An ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone composite material, a preparation method and application thereof

Abstract

The application discloses an ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone composite material and a preparation method and application thereof, and belongs to the technical field of high-performance fiber reinforced resin matrix composite materials.The application realizes the synergy of surface activation and thermal protection of the ultra-high molecular weight polyethylene fiber by means of a synergistic modification strategy of photo-initiated grafting and elastomer coating and a fast hot-pressing composite process, and significantly improves the interfacial bonding capacity with a polyether ether ketone matrix on the premise of maintaining the original mechanical properties of the ultra-high molecular weight polyethylene fiber.

Description

Technical Field

[0001] This invention relates to the field of high-performance fiber-reinforced resin-based composite materials, and in particular to an ultra-high molecular weight polyethylene fiber-reinforced polyetheretherketone composite material, its preparation method, and its application. Background Technology

[0002] Ultra-high molecular weight polyethylene (UHMWPE) fiber is one of the fibers with the highest specific strength and specific modulus in the world today, with a density of only 0.97 g / cm³. 3 With a strength of over 30 cN / dtex, it has excellent impact resistance and energy absorption capacity, and has broad application prospects in fields such as bulletproof protection, aerospace, and marine engineering.

[0003] Polyetheretherketone (PEEK) is a semi-crystalline aromatic thermoplastic engineering plastic with a glass transition temperature of approximately 143°C and a melting point of approximately 343°C. It possesses excellent heat resistance, chemical corrosion resistance, and mechanical strength, making it an ideal matrix material for high-performance thermoplastic composites.

[0004] However, there are two major technical bottlenecks in combining UHMWPE fibers with PEEK resin: First, there is the challenge of interfacial bonding. The surface of UHMWPE fibers is highly chemically inert and lacks active functional groups, resulting in extremely poor wettability and adhesion to PEEK resin. This leads to low interfacial shear strength in the composite material and makes it prone to interfacial debonding failure.

[0005] Second, there is the contradiction of heat damage. The processing temperature of PEEK resin (360-400℃) is much higher than the heat distortion temperature of UHMWPE fiber (about 80℃). In conventional melt impregnation process, the high temperature of PEEK melt will cause thermal degradation and oxidative degradation of UHMWPE fiber, resulting in serious deterioration of fiber mechanical properties, and the strength retention rate is usually less than 60%.

[0006] The existing technologies mainly adopt the following improvement schemes: (1) Plasma treatment: improves the surface activity of fibers, but the treatment effect is unstable, the timeliness is poor, and the equipment investment is high; (2) Chemical plating or sizing treatment: introduces a third phase interface layer, but increases the complexity of the process, and some treatment agents are not compatible with PEEK; (3) Reduce the processing temperature: use solvent method or supercritical fluid assisted impregnation, but the solvent residue problem is prominent, the environmental protection is poor, and the efficiency is low.

[0007] Therefore, developing a method for preparing UHMWPE / PEEK composite materials that can effectively activate the surface of UHMWPE fibers while avoiding high-temperature thermal damage has significant engineering application value. Summary of the Invention

[0008] The purpose of this invention is to provide an ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone composite material, its preparation method and application, in order to solve the key technical problems of poor interfacial bonding between ultra-high molecular weight polyethylene fiber and polyether ether ketone resin and high-temperature thermal damage.

[0009] To achieve the above objectives, the present invention provides a method for preparing ultra-high molecular weight polyethylene fiber-reinforced polyetheretherketone composite materials, comprising the following steps: S1. The ultra-high molecular weight polyethylene fiber cloth is soaked in a photoinitiator solution, filtered dry, and then grafted polymerized in a polar monomer solution to obtain grafted modified ultra-high molecular weight polyethylene fiber cloth. S2. The grafted and modified ultra-high molecular weight polyethylene fiber is impregnated in a heat-resistant elastomer solution to obtain a surface-modified ultra-high molecular weight polyethylene fiber cloth. S3. Heat and cure the surface-modified ultra-high molecular weight polyethylene fiber cloth to obtain a single-layer surface-modified ultra-high molecular weight polyethylene fiber cloth composite layup. S4. Melt polyether ether ketone and sandwich it between two layers of surface-modified ultra-high molecular weight polyethylene fiber cloth composite layup, then hot-press composite to obtain ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone composite material.

[0010] Preferably, in S1, the photoinitiator includes benzophenone or its derivatives, the solvent of the photoinitiator solution is acetone, the concentration of the photoinitiator solution is 1-10 wt%, the soaking time is 30-120 min, and the soaking temperature is 18-25℃.

[0011] Preferably, in S1, the polar monomer includes any one of acrylic acid, methacrylic acid, or hydroxyethyl acrylate, the solvent of the polar monomer solution is ethanol or an ethanol-water mixture, and the concentration of the polar monomer solution is 30-80 wt%.

[0012] Preferably, in S1, the mass-to-volume ratio of ultra-high molecular weight polyethylene fiber cloth, photoinitiator solution, and polar monomer solution is 4.6 g: 600 mL: 600 mL, and the areal density of the ultra-high molecular weight polyethylene fiber cloth is 200 g / m³. 2 The graft polymerization reaction time is 30-90 min, and the temperature is 40-80℃. The graft polymerization reaction is carried out under ultraviolet light irradiation with a wavelength of 300-400 nm and an irradiance of 10-50 mW / cm². 2 .

[0013] Preferably, in S2, the heat-resistant elastomer includes liquid butyl rubber or halogenated butyl rubber, the solvent of the heat-resistant elastomer solution is xylene or toluene, the concentration of the heat-resistant elastomer solution is 10-30wt%, the impregnation temperature is 60-80℃, the impregnation time is 60-120min, and the volume-to-mass ratio of the heat-resistant elastomer solution to the ultra-high molecular weight polyethylene fiber cloth is 600mL:4.6g.

[0014] Preferably, in step S3, the heat curing temperature is 60-80℃, and the heat curing time is 15-30 minutes; the heat curing is carried out under ultraviolet light irradiation, with a wavelength of 300-400 nm and an irradiance of 10-50 mW / cm². 2 .

[0015] Preferably, in S4, the thickness of polyetheretherketone is 0.1-0.5 mm, the melting temperature is 340-380℃, the melting heating rate is 3-7℃ / min, and the melting time is 30-60 min; the mass ratio of polyetheretherketone to ultra-high molecular weight polyethylene fiber cloth is 4.6:35.

[0016] Preferably, in S4, the pressure of hot pressing is 2-3 MPa, the holding time of hot pressing is 0.5-1 min, and the hot pressing rate is 10 mm / s.

[0017] The present invention also provides an ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone composite material, which is prepared by the above preparation method; the composite material has a sandwich layered structure, with polyether ether ketone resin layers and modified ultra-high molecular weight polyethylene fiber cloth layers arranged alternately; the surface of the modified ultra-high molecular weight polyethylene fiber cloth layer has a dual modified structure of "grafted chain segment-elastomer coating layer".

[0018] The present invention also provides an application of ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone composite material, which is applied to impact-resistant protective equipment.

[0019] The technical principle of this invention is as follows: Under ultraviolet light, the photoinitiator extracts hydrogen from the tertiary carbon atoms on the surface of ultra-high molecular weight polyethylene (UHMWPE) fibers, forming surface free radicals that initiate the graft polymerization of polar monomers. This introduces polar groups such as carboxyl groups onto the fiber surface, significantly improving the interfacial compatibility with PEEK. The heat-resistant elastomer has extremely low gas permeability and excellent thermal stability, forming a continuous coating layer on the surface of the UHMWPE fibers. This effectively blocks heat transfer from the high-temperature PEEK melt, protecting the UHMWPE fibers from heat damage. By controlling the PEEK to be in a highly viscoelastic rather than fluid state (340-380℃) and applying rapid pressure (2-3 MPa), the high-temperature contact time is minimized (<2 min) while ensuring the resin fully wets the fibers, thus avoiding fiber thermal degradation. Utilizing the residual double bonds in the grafted segments or the unsaturated bonds in the elastomer, further cross-linking occurs under ultraviolet light, forming a stable interfacial transition layer that enhances interfacial bonding strength and environmental resistance.

[0020] Therefore, the present invention, employing the above-mentioned ultra-high molecular weight polyethylene fiber reinforced polyetheretherketone composite material, its preparation method, and its application, has the following beneficial effects: (1) The present invention introduces polar functional groups on the surface of ultra-high molecular weight polyethylene fiber by photo-initiated grafting, which form chemical bonds and hydrogen bonds with the polyether ether ketone matrix, significantly improving the interfacial bonding strength.

[0021] (2) In this invention, the butyl rubber elastomer coating layer forms an effective thermal protection barrier on the surface of ultra-high molecular weight polyethylene fiber. Combined with the short-time rapid hot pressing process (pressing time <1min), the strength retention rate of ultra-high molecular weight polyethylene fiber is as high as 93%.

[0022] (3) The process route of the present invention does not require expensive equipment such as plasma or electron beam. Conventional impregnation and hot pressing equipment can be used to achieve large-scale production, and all solvents used can be recycled, which meets the requirements of green manufacturing.

[0023] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0024] The technical solution of the present invention will be further described below through embodiments.

[0025] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0026] In this invention, unless otherwise specified, the test materials and instruments are all conventional test materials in the field and can be purchased through commercial channels.

[0027] Example 1 A method for preparing an ultra-high molecular weight polyethylene fiber-reinforced polyetheretherketone composite material includes the following steps: S1. Use 1000D UHMWPE plain weave fiber fabric (area density 200g / m²) 2 4.6g was immersed in 600mL of 5wt% benzophenone in acetone solution at 25℃ in the dark to allow benzophenone to fully penetrate and adsorb onto the fiber surface and amorphous areas. After 60 minutes, it was removed and air-dried at room temperature. Then, it was immersed in 600mL of 70wt% acrylic acid ethanol solution and placed in a UV curing chamber for UV irradiation at 70℃ (365nm, 30mW / cm). 2 The grafting polymerization reaction was carried out for 60 min, and the product was washed three times with ethanol and dried under vacuum at 60℃ for 2 h to obtain grafted modified ultra-high molecular weight polyethylene fiber cloth. S2. The grafted and modified ultra-high molecular weight polyethylene fiber cloth is immersed in 600 mL of 20 wt% liquid butyl rubber xylene solution, immersed at 70 °C for 90 min, then removed and air-dried at room temperature to obtain surface-modified ultra-high molecular weight polyethylene fiber cloth. S3. Arrange surface-modified ultra-high molecular weight polyethylene fibers in a UV curing chamber and irradiate with UV light (365nm, 20mW / cm²) at 70℃. 2 After curing for 20 minutes, a single-layer surface-modified ultra-high molecular weight polyethylene fiber cloth composite layup is obtained. S4. Using 35g of Victrex 150G PEEK film (0.3mm thickness), cover it on an 80-mesh brass mesh (0.08mm wire diameter), place it in an oven and heat it to 360℃ at a rate of 5℃ / min, hold it at that temperature for 30min to make the PEEK in a highly viscoelastic molten state; quickly transfer the molten PEEK film to a press, clamp it between two layers of surface-modified UHMWPE fiber cloth, apply pressure rapidly at 2.5MPa and a rate of 10mm / s, hold the pressure for 1min to obtain ultra-high molecular weight polyethylene fiber reinforced polyetheretherketone composite material.

[0028] Example 2 This embodiment operates the same as Embodiment 1, except that the thickness of the PEEK film in S4 is 0.2 mm and the melting temperature is 380°C.

[0029] Example 3 This embodiment operates in the same way as Embodiment 1, except that: in S2, the heat-resistant elastomer is chlorinated butyl rubber, the concentration of the chlorinated butyl rubber solution is 15wt%, and the impregnation temperature is 75℃.

[0030] Comparative Example 1 The operation of this comparative example is the same as that of Example 1, except that S1, S2, and S3 are not performed. In S4, the polyether ether ketone is melted and sandwiched between two layers of ultra-high molecular weight polyethylene fiber cloth (without surface modification) for hot pressing composite.

[0031] Comparative Example 2 This comparative example operates in the same way as Example 1, except that S2 is not performed.

[0032] The ultra-high molecular weight polyethylene fiber-reinforced polyetheretherketone (UHMWPE) composite material prepared in Example 1 was stacked in three layers along the 0° / 90° / 0° direction and then hot-pressed at 2 MPa and 360°C for 10 min to obtain a laminate. A drop hammer impact test was performed according to ASTM D7136; at an impact energy of 100 J, the laminate was not penetrated, and the back-convex deformation was <25 mm. A short beam shear test was performed according to ASTM D2344; the interlaminar shear strength was 28.5 MPa; and the UHMWPE fiber strength retention rate was 93%. This indicates that the material possesses excellent impact resistance, interfacial bonding strength, and fiber mechanical property retention.

[0033] The ultra-high molecular weight polyethylene fiber-reinforced polyetheretherketone composite material prepared in Example 2 was stacked in five layers with aligned warp and weft patterns. The calculated areal density was 18 kg / m³. 2 (Total mass of composite material / paved area); ballistic tests were conducted according to NIJ Level III standards, and it can stop 7.62×51mm NATO rounds with a V50 value of 650m / s.

[0034] The interfacial bonding stability of the ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone composite material prepared in Example 3 was characterized using the short beam method. According to ASTM D2344 / GB / T 1450.1, after aging for 1000 hours at a temperature of 85℃ and a relative humidity of 85%, the interlaminar shear strength retention rate was calculated to be 87%, indicating that the composite material has stable interfacial bonding and excellent resistance to humid heat aging.

[0035] In Comparative Example 1, the ultra-high molecular weight polyethylene fiber reinforced polyetheretherketone composite material was unable to be molded into a complete board because PEEK could not effectively impregnate the ultra-high molecular weight polyethylene fiber.

[0036] In Comparative Example 2, the UHMWPE fiber-reinforced polyetheretherketone (PEEK) composite material exhibited severe thermal shrinkage and brittleness. The composite material was stacked in three layers along the 0° / 90° / 0° direction and hot-pressed at 2 MPa and 360°C for 10 min to obtain a laminate. Short beam shear tests according to ASTM D2344 showed a fiber strength retention rate of only 45% and an interlaminar shear strength of 12 MPa.

[0037] The characterization tests on the ultra-high molecular weight polyethylene fiber-reinforced polyetheretherketone (PEEK) composites of Examples 1-3 and Comparative Examples 1-2 show that the present invention introduces polar functional groups on the fiber surface through photo-initiated grafting, forming chemical bonds and hydrogen bonds with the PEEK matrix, which significantly improves the interfacial bonding strength. Example 1 shows that the interlaminar shear strength reaches 28.5 MPa, which is 1.3 times higher than the unmodified system (Comparative Example 1 cannot be molded). The butyl rubber elastomer coating layer forms an effective thermal protection barrier on the fiber surface. Combined with the short-time rapid hot pressing process (holding time <2 min), the strength retention rate of the ultra-high molecular weight polyethylene fiber is as high as 93% (Example 1), while the fiber strength retention rate of the uncoated system in Comparative Example 2 is only 45%, which fully verifies the effectiveness of the thermal protection strategy. The composite material of Example 2, after being stacked in 5 layers, can meet the NIJ Level III ballistic protection standard, indicating that it has excellent impact resistance.

[0038] Therefore, this invention adopts the above-mentioned ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone composite material, its preparation method and application. Through the synergistic modification strategy of photo-initiated grafting and elastomer coating, combined with rapid hot-pressing composite process, the synergistic effect of UHMWPE fiber surface activation and thermal protection is achieved. While maintaining the original mechanical properties of UHMWPE fiber, the interfacial bonding ability with PEEK matrix is ​​significantly improved.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing an ultra-high molecular weight polyethylene fiber-reinforced polyetheretherketone composite material, characterized in that: Includes the following steps: S1. The ultra-high molecular weight polyethylene fiber cloth is soaked in a photoinitiator solution, filtered dry, and then grafted polymerized in a polar monomer solution to obtain grafted modified ultra-high molecular weight polyethylene fiber cloth. S2. The grafted and modified ultra-high molecular weight polyethylene fiber is impregnated in a heat-resistant elastomer solution to obtain a surface-modified ultra-high molecular weight polyethylene fiber cloth. S3. Heat and cure the surface-modified ultra-high molecular weight polyethylene fiber cloth to obtain a single-layer surface-modified ultra-high molecular weight polyethylene fiber cloth composite layup. S4. Melt polyether ether ketone and sandwich it between two layers of surface-modified ultra-high molecular weight polyethylene fiber cloth composite layup, then hot-press composite to obtain ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone composite material.

2. The method for preparing an ultra-high molecular weight polyethylene fiber reinforced polyetheretherketone composite material according to claim 1, characterized in that: In S1, the photoinitiator includes benzophenone or its derivatives, the solvent of the photoinitiator solution is acetone, the concentration of the photoinitiator solution is 1-10wt%, the soaking time is 30-120min, and the soaking temperature is 18-25℃.

3. The method for preparing an ultra-high molecular weight polyethylene fiber reinforced polyetheretherketone composite material according to claim 1, characterized in that: In S1, the polar monomer includes any one of acrylic acid, methacrylic acid, or hydroxyethyl acrylate, and the solvent of the polar monomer solution is ethanol or an ethanol-water mixture, with a concentration of 30-80 wt%.

4. The method for preparing an ultra-high molecular weight polyethylene fiber reinforced polyetheretherketone composite material according to claim 1, characterized in that: In S1, the mass-to-volume ratio of ultra-high molecular weight polyethylene fiber cloth, photoinitiator solution, and polar monomer solution is 4.6 g: 600 mL: 600 mL, and the areal density of the ultra-high molecular weight polyethylene fiber cloth is 200 g / m³. 2 The graft polymerization reaction time is 30-90 min, and the temperature is 40-80℃. The graft polymerization reaction is carried out under ultraviolet light irradiation with a wavelength of 300-400 nm and an irradiance of 10-50 mW / cm². 2 .

5. The method for preparing an ultra-high molecular weight polyethylene fiber reinforced polyetheretherketone composite material according to claim 1, characterized in that: In S2, the heat-resistant elastomer includes liquid butyl rubber or halogenated butyl rubber. The solvent of the heat-resistant elastomer solution is xylene or toluene. The concentration of the heat-resistant elastomer solution is 10-30 wt%. The impregnation temperature is 60-80℃. The impregnation time is 60-120 min. The volume-to-mass ratio of the heat-resistant elastomer solution to the ultra-high molecular weight polyethylene fiber cloth is 600 mL: 4.6 g.

6. The method for preparing an ultra-high molecular weight polyethylene fiber reinforced polyetheretherketone composite material according to claim 1, characterized in that: In S3, the heat curing temperature is 60-80℃, and the heat curing time is 15-30 minutes. Heat curing is carried out under ultraviolet light irradiation with a wavelength of 300-400 nm and an irradiance of 10-50 mW / cm². 2 .

7. The method for preparing an ultra-high molecular weight polyethylene fiber reinforced polyetheretherketone composite material according to claim 1, characterized in that: In S4, the thickness of polyetheretherketone is 0.1-0.5 mm, the melting temperature is 340-380℃, the melting heating rate is 3-7℃ / min, and the melting time is 30-60 min; the mass ratio of polyetheretherketone to ultra-high molecular weight polyethylene fiber cloth is 4.6:

35.

8. The method for preparing an ultra-high molecular weight polyethylene fiber reinforced polyetheretherketone composite material according to claim 1, characterized in that: In S4, the pressure for hot-pressing is 2-3 MPa, the holding time for hot-pressing is 0.5-1 min, and the hot-pressing rate is 10 mm / s.

9. A high molecular weight polyethylene fiber reinforced polyetheretherketone composite material, characterized in that: The composite material was prepared using the method described in any one of claims 1-8 for ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone.

10. An application of an ultra-high molecular weight polyethylene fiber-reinforced polyetheretherketone composite material, characterized in that: The ultra-high molecular weight polyethylene fiber reinforced polyether ether ketone composite material prepared by the preparation method of any one of claims 1-8 is applied to impact-resistant protective equipment.