A reinforced polyamide composite material and its preparation method and application

Abstract

A reinforced polyamide composite material comprises the following components, by weight: 40-50 parts of polyamide; 40-70 parts of glass fiber; and 7-15 parts of a compounded anti-wear agent, wherein the compounded anti-wear agent is a compound of high molecular weight polyethylene and polyethylene glycol. The present invention utilizes the compounded high molecular weight polyethylene and polyethylene glycol, and the hydroxyl groups of the polyethylene glycol can effectively improve the surface activity of the high molecular weight polyethylene during melt blending and modification, forming a stable interface structure with the polyamide and the entire material system. This effectively protects the material from external high temperature and high humidity environments, thereby improving the material's ability to maintain good mechanical properties even in high temperature and high humidity environments, and further enhancing wear resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, in particular to a reinforced polyamide composite material and a preparation method and application thereof. Background Art

[0002] Polyamide is widely used as an engineering material in various fields. With the continuous improvement of technology, the variety of products is increasing. However, with the development of modern high technology, the number of products with durability, friction resistance and complex structural design is gradually increasing, which puts higher requirements on the comprehensive performance of materials.

[0003] However, due to the inherent water absorption of polyamide composite materials, the resistance to wet heat aging needs to be improved. At the same time, the wear resistance also needs to be improved.

[0004] CN112552676A describes a gas-assisted molding polyamide composite material, comprising 37-86.7% polyamide resin, 10-40% flat glass fiber, 2-8% impact modifier, 0.5-5% ultra-high molecular weight polyethylene, 0.2-2% polyethylene glycol, 0.1-3% colorant, and 0.5-5% additives. This solution primarily utilizes polyethylene glycol to form intermolecular hydrogen bonds with polyamide, lowering the crystallization temperature of the composite material and improving its appearance. The flat glass fiber helps provide a more isotropic dispersion, improving the fluidity of the composite material. However, this solution is limited in improving heat and moisture resistance and wear resistance. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above technical defects and provide a high temperature, moisture and wear resistant reinforced polyamide composite material, as well as a preparation method and application.

[0006] The present invention is achieved through the following technical solutions:

[0007] A reinforced polyamide composite material, comprising the following components by weight:

[0008] 40-50 parts of polyamide;

[0009] 40-70 parts of glass fiber;

[0010] Compound anti-wear agent 7-15 parts;

[0011] The compound wear-resistant agent is a compound of high molecular weight polyethylene and polyethylene glycol, and the weight ratio of high molecular weight polyethylene to polyethylene glycol is (0.79-1.8):1;

[0012] The viscosity-average molecular weight of the high molecular weight polyethylene is 800,000-2.1 million;

[0013] The weight average molecular weight of the polyethylene glycol is 900-13000.

[0014] The polyamide content that can achieve the purpose of the present invention can be 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts. The glass fiber content can be 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, etc. The content of the compound wear-resistant agent can be 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, etc.

[0015] The weight ratio of high molecular weight polyethylene:polyethylene glycol can be 0.79:1, 0.85:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, etc.

[0016] The viscosity-average molecular weight of high molecular weight polyethylene can be 800,000, 900,000, 1,0 ...100,000, 1,200,000, 1,300,000, 1,400,000, 1,500,000, 1,600,000, 1,700,000, 1,800,000, 1,900,000, 2,000,000, 2,100,000, etc.

[0017] The weight average molecular weight of polyethylene glycol can be 900, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, etc.

[0018] In the technical solution of the present invention, the polyamide accounts for no less than 30 wt % of the total weight of the reinforced polyamide composite material.

[0019] In the present invention, the content of high molecular weight polyethylene is in the range of 3.1-9.8 parts, and the content of polyethylene glycol is in the range of 2.4-8.3 parts.

[0020] The high molecular weight polyethylene content can be 3.1 parts, 3.5 parts, 4.0 parts, 4.5 parts, 5.0 parts, 5.5 parts, 6.0 parts, 6.5 parts, 7.0 parts, 7.5 parts, 8.0 parts, 8.5 parts, 9.0 parts, 9.8 parts, etc. The polyethylene glycol content can be 2.4 parts, 3.0 parts, 3.5 parts, 4.0 parts, 4.5 parts, 5.0 parts, 5.5 parts, 6.0 parts, 6.5 parts, 7.0 parts, 7.5 parts, 8.0 parts, 8.3 parts, etc.

[0021] Preferably, the weight ratio of high molecular weight polyethylene:polyethylene glycol is (1.1-1.5):1.

[0022] Preferably, the viscosity-average molecular weight of the high molecular weight polyethylene is 1.5 million to 2 million.

[0023] Preferably, the weight average molecular weight of the polyethylene glycol is 3000-9000.

[0024] The test method for viscosity-average molecular weight of polyethylene is: GB / T1632.3-2010.

[0025] The weight-average molecular weight of polyethylene glycol is determined as follows: Weigh appropriate amounts of molecular weight reference standards (PEG 600, PEG 1000, PEG 4000, PEG 7000, and PEG 10000), dissolve them in the mobile phase, and dilute to a solution containing approximately 2 mg per 1 ml, which serves as the reference solution. Weigh appropriate amounts of sample, dissolve them in the mobile phase, and dilute to a solution containing approximately 2 mg per 1 ml, which serves as the test solution. Size exclusion chromatography (General Method 0514) is used for determination using a gel column with an appropriate separation range, 0.1 mol / L sodium nitrate solution (containing 0.02% antibacterial agent) as the mobile phase, and a differential refractive index detector. The detector and column temperatures are maintained at 35°C. 100 μl of each reference solution is injected into the liquid chromatograph, and the chromatogram is recorded. The regression equation is calculated using the GPC software. The linear correlation coefficient (R) should be no less than 0.99. Take 100 μl of the test sample solution and perform the same assay. Calculate the weight-average molecular weight and molecular weight distribution of the test sample using the regression equation. The weight-average molecular weight of the test sample should be 90%-110% of the labeled value, and the distribution coefficient should be 90%-110% of the labeled value. The antibacterial agents used are 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one (e.g., ProClin 300), or other small molecule antibacterial agents with equivalent antibacterial potency.

[0026] The polyamide resin is selected from at least one of aliphatic polyamide resin, semi-aromatic polyamide resin and polylactam resin.

[0027] The aliphatic polyamide resin is selected from PA66, PA46, PA610, PA612, PA56, PA510, PA512, PA910, PA912, PA913, PA914, PA915, PA616, PA936, PA1010, PA1012, PA1013, PA1014, PA1210, PA1212, PA1213, PA1214, PA614, PA613, PA615, PA616 and the like.

[0028] The semi-aromatic polyamide is selected from PA MXD6, PA10T, PA10T1010, PA10T66, PA6T, PA6T66, PA9T and the like.

[0029] The polylactam is selected from PA5, PA6, PA11, PA12 and the like.

[0030] Calculated by weight percentage, the invention further comprises 0-5 parts of an auxiliary agent, wherein the auxiliary agent is selected from at least one of a lubricant, a nucleating agent and an antistatic agent.

[0031] The preparation method of the reinforced polyamide composite material of the present invention comprises the following steps: uniformly mixing polyamide and a wear-resistant agent according to a ratio, feeding the mixture into a twin-screw extruder for melt mixing, side-feeding glass fiber, and extruding and granulating to obtain the reinforced polyamide composite material; wherein the twin-screw extruder has a screw length-diameter ratio of 40-48:1, a screw barrel temperature of 230-260°C, and a screw speed of 200-550 rpm.

[0032] The reinforced polyamide composite material of the present invention is used for preparing electrical appliance housings and high-temperature, high-humidity and wear-resistant parts in the new energy field.

[0033] The present invention has the following beneficial effects:

[0034] The present invention adds high molecular weight polyethylene and polyethylene glycol in a specific ratio to the reinforced polyamide composite material. During melt blending and modification, the hydroxyl groups of the polyethylene glycol can effectively improve the activity of the high molecular weight polyethylene surface, form a stable interface structure with the polyamide and the glass fiber, effectively protect the material from the influence of the external high temperature and high humidity environment, and significantly improve the wear resistance, thereby improving the material's performance retention rate after being exposed to high temperature and high humidity environments. DETAILED DESCRIPTION

[0035] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0036] The raw materials used in the present invention come from the following sources:

[0037] PA66: PA66 EPR27, Shenma Group;

[0038] PA6: PA6 HY-2800A, marine chemical fiber;

[0039] PA10T: VICNYL 6100P, Zhuhai Wantong Special Engineering Plastics Co., Ltd.

[0040] PA1010: PA1010 G150, Shandong Guangyin New Materials Co., Ltd.;

[0041] High molecular weight polyethylene A: viscosity-average molecular weight of approximately 1.2 million, PE-UHMW I-2, Sinopec;

[0042] High molecular weight polyethylene B: viscosity-average molecular weight of approximately 1.57 million, PE-UHMW MI, Sinopec;

[0043] High molecular weight polyethylene C: viscosity-average molecular weight about 400,000, GUR 2105, Celanese;

[0044] High molecular weight polyethylene D: viscosity-average molecular weight about 6.7 million, GUR 4130, Celanese;

[0045] Polyethylene glycol A: weight average molecular weight 1000, PEG-1000, Shanghai Haoyuan Biopharmaceutical Technology Co., Ltd.;

[0046] Polyethylene glycol B: weight average molecular weight 4000, PEG-4000, Shanghai Haoyuan Biopharmaceutical Technology Co., Ltd.;

[0047] Polyethylene glycol C: weight average molecular weight 8000, PEG-8000, Shanghai Haoyuan Biopharmaceutical Technology Co., Ltd.;

[0048] Polyethylene glycol D: weight average molecular weight 10000, PEG-10000, Shanghai Haoyuan Biopharmaceutical Technology Co., Ltd.;

[0049] Polyethylene glycol E: weight average molecular weight 500, PEG-500, Shanghai Haoyuan Biopharmaceutical Technology Co., Ltd.;

[0050] Polyethylene glycol F: weight average molecular weight 15000, PEG-15000, Shanghai Haoyuan Biopharmaceutical Technology Co., Ltd.;

[0051] Glass fiber: ECS10-3.0-T435N, Taishan Group.

[0052] The present invention relates to a method for preparing a reinforced polyamide composite material. The polyamide and the wear-resistant agent are uniformly mixed according to a ratio, put into a twin-screw extruder for melt mixing, side-fed with glass fiber, and extruded and granulated to obtain a reinforced polyamide composite material. The twin-screw extruder has a screw length-diameter ratio of 44:1, a barrel temperature of 230-260°C, and a screw speed of 350 rpm.

[0053] Various test methods:

[0054] (1) Abrasion resistance: The test was conducted on a color fastness wear tester, with a weight of 226N applied and 80-grit coarse sandpaper used as the grinding surface. The test was conducted at a frequency of 1 time / s, a cycle mileage of 100mm, and 5000 cycles. The wear rate of the test sample was measured. The wear rate test method is as follows:

[0055] Wear rate = (sample weight before test - sample weight after test) / sample weight before test * 100%.

[0056] (2) Resistance to heat and humidity aging: Heat and humidity aging test is conducted at a temperature of 60 degrees and a humidity of 85% for 200 hours. The tensile strength retention of the material before and after the test is compared according to ISO 527 standard.

[0057] The specific calculation formula is as follows: Performance retention rate = (tensile strength after wet heat test / tensile strength before wet heat test) / 100%.

[0058] Table 1: Content (parts by weight) of each component of the reinforced polyamide composite material of Examples 1-7 and test results

[0059] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 PA66 45 45 45 45 PA6 40 PA10T 45 PA1010 50 fiberglass 50 40 60 70 50 50 50 High molecular weight polyethylene A 6.3 3.7 5.3 7.9 5.3 7.2 7.7 Polyethylene glycol A 5.7 3.3 4.7 7.1 6.7 4.8 4.3 Polyethylene:polyethylene glycol weight ratio 1.1 1.1 1.1 1.1 0.8 1.5 1.8 Wear rate / % 1.5 1.7 1.6 2.1 1.7 1.6 1.9 Performance retention rate / % 85 84 85 80 82 87 80

[0060] It can be seen from Examples 1 / 5 / 6 / 7 that the preferred weight ratio of high molecular weight polyethylene:polyethylene glycol is (1.1-1.5):1, which has the highest wear resistance and tensile strength retention after wet heat aging.

[0061] Table 2: Content (parts by weight) of each component in the reinforced polyamide composite materials of Examples 8-11 and test results

[0062] Example 8 Example 9 Example 10 Example 11 PA66 45 45 45 45 fiberglass 50 50 50 50 High molecular weight polyethylene A 6.3 6.3 6.3 High molecular weight polyethylene B 6.3 Polyethylene glycol A 5.7 Polyethylene glycol B 5.7 Polyethylene glycol C 5.7 Polyethylene glycol D 5.7 Polyethylene:polyethylene glycol weight ratio 1.1 1.1 1.1 1.1 Wear rate / % 1.4 1.6 1.4 1.9 Retention rate of heat and humidity aging resistance / % 87 86 85 80

[0063] As can be seen from Examples 1 / 8, the viscosity-average molecular weight of the high molecular weight polyethylene is preferably 1.5 million to 2 million.

[0064] It can be seen from Examples 1 / 9 / 10 / 11 that the preferred weight average molecular weight range of polyethylene glycol is 3000-9000.

[0065] It can be seen from the above examples that the wear rate of the reinforced polyamide composite material of the present invention is less than 2%, and the tensile strength performance retention rate after wet heat aging is ≥80%.

[0066] Table 3: Content of each component (parts by weight) and test results of comparative reinforced polyamide composite materials

[0067] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 PA66 45 45 45 45 45 45 fiberglass 50 50 50 50 50 50 High molecular weight polyethylene A 6.3 6.3 3 8 High molecular weight polyethylene C 6.3 High molecular weight polyethylene D 6.3 Polyethylene glycol A 5.7 5.7 9 4 Polyethylene glycol E 5.7 Polyethylene glycol F 5.7 Polyethylene:polyethylene glycol weight ratio 1.1 1.1 1.1 1.1 0.3 2 Wear rate / % 4.3 2.2 6.8 5.7 4.0 3.4 Performance retention rate / % 73 55 60 58 53 49

[0068] It can be seen from Comparative Example 1 that when the viscosity-average molecular weight of the high molecular weight polyethylene is too low, the wear resistance and the resistance to wet heat aging are significantly reduced.

[0069] It can be seen from Comparative Example 2 that when the viscosity-average molecular weight of the high molecular weight polyethylene is too high, it is easy to crosslink during the melt processing, resulting in a slight decrease in wear resistance, especially a significant decrease in the resistance to wet heat aging.

[0070] It can be seen from Comparative Examples 3 / 4 that when the weight average molecular weight of polyethylene glycol is too high or too low, the wear resistance and the resistance to wet heat aging are simultaneously reduced.

[0071] It can be seen from Comparative Examples 5 / 6 that if the ratio of high molecular weight polyethylene to polyethylene glycol is not within the range of the present invention, the wear resistance and resistance to wet heat aging are poor.

Claims

1. A reinforced polyamide composite material, characterized in that: Calculated by weight, it includes the following components: 40-50 parts of polyamide; 40-70 parts of glass fiber; Compound anti-wear agent 7-15 parts; The compound wear-resistant agent is a compound of high molecular weight polyethylene and polyethylene glycol, and the weight ratio of high molecular weight polyethylene: polyethylene glycol is (0.79-1.8):1; The viscosity-average molecular weight of the high molecular weight polyethylene is 1 million to 2.1 million; The weight average molecular weight of the polyethylene glycol is 900-11000.

2. The reinforced polyamide composite material according to claim 1, characterized in that The weight ratio of high molecular weight polyethylene: polyethylene glycol is (1.1-1.5):

1.

3. The reinforced polyamide composite material according to claim 1, characterized in that The viscosity-average molecular weight of the high molecular weight polyethylene is 1.5 million to 2 million.

4. The reinforced polyamide composite material according to claim 1, characterized in that The weight average molecular weight of the polyethylene glycol is 3000-9000.

5. The reinforced polyamide composite material according to claim 1, characterized in that: The polyamide resin is selected from at least one of aliphatic polyamide resin and semi-aromatic polyamide resin.

6. The reinforced polyamide composite material according to claim 1, characterized in that: The polyamide resin is selected from polylactam resin.

7. The reinforced polyamide composite material according to claim 1, characterized in that: Calculated by weight percentage, the invention further comprises 0-5 parts of an auxiliary agent, wherein the auxiliary agent is selected from at least one of a lubricant, a nucleating agent and an antistatic agent.

8. The method for preparing the reinforced polyamide composite material according to any one of claims 1 to 6, characterized in that: The following steps are involved: The polyamide and the wear-resistant agent are uniformly mixed according to a ratio, fed into a twin-screw extruder for melt mixing, and fed with glass fiber on the side, and extruded into pellets to obtain a reinforced polyamide composite material; wherein the twin-screw extruder has a screw length-diameter ratio of 40-48:1, a screw barrel temperature of 230-260°C, and a screw speed of 200-550 rpm.

9. Use of the reinforced polyamide composite material according to any one of claims 1 to 6, characterized in that: Used to prepare electrical appliance casings and high temperature and high humidity resistant components in the new energy field.