the glue tank filled with epoxy resin glue for glue treatment to form glue-containing aramid fiber; The second step is to clean the low-density polyethylene film in an ultrasonic instrument and then dry it; The third step is to laminate the washed and air-dried low-density polyethylene film with the rubber-containing aramid fiber, and then place it under a temperature of 100-120°C for drying and curing, and then carry out a pulling and winding process to make a single-layer aramid fiber UD cloth; The fourth step is to cut the single-layer aramid fiber UD cloth into uniform specifications, and then alternately stack them in the radial / weft direction, and then use a pressing roller for pre-pressing to form a multi-layer aramid fiber UD cloth. Finally, control the hot pressing temperature to 120-150°C and the pressure to 3-5MPa, and perform the pressing roller treatment for 3-5min to obtain the aramid fiber UD cloth.

2. The method for preparing a functional aramid fiber UD cloth according to claim 1, characterized in that: In the first step, the specific preparation method of the modified aramid fiber comprises the following steps: Step S1, mixing aramid fiber with 1,4-dichlorobutane, ultrasonicating to form a uniform dispersion, and then using 60 The dispersion is irradiated by a Co irradiation source, and after the irradiation is completed, the fiber material is taken out and separated, and then washed and vacuum dried to form a halogenated aramid fiber; Step S2, dispersing the halogenated aramid fiber in toluene, and then adding a macromolecular modifier and a sodium hydroxide solution to the formed dispersion. After the addition, the temperature is controlled to 80-100° C., and the mixture is kept warm for 8-12 hours under continuous stirring. The fiber material is separated to obtain the modified aramid fiber.

3. The method for preparing a functional aramid fiber UD cloth according to claim 2, characterized in that: In step S1, the irradiation dose during the irradiation treatment is 200 to 1000 KGy.

4. The method for preparing a functional aramid fiber UD cloth according to claim 2, characterized in that: In step S2, the preparation method of the macromolecular modifier is: using hydroxyethyl hexahydro-s-triazine and 2,7-dibromopyrene as polymerization monomers, using N,N-dimethylformamide as a medium, adding a catalyst, and performing continuous substitution to obtain the macromolecular modifier.

5. The method for preparing a functional aramid fiber UD cloth according to claim 4, characterized in that: The molar ratio of the hydroxyethyl hexahydro-s-triazine to 2,7-dibromopyrene is 1:1-1.

5.

6. The method for preparing a functional aramid fiber UD cloth according to claim 4, characterized in that: The catalyst is sodium hydride.

7. The method for preparing a functional aramid fiber UD cloth according to claim 2, characterized in that: In step S2, the mass fraction of the sodium hydroxide solution is 10-20%.

8. A functional aramid fiber UD cloth, characterized in that: The method is prepared according to claim 1-8.

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