Wear-resistant and high-strength polyamide material

Abstract

The invention discloses a wear-resistant and high-strength polyamide material. The wear-resistant and high-strength polyamide material is prepared from the following raw materials in parts by mass: 60 to 70 parts of polyhexamethylene adipamide, 45 to 48 parts of polyamide 6, 12 to 15 parts of polylaurolactam, 0.3 to 0.42 part of phenyl sodium hypophosphite and 2 to 3.2 parts of organosilane modified montmorillonite. And 4.2-5.6 parts by mass of carbon nanotubes, so that the polyamide disclosed by the invention has high wear resistance and high strength performance.

Description

Technical Field

[0001] This application relates to engineering plastics, and in particular to a wear-resistant and high-strength polyamide material. Background Art

[0002] As an important engineering plastic, polyamide materials play a crucial role in modern industry. They are widely used in fields such as automobiles, electronic and electrical appliances, and machinery manufacturing, providing reliable guarantees for the structural strength and durability of products. With the development of technology, the demand for polyamide materials is increasing day by day, especially in high-performance and high-wear-resistant application scenarios, which pose higher requirements for their performance.

[0003] In the prior art, in order to improve the strength and wear resistance of polyamide materials, various methods are usually adopted. For example, by adding inorganic fillers, fibers or nano-materials to enhance the mechanical properties of the materials. However, the existing polyamide materials still have deficiencies in the balance between high strength and high wear resistance.

[0004] Especially under complex working conditions, how to simultaneously improve the synergy of material strength and wear resistance has become an urgent problem to be solved. The single modification methods in the prior art often fail to meet this requirement, resulting in defects such as insufficient tensile strength or poor wear resistance of the materials in practical applications. Therefore, there is an urgent need to develop a new type of polyamide material that can effectively solve the above problems. Summary of the Invention

[0005] To simultaneously provide the wear resistance and mechanical strength of polyamide products, a wear-resistant and high-strength polyamide material is provided.

[0006] The above-mentioned invention object of the present invention is achieved through the following technical solutions: A wear-resistant and high-strength polyamide material, comprising the following raw materials in parts by mass: 60 - 70 parts by mass of polyhexamethylene adipamide, 45 - 48 parts by mass of polyamide 6, 12 - 15 parts by mass of polylauryl lactam, 0.3 - 0.42 parts by mass of sodium phenylphosphinate, 2 - 3.2 parts by mass of organosilane-modified montmorillonite, 4.2 - 5.6 parts by mass of carbon nanotubes.

[0007] By adopting the technical solution, sodium phenylphosphinate and organosilane-modified montmorillonite are added in this application. Sodium phenylphosphinate can induce the formation of the rigid α-crystalline form of polyamide, and organosilane-modified montmorillonite can induce the formation of the tough network γ-crystalline form. Thus, the two crystalline forms are blended to form a bicontinuous phase structure, synchronously improving the tensile strength and impact strength of polyamide; In addition, carbon nanotubes are added to this application. Carbon nanotubes can significantly improve the wear resistance of polyamide materials. At the same time, in this application, the carbon nanotubes also guide the crystal growth along the orientation of the carbon nanotubes, adjust the orientation arrangement along the shear direction during the melt processing, provide a directional template for grain growth, optimize the crystal form distribution, and further improve the strength performance of the polyamide material; Thus, the polyamide of this application has high wear resistance and high strength performance.

[0008] Optionally: The organosilane used for the organosilane-modified montmorillonite is γ-glycidoxypropyltrimethoxysilane.

[0009] By adopting the above technical solution, γ-glycidoxypropyltrimethoxysilane can inhibit the residual water molecules between the layers of the organosilane-modified montmorillonite, reduce the melt flow rate fluctuation and the mixing of small air holes in the melt during the preparation of the polyamide material, which affects the distribution of carbon nanotubes and crystal forms, and thus optimize the wear resistance and strength of the polyamide material.

[0010] Optionally: It also includes 0.8 - 1.1 parts by mass of p-phenylenediamine.

[0011] By adopting the above technical solution, during the production and processing, p-phenylenediamine can react with the oxidized end groups of the polyamide to form cross-linked chains. The formed cross-links can reversibly break / recombine at 80 ± 10 °C, thereby absorbing the heat generated during the friction process of the polyamide material, reducing the heat softening of the polyamide material during the friction process, and further improving the wear resistance of the polyamide material.

[0012] Optionally: The particle size of the organosilane-modified montmorillonite is 300 - 400 nm.

[0013] By adopting the above technical solution, the obtained polyamide material of this application has better strength and wear resistance.

[0014] Optionally: It also includes 0.5 - 0.73 parts by mass of 1-pyrenebutyric acid.

[0015] By adopting the above technical solution, the added 1-pyrenebutyric acid serves as an interfacial linker. Its pyrene group enhances the interfacial bonding with the carbon nanotubes through π-π stacking, and its carboxylic acid group is covalently bonded to the nylon terminal amine group, thereby improving the dispersion uniformity of the carbon nanotubes and enhancing the wear resistance and strength of the polyamide material.

[0016] Optionally: The aspect ratio of the carbon nanotubes is (150:1) - (200:1).

[0017] By adopting the above technical solution, the obtained polyamide material of this application has better strength and wear resistance.

[0018] Optionally, it further includes 8-12 parts by mass of calcium carbonate microspheres, the calcium carbonate microspheres having a particle size of 2-4 μm and a porosity of 43-57%.

[0019] By adopting the above technical solution, the calcium carbonate microspheres with high porosity, whose structure is like that of cancellous bone, can be embedded in the polyamide material to strengthen the structure and reduce the sliding between friction surface layers during friction, thereby improving the strength and wear resistance of the polyamide material of the present application.

[0020] Optionally, it further includes 1-1.4 parts by mass of triglycerol borate.

[0021] By adopting the above technical solution, triglycerol borate can undergo a polycondensation reaction with the residual terminal amino groups and terminal carboxyl groups of the polyamide to form borate bonds, and these bonds undergo reversible dissociation at a processing temperature of 120±10°C; The reversibly dissociating crosslinking points are concentrated in the amorphous region and do not hinder the regular arrangement of PA chain segments, so the polyamide material has a high crystallinity and good strength; In addition, the reversible crosslinking that occurs endows the material with self-healing ability. When the temperature rises during processing or friction, the crosslinking bonds dissociate to release internal stress, avoiding brittle fracture, and the network reconstructs after cooling, inhibiting crack propagation, so the wear resistance of the polyamide material is further improved.

[0022] In summary, the present application has at least the following beneficial effects: Through crystal form induction and coordination among components, the polyamide of the present application has high wear resistance and high strength performance. Specific Embodiments

[0023] Raw Materials Sodium montmorillonite, a product of Zhejiang Fenghong New Materials.

[0024] γ-Glycidyletheroxypropyltrimethoxysilane and propyltrimethoxysilane are commercially available products from Nanjing Shuguang Silane.

[0025] CaCl2 is a commercially available analytical pure product.

[0026] CTAB, cetyltrimethylammonium bromide, is a commercially available product from Sigma-Aldrich.

[0027] Polyvinyl alcohol with a molecular weight of 40,000 is a commercially available product.

[0028] Polyhexamethylene adipamide is from DuPont TM 101.

[0029] Polyamide 6 is from BASF B3 Polylauryl lactam is from Arkema PA12 Sodium phenylphosphinate is a product of Aladdin Reagent, CAS 101-89-3, with a purity of ≥98%.

[0030] Carbon nanotubes with a diameter of 1 nm are customized products of Zhongke Naxin. The length-diameter ratio can be found in the specific examples and comparative examples.

[0031] 1-Pyrenebutyric acid is a product of Sigma-Aldrich, CAS 103826-26-8, with a purity of ≥97%.

[0032] p-Phenylenediamine is a product of Alfa Aesar, CAS 106-50-3, with a purity of ≥99%.

[0033] Triglycerol borate is a product of BOC Sciences, CAS 17796-04-2, with a purity of ≥95%.

[0034] Preparation Example 1 An organosilane-modified montmorillonite, and its preparation method is as follows: Disperse 1 kg of sodium-based montmorillonite with a particle size D80 = 350 nm in 20 kg of deionized water, and treat it with ultrasonic at 40 kHz for 30 min; add 0.15 kg of γ-glycidoxypropyltrimethoxysilane, and stir and react at 80 °C for 6 h; Centrifuge and wash until the pH is neutral, vacuum dry at 80 °C for 12 h, and sieve to select the material with a particle size of 350 nm to obtain the organosilane-modified montmorillonite.

[0035] Preparation Example 2 An organosilane-modified montmorillonite, which is different from Preparation Example 1 in that propyltrimethoxysilane is used to replace γ-glycidoxypropyltrimethoxysilane in an equimolar amount.

[0036] Preparation Example 3 An organosilane-modified montmorillonite, and its preparation method is as follows: Disperse 1 kg of sodium-based montmorillonite with a particle size D80 = 100 nm in 20 kg of deionized water, and treat it with ultrasonic at 40 kHz for 30 min; Add 0.15 kg of γ-glycidoxypropyltrimethoxysilane, and stir and react at 80 °C for 6 h; Centrifuge and wash until the pH is neutral, vacuum dry at 80 °C for 12 h, and sieve to select the material with a particle size of 100 nm to obtain the organosilane-modified montmorillonite.

[0037] Preparation Example 4 An organosilane-modified montmorillonite, and its preparation method is as follows: Disperse 1 kg of sodium-based montmorillonite with a particle size D80 = 300 nm in 20 kg of deionized water, and treat it with ultrasonic at 40 kHz for 30 min; Add 0.15 kg of γ-glycidoxypropyltrimethoxysilane and stir and react at 80 °C for 6 h; Centrifuge and wash until the pH is neutral, vacuum dry at 80 °C for 12 h, and sieve to select materials with a size of 300 nm to obtain organosilane-modified montmorillonite.

[0038] Preparation Example 5 An organosilane-modified montmorillonite, and its preparation method is as follows: Disperse 1 kg of sodium-based montmorillonite with a particle size D80 = 400 nm in 20 kg of deionized water and treat it with ultrasound at 40 kHz for 30 min; Add 0.15 kg of γ-glycidoxypropyltrimethoxysilane and stir and react at 80 °C for 6 h; Centrifuge and wash until the pH is neutral, vacuum dry at 80 °C for 12 h, and sieve to select materials with a size of 400 nm to obtain organosilane-modified montmorillonite.

[0039] Preparation Example 6 An organosilane-modified montmorillonite, and its preparation method is as follows: Disperse 1 kg of sodium-based montmorillonite with a particle size D80 = 600 nm in 20 kg of deionized water, treat it with ultrasound at 40 kHz for 30 min; add 0.15 kg of γ-glycidoxypropyltrimethoxysilane and stir and react at 80 °C for 6 h; Centrifuge and wash until the pH is neutral, vacuum dry at 80 °C for 12 h, and sieve to select materials with a size of 600 nm to obtain organosilane-modified montmorillonite.

[0040] Preparation Example 7 Calcium carbonate microspheres with a particle size of 3 ± 1 μm and a porosity of 50 ± 3%.

[0041] The preparation method is as follows: Using CaCl2, CTAB, polyvinyl alcohol, and deionized water as raw materials, prepare a mixed solution. The component ratios in the mixed solution are 15 wt% of CaCl2, 5 wt% of polyvinyl alcohol, 0.5 wt% of CTAB, and 79.5% of water; Quickly freeze the mixed solution at -60 °C and then vacuum freeze-dry to obtain a composite skeleton; Calcine the composite skeleton at 400 °C for 2 h and then crush it to a particle size of 3 ± 1 μm to obtain calcium carbonate microspheres.

[0042] Example 1 A wear-resistant and high-strength polyamide material, which comprises the following raw materials: 65 kg of polyhexamethylene adipamide, 46.5 kg of polyamide 6, 14 kg of polylaurolactam, 0.36 kg of sodium phenylphosphinate, 2.6 kg of organosilane-modified montmorillonite, and 5 kg of carbon nanotubes.

[0043] The organosilane-modified montmorillonite was prepared as Preparation Example 1.

[0044] The aspect ratio of the carbon nanotubes was 180:1 and the diameter was 1 nm.

[0045] The preparation method is as follows: Polyhexamethylene adipamide, polyamide 6, and polylauryl lactam were premixed evenly in a high-speed mixer and then dried in a vacuum drying oven until the water content was <0.02% to obtain an organic base material; Extrusion granulation was carried out using a twin-screw extruder. The L / D of the twin-screw extruder was 40, the screw speed was 300 rpm, and the twin-screw extruder was sequentially divided into zones 1 to 5 and the head along the material extrusion direction. The temperature of zone 1 was controlled at 235°C, the temperature of zone 2 was controlled at 245°C, the temperature of zone 3 was controlled at 255°C, the temperature of zone 4 was controlled at 255°C, the temperature of zone 5 was controlled at 250°C, and the temperature of the head was 240°C; The organic base material was fed from the main feeding port, sodium phenylphosphinate and the organosilane-modified montmorillonite were fed from the side feeding port of zone 3, and the carbon nanotubes were fed from the side feeding port of zone 4; After melt extrusion granulation, a wear-resistant and high-strength polyamide material was obtained.

[0046] Comparative Example 1 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that the raw materials do not contain sodium phenylphosphinate and organosilane-modified montmorillonite.

[0047] Comparative Example 2 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that the raw materials do not contain sodium phenylphosphinate.

[0048] Comparative Example 3 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that the raw materials contain organosilane-modified montmorillonite.

[0049] Comparative Example 4 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that montmorillonite with a particle size of 350 nm in the raw materials is used to replace the organosilane-modified montmorillonite in equal mass.

[0050] Comparative Example 5 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that the raw materials do not include carbon nanotubes.

[0051] Example 2 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that the organosilane-modified montmorillonite in the raw materials was prepared as Preparation Example 3 and the particle size was 100 nm.

[0052] Example 3 A wear-resistant and high-strength polyamide material, which is different from that of Example 1 in that the organosilane-modified montmorillonite in the raw materials is prepared in Preparation Example 4 and has a particle size of 300 nm.

[0053] Example 4 A wear-resistant and high-strength polyamide material, which is different from that of Example 1 in that the organosilane-modified montmorillonite in the raw materials is prepared in Preparation Example 5 and has a particle size of 400 nm.

[0054] Example 5 A wear-resistant and high-strength polyamide material, which is different from that of Example 1 in that the organosilane-modified montmorillonite in the raw materials is prepared in Preparation Example 6 and has a particle size of 600 nm.

[0055] Example 6 A wear-resistant and high-strength polyamide material, which is different from that of Example 1 in that the aspect ratio of the carbon nanotubes in the raw materials is 100:1.

[0056] Example 7 A wear-resistant and high-strength polyamide material, which is different from that of Example 1 in that the aspect ratio of the carbon nanotubes in the raw materials is 150:1.

[0057] Example 8 A wear-resistant and high-strength polyamide material, which is different from that of Example 1 in that the aspect ratio of the carbon nanotubes in the raw materials is 200:1.

[0058] Example 9 A wear-resistant and high-strength polyamide material, which is different from that of Example 1 in that the aspect ratio of the carbon nanotubes in the raw materials is 300:1.

[0059] Example 10 A wear-resistant and high-strength polyamide material, which is different from that of Example 1 in that the organosilane-modified montmorillonite is prepared in Preparation Example 2.

[0060] Example 11 A wear-resistant and high-strength polyamide material, which is different from that of Example 1 in that the raw materials further include 10.5 kg of calcium carbonate microspheres, the calcium carbonate microspheres are prepared in Preparation Example 7, and the calcium carbonate microspheres are added from the side feeding port in Zone 4.

[0061] Example 12 A wear-resistant and high-strength polyamide material, which is different from that of Example 1 in that the raw materials further include 0.61 kg of 1-pyrenebutyric acid, and the carbon nanotubes are modified carbon nanotubes modified with 1-pyrenebutyric acid.

[0062] The preparation steps of the modified carbon nanotubes are as follows: Add carbon nanotubes and 1-pyrenebutyric acid into DMF solvent; treat with ultrasonic at 40 kHz for 2 h, and centrifuge to remove undispersed carbon nanotubes; after vacuum drying, break up to obtain modified carbon nanotubes.

[0063] Example 13 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that the raw materials further include 0.95 kg of p-phenylenediamine, and p-phenylenediamine is added at the side feeding port in Zone 5.

[0064] Example 14 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that the raw materials further include 1.2 kg of triglyceride borate, and an ethanol solution of triglyceride borate with a concentration of 20 wt% is added at the side feeding port in Zone 5.

[0065] Example 15 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that the raw materials further include 10.5 k of calcium carbonate microspheres and 0.61 kg of 1-pyrenebutyric acid.

[0066] The calcium carbonate microspheres are prepared by Preparation Example 7, and the calcium carbonate microspheres are added from the side feeding port in Zone 4.

[0067] The carbon nanotubes are 1-pyrenebutyric acid-modified carbon nanotubes, and the preparation steps of the modified carbon nanotubes are as follows: Add carbon nanotubes (aspect ratio 180:1) and 1-pyrenebutyric acid into DMF solvent, and treat with ultrasonic at 40 kHz for 3 h; After vacuum drying, break up to obtain modified carbon nanotubes.

[0068] Example 16 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that the raw materials further include 0.95 kg of p-phenylenediamine and 1.2 kg of triglyceride borate.

[0069] p-Phenylenediamine is added at the side feeding port in Zone 5.

[0070] Triglyceride borate is added in the form of an ethanol solution of triglyceride borate with a concentration of 20 wt% at the side feeding port in Zone 5.

[0071] Example 17 A wear-resistant and high-strength polyamide material, which is different from Example 1 in that the raw materials further include 10.5 kg of calcium carbonate microspheres, 0.61 kg of 1-pyrenebutyric acid, 0.95 kg of p-phenylenediamine, and 1.2 kg of triglyceride borate.

[0072] The calcium carbonate microspheres are prepared by Preparation Example 7, and the calcium carbonate microspheres are added from the side feeding port in Zone 4.

[0073] The carbon nanotubes are modified carbon nanotubes modified with 1-pyrenebutyric acid. The preparation steps of the modified carbon nanotubes are as follows: Add carbon nanotubes (aspect ratio 180:1) and 1-pyrenebutyric acid into DMF solvent; treat with ultrasound at 40 kHz for 2 h, and centrifuge to remove undispersed carbon nanotubes; After vacuum drying, break up to obtain modified carbon nanotubes.

[0074] p-Phenylenediamine is added at the side feeding port in Zone 5.

[0075] Triglycerol borate is added at the side feeding port in 5 as an ethanol solution of 20 wt% triglycerol borate.

[0076] Example 18 A wear-resistant and high-strength polyamide material, which is different from Example 17 in the amounts of raw materials used. Specifically: 60 kg of polyhexamethylene adipamide, 45 kg of polyamide 6, 12 kg of polylauryl lactam, 0.3 kg of sodium phenylphosphinate, 2 kg of organosilane-modified montmorillonite, 4.2 kg of carbon nanotubes, 8 kg of calcium carbonate microspheres, 0.5 kg of 1-pyrenebutyric acid, 0.8 kg of p-phenylenediamine, 1 kg of triglycerol borate.

[0077] Example 19 A wear-resistant and high-strength polyamide material, which is different from Example 17 in the amounts of raw materials used. Specifically: 70 kg of polyhexamethylene adipamide, 48 kg of polyamide 6, 15 kg of polylauryl lactam, 0.42 kg of sodium phenylphosphinate, 3.2 g of organosilane-modified montmorillonite, 5.6 kg of carbon nanotubes, 12 kg of calcium carbonate microspheres, 0.73 kg of 1-pyrenebutyric acid, 1.1 kg of p-phenylenediamine, 1.4 kg of triglycerol borate.

[0078] The polyamide materials of Examples 1 to 19 and Comparative Examples 1 to 5 are tested for mechanical strength and wear resistance.

[0079] Tensile strength: Tested according to ASTM D638.

[0080] Flexural strength: Tested according to ASTM D790.

[0081] Wear resistance test: Taber abrasion test is carried out according to ASTM D4060, using a CS-10 grinding wheel, 1 kg load, 1000 revolutions, and the result is expressed as the Taber abrasion loss. The smaller the Taber abrasion loss, the better the wear resistance.

[0082] The test results are shown in the following table.

[0083] Table 1. Test result table of Examples 1 to 19 and Comparative Examples 1 to 5 Comparing Example 1 with Comparative Examples 1-5, the tensile strength, flexural strength, and notched impact strength of Example 1 are significantly greater than those of Comparative Examples 1-5, and the Taber abrasion loss of Example 1 is significantly less than that of Comparative Examples 1-4. Therefore, the wear resistance and strength properties of Example 1 are significantly superior to those of Comparative Examples 1-5. The reason is that sodium phenylphosphinate and organosilane-modified montmorillonite are added in this application. Sodium phenylphosphinate can induce the formation of the rigid α-crystalline form of polyamide, and organosilane-modified montmorillonite can induce the formation of the tough network γ-crystalline form. Thus, the two crystalline forms are blended to form a bicontinuous phase structure, which simultaneously improves the tensile strength and impact strength of polyamide. In addition, carbon nanotubes are added in this application. Carbon nanotubes can significantly improve the wear resistance of polyamide materials. At the same time, in this application, the carbon nanotubes also guide the growth of the crystalline form along the orientation of the carbon nanotubes, adjust the orientation arrangement along the shear direction during the melt processing, provide a directional template for grain growth, optimize the crystalline form distribution, and further improve the strength properties of polyamide materials. Therefore, the polyamide of this application has high wear resistance and high strength properties.

[0084] The particle size of organosilane-modified montmorillonite will affect its dispersion uniformity in polyamide materials, and thus affect the induction result of organosilane-modified montmorillonite on the crystalline form. The applicant has studied the influence of organosilane-modified montmorillonite on the polyamide materials of this application.

[0085] Comparing Example 1 with Examples 2-5, the tensile strength from high to low is Example 1, Example 4, Example 3, Example 2, Example 5 in turn; the flexural strength from high to low is Example 1, Example 4, Example 3, Example 2, Example 5 in turn; the notched impact strength from high to low is Example 1, Example 4, Example 3, Example 2, Example 5 in turn; the Taber abrasion loss from low to high is Example 4, Example 3, Example 2, Example 5 in turn. Therefore, it can be seen that the particle size of organosilane-modified montmorillonite in this application is preferably 300-400 nm.

[0086] In this application, the carbon nanotubes also guide the growth of the crystalline form along the orientation of the carbon nanotubes, adjust the orientation arrangement along the shear direction during the melt processing. The applicant has studied the influence of organosilane-modified montmorillonite on the polyamide materials of this application.

[0087] Comparing Comparative Example 1 with Examples 6 to 9, it can be seen that the tensile strength from high to low is Example 8, Example 1, Example 7, Example 9, Example 6 in sequence; the flexural strength from high to low is Example 8, Example 1, Example 7, Example 9, Example 6 in sequence; the notched impact strength from high to low is Example 1, Example 8, Example 7, Example 6, Example 9 in sequence; the Taber abrasion loss from low to high is Example 1, Example 8, Example 7, Example 6, Example 9 in sequence. Therefore, in this application, a carbon nanotube aspect ratio of (150:1) to (200:1) is relatively optimal.

[0088] Comparing Comparative Example 1 with Example 10, it can be seen that the tensile strength and notched impact strength of Example 1 are both greater than those of Example 10, and the Taber abrasion loss of Example 1 is less than that of Example 10. Therefore, in this application, γ-glycidoxypropyltrimethoxysilane can inhibit the residual interlayer water molecules in organosilane-modified montmorillonite, reduce the melt flow rate fluctuation and the incorporation of small air pores in the melt during the preparation of polyamide materials, thereby affecting the distribution of carbon nanotubes and crystal forms, and thus optimizing the wear resistance and strength of polyamide materials.

[0089] Comparing Example 11 with Example 1, in addition to the raw materials of Example 1, porous calcium carbonate microspheres are added to Example 11. Its tensile strength and flexural strength are similar to those of Example 1, its notched impact strength is significantly improved compared with Example 1, and its Taber abrasion loss is significantly decreased compared with Example 1.

[0090] Therefore, the strength performance of Example 11 is optimized compared with Example 1, and the wear resistance is improved. The high-porosity calcium carbonate microspheres in this application have a structure such as a bionic cancellous bone structure, which can be embedded in the polyamide material to strengthen the structure and reduce the interlayer sliding of the friction surface during friction, thereby improving the strength and wear resistance of the polyamide material of this application.

[0091] Comparing Example 12 with Example 1, in addition to the raw materials of Example 1, 1-pyrenebutyric acid is added to Example 12. Its tensile strength, flexural strength, and notched impact strength are significantly improved compared with Example 1, and its Taber abrasion loss is decreased compared with Example 1.

[0092] Therefore, the strength performance and wear resistance of Example 12 are improved compared with Example 1. The 1-pyrenebutyric acid added in this application is used as an interfacial coupling agent. Its pyrene group enhances the interfacial bonding with the carbon nanotubes through π-π stacking, and its carboxylic acid group is covalently bonded to the nylon terminal amine group, thereby improving the dispersion uniformity of the carbon nanotubes and enhancing the wear resistance and strength of the polyamide material.

[0093] Comparing Comparative Example 13 with Example 1, p-phenylenediamine was further added to the raw materials in Comparative Example 13 compared with Example 1. Its tensile strength, flexural strength, and notched impact strength are similar to those of Example 1, and the Taber abrasion loss decreases compared with Example 1.

[0094] Therefore, the wear resistance of Comparative Example 13 is improved compared with Example 1. In the production and processing of this application, p-phenylenediamine can react with the oxidized end groups of polyamide to form cross-linked chains. The formed cross-links can undergo reversible breakage / recombination at 80 ± 10 °C, thereby absorbing the heat generated during the friction process of the polyamide material, reducing the heat softening of the polyamide material during the friction process, and further improving the wear resistance of the polyamide material.

[0095] Comparing Comparative Example 14 with Example 1, triglyceride borate was further added to the raw materials in Comparative Example 14 compared with Example 1. Its tensile strength, flexural strength, and notched impact strength are improved compared with Example 1, and the Taber abrasion loss decreases compared with Example 1.

[0096] Therefore, the strength performance and wear resistance of Comparative Example 14 are improved compared with Example 1. In this application, triglyceride borate can undergo a polycondensation reaction with the residual terminal amino groups and terminal carboxyl groups of polyamide to form borate bonds. These bonds undergo reversible dissociation at a processing temperature of 120 ± 10 °C; the reversibly dissociated cross-linking points are concentrated in the amorphous region and do not hinder the regular arrangement of PA chain segments. Therefore, the polyamide material has a high crystallinity and good strength; in addition, the reversible cross-linking endows the material with self-healing ability. When the processing or friction temperature rises, the cross-linking bonds dissociate to release internal stress, avoiding brittle fracture, and the network reconstructs after cooling, inhibiting crack propagation. Therefore, the wear resistance of the polyamide material is further improved.

[0097] This application also carried out a combination of multiple improvements. For example, in Examples 15 to 16, especially the improvement amounts of the tensile strength, flexural strength, and notched impact strength of Example 16 compared with Example 1, and the decrease amount of the Taber abrasion loss compared with Example 1 are significantly better than those of Comparative Example 13 and Comparative Example 14. When triglyceride borate and p-phenylenediamine are added simultaneously in this application, there is also a synergistic effect, which promotes the further improvement of the strength performance and wear resistance of the polyamide material of this application.

[0098] In addition, Examples 17 to 19 are relatively excellent examples of the composite improvement scheme of the present application. Their tensile strength, flexural strength, and notched impact strength are significantly greater than those of Comparative Examples 1 to 4, and the Taber abrasion amount is significantly lower than that of Comparative Examples 1 to 4. Therefore, in the present application, the raw material dosage in parts by mass is controlled as 60 to 70 parts by mass of polyhexamethylene adipamide, 45 to 48 parts by mass of polyamide 6, 12 to 15 parts by mass of polylauryl lactam, 0.3 to 0.42 parts by mass of sodium phenylphosphinate, 2 to 3.2 parts by mass of organosilane-modified montmorillonite; 4.2 to 5.6 parts by mass of carbon nanotubes, 0.8 to 1.1 parts by mass of p-phenylenediamine, 0.5 to 0.73 parts by mass of 1-pyrenebutyric acid, 8 to 12 parts by mass of calcium carbonate microspheres, and 1 to 1.4 parts by mass of triglyceryl borate. The obtained polyamide material has both excellent strength properties and wear resistance.

[0099] This specific embodiment is only an explanation of the present invention and is not a limitation thereof. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as they are within the scope of protection required by the present invention, they are protected by the Patent Law.

Claims

1. A wear-resistant, high-strength polyamide material, characterized in that: Including the following raw materials by mass: 60-70 parts by weight of polyhexamethylene adipamide, Polyamide 6 45-48 parts by mass, 12-15 parts by mass of polylaurolactam, 0.3-0.42 parts by mass of sodium phenyl hypophosphite, 2-3.2 parts by weight of organosilane-modified montmorillonite, 4.2~5.6 parts by mass of carbon nanotubes.

2. A wear-resistant, high-strength polyamide material according to claim 1, characterized in that: The organosilane used in the organosilane-modified montmorillonite is γ-glycidyloxypropyltrimethoxysilane.

3. A wear-resistant, high-strength polyamide material according to claim 2, characterized in that: It also includes 0.8 to 1.1 parts by mass of p-phenylenediamine.

4. A wear-resistant, high-strength polyamide material according to claim 1, characterized in that: The particle size of the organosilane-modified montmorillonite is 300-400 nm.

5. The wear-resistant, high-strength polyamide material according to claim 1, characterized in that: The invention also comprises 0.5 to 0.73 parts by weight of 1-pyrenebutyric acid.

6. The wear-resistant, high-strength polyamide material according to claim 1, characterized in that: The aspect ratio of the carbon nanotubes is (150:1) to (200:1).

7. The wear-resistant, high-strength polyamide material according to claim 1, characterized in that: It also includes 8-12 parts by weight of calcium carbonate microspheres, wherein the particle size of the calcium carbonate microspheres is 2-4 μm and the porosity is 43-57%.

8. The wear-resistant, high-strength polyamide material according to claim 1, characterized in that: It also includes 1 to 1.4 parts by weight of boric acid triglyceride.

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