A method for preparing high-strength, low-water-absorption nylon 66
By forming a cross-linked network structure under electron beam irradiation, the problems of tensile strength and water absorption of glass fiber reinforced nylon 66 were solved, realizing the preparation of high-strength, low-water-absorption nylon 66 and improving the mechanical properties and dimensional stability of the material.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGSU YANGNONG CHEMICAL GROUP CO LTD
- Filing Date
- 2026-04-27
- Publication Date
- 2026-06-02
AI Technical Summary
Existing technologies cannot effectively reduce the water absorption rate of glass fiber reinforced nylon 66 while improving its tensile strength. Conventional methods may affect the mechanical properties of the material or increase costs.
Using cerium methacrylate, silane coupling agent KH151, and glass fiber as raw materials, a cross-linked network structure is formed under electron beam irradiation to improve the interfacial bonding force between glass fiber and nylon 66, thus preparing high-strength, low-water-absorption nylon 66.
It significantly improves the tensile strength of Nylon 66 and reduces water absorption, enhances the dimensional stability of the material, and has high production efficiency, no pollution, and is suitable for large-scale production.
Smart Images
Figure CN122127782A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of modified nylon material preparation technology, and in particular to a method for preparing high-strength, low-water-absorption nylon 66. Background Technology
[0002] Glass fiber reinforced nylon 66 (polyhexamethylene adipamide) is a high-performance engineering plastic that is widely used in the automotive, electronics, and machinery industries due to its high strength, high rigidity, wear resistance, heat resistance, and good dimensional stability.
[0003] However, glass fiber is incompatible with the nylon 66 matrix, which affects the reinforcing effect of glass fiber on nylon 66. In addition, nylon 66 material has strong hygroscopic properties. Although glass fiber reinforcement can reduce hygroscopicity to some extent, the dimensional changes caused by moisture absorption still exist.
[0004] Currently, methods to reduce the water absorption rate of glass fiber reinforced nylon 66 mainly focus on technologies such as material modification, process optimization, and post-treatment.
[0005] Adding hydrophobic additives or modifiers to nylon 66 can reduce the material's water absorption rate, altering its affinity for water at the molecular level. While adding additives or modifiers can reduce the water absorption rate of glass fiber reinforced nylon 66, it also reduces the mechanical properties of the material, thus affecting its performance in use.
[0006] For example, a hydrophobic coating can be applied to the surface of glass fiber reinforced nylon 66 products to reduce the overall moisture absorption of the material. However, this method of applying a hydrophobic coating to the surface of glass fiber reinforced nylon 66 products increases the processing steps and material costs, resulting in low economic benefits.
[0007] Another method to reduce the hygroscopicity of glass fiber reinforced nylon 66 materials is to modify its molecular structure. However, this method, by altering the molecular structure of nylon 66, can easily lead to a decrease in the processing performance of glass fiber reinforced nylon 66 materials, thus affecting the material's performance in use.
[0008] Alternatively, methods exist to add certain inorganic salts or antihypertensive materials as moisture inhibitors during the processing of glass fiber reinforced nylon 66 materials, which can effectively reduce the material's hygroscopicity. However, this method also reduces the mechanical properties of glass fiber reinforced nylon 66 materials due to the addition of moisture inhibitors, thus affecting the material's performance in use.
[0009] Therefore, there is an urgent need for a method to prepare high-strength, low-water-absorption nylon 66 that can both further improve the tensile strength of glass fiber reinforced nylon 66 and reduce water absorption. Summary of the Invention
[0010] The technical problem to be solved by the present invention is to provide a method for preparing high-strength, low-water-absorption nylon 66 that can both further improve the tensile strength of glass fiber reinforced nylon 66 and reduce water absorption.
[0011] To solve the above-mentioned technical problems, the present invention provides a method for preparing high-strength, low-water-absorption nylon 66, comprising the following steps: Cerium methacrylate was prepared by reacting water, methacrylic acid, and cerium carbonate as raw materials. Cerium methacrylate, silane coupling agent KH151, glass fiber and dried nylon 66 were mixed to obtain a mixture. The mixture is melt-extruded through a twin-screw extruder and then granulated by a pelletizer to obtain granulated mixture. The mixture of granules is injection molded into injection-molded samples using an injection molding machine. High-strength, low-water-absorption nylon 66 was obtained by electron beam irradiation of injection-molded samples.
[0012] Furthermore, the molar ratio of water, methacrylic acid, and cerium carbonate is 50:8:1.
[0013] Furthermore, the reaction temperature of water, methacrylic acid, and cerium carbonate is 65-75℃, and the reaction time is 1-2 hours.
[0014] Further, after the reaction of water, methacrylic acid, and cerium carbonate is completed, the mixture is filtered while hot, and the filtrate is distilled under reduced pressure to remove water. Then, anhydrous ethanol is added to dissolve the filtrate, and the mixture is distilled under reduced pressure and dried to obtain cerium methacrylic acid powder.
[0015] Furthermore, the vacuum distillation temperature is 65-75℃, the vacuum degree is -0.08-0.09Mpa, and the drying is carried out in a forced-air drying oven at 70-80℃.
[0016] Furthermore, the mixture contains 1-3 wt% cerium methacrylate, 0.1 wt% silane coupling agent KH151, 30% glass fiber, and 66.9-68.9 wt% dried nylon 66.
[0017] Furthermore, the dried nylon 66 is obtained by drying nylon 66 in a vacuum drying oven at a temperature of 130℃±2℃ for 4h±15min, and then placing the dried nylon 66 in a desiccator to cool to room temperature.
[0018] Furthermore, when the mixture is melt-extruded through a twin-screw extruder, the screw speed of the twin-screw extruder is 40-60 r / min, and the temperature of the screw in zone one is 180-190℃, zone two is 235-245℃, zone three is 250-260℃, zone four is 250-260℃, and zone five is 250-260℃.
[0019] Furthermore, when the mixture granules are injection molded by an injection molding machine, the barrel temperature of the injection molding machine is 250-300℃, the mold temperature is 50-70℃, and the holding pressure is 50-70 MPa.
[0020] Furthermore, the electron beam energy of the injection-molded sample during electron beam irradiation is 10 MeV, the dose rate is 10 kGy / min, the irradiation dose is 50-100 kGy, and the irradiation time is 5-15 min.
[0021] This invention provides a method for preparing high-strength, low-water-absorption nylon 66. Using cerium methacrylate, silane coupling agent KH151, glass fiber, and dried nylon 66 as raw materials, high-strength, low-water-absorption nylon 66 is prepared under electron beam irradiation. Specifically, silane coupling agent KH151 couples with the hydroxyl groups on the glass fiber surface, and cerium ions in cerium methacrylate coordinate with the amide matrix in nylon 66. Under electron beam irradiation, the carbon-carbon double bonds in cerium methacrylate polymerize with the carbon-carbon double bonds on KH151, further improving the interfacial bonding between the glass fiber and nylon 66, enhancing the reinforcing effect of the glass fiber, and thus increasing the tensile strength of nylon 66. Furthermore, the formation of a dense cross-linked network structure within the glass fiber nylon 66 material under electron beam irradiation reduces the material's water absorption rate.
[0022] Therefore, the present invention provides a method for preparing high-strength, low-water-absorption nylon 66, which uses cerium methacrylate (Ce(MAA)3) as an irradiation crosslinking agent, silane coupling agent KH151 as an auxiliary crosslinking agent and coupling agent, and improves the bonding force between glass fiber and nylon 66 under electron beam irradiation, thereby enhancing the reinforcing effect of glass fiber and further improving the tensile strength of nylon 66.
[0023] Furthermore, the present invention provides a method for preparing high-strength, low-water-absorption nylon 66. During the electron beam irradiation modification process, a cross-linked network structure can be formed within the nylon 66, significantly reducing the material's water absorption rate and thus improving the material's dimensional stability during use. Moreover, the irradiation dose during the electron beam irradiation modification process is easy to control, the irradiation time is short, production efficiency is high, there is no pollution, and large-scale production is possible. Attached Figure Description
[0024] Figure 1This is a flowchart illustrating a method for preparing high-strength, low-absorption nylon 66 according to an embodiment of the present invention. Detailed Implementation
[0025] See Figure 1 The present invention provides a method for preparing high-strength, low-absorption nylon 66, comprising the following steps: Step 1) Prepare cerium methacrylate by reacting water, methacrylic acid, and cerium carbonate as raw materials.
[0026] The molar ratio of water, methacrylic acid, and cerium carbonate in the reaction raw materials is 50:8:1.
[0027] Furthermore, the reaction of water, methacrylic acid, and cerium carbonate takes place at a temperature of 65-75℃ for 1-2 hours.
[0028] After the reaction of water, methacrylic acid, and cerium carbonate is completed, the mixture is filtered while hot. The filtrate is then distilled under reduced pressure to remove water. Anhydrous ethanol is added to dissolve the filtrate, and the mixture is distilled under reduced pressure and dried to obtain a white powder of cerium methacrylic acid.
[0029] In one specific embodiment of the present invention, the temperature during vacuum distillation is 65-75℃, the vacuum degree is -0.08-0.09Mpa, and the drying after vacuum distillation is carried out in a forced-air drying oven at 70-80℃.
[0030] Step 2) Mix cerium methacrylate, silane coupling agent KH151, glass fiber and dried nylon 66 to obtain a mixture.
[0031] The mixture contains, by mass percentage, 1-3 wt% cerium methacrylate, 0.1 wt% silane coupling agent KH151, 30% glass fiber, and 66.9-68.9 wt% dried nylon 66.
[0032] The drying of nylon 66 involves drying it in a vacuum drying oven at a temperature of 130℃±2℃ for 4 hours±15 minutes, and then placing the dried nylon 66 in a desiccator to cool it to room temperature.
[0033] Drying nylon 66 can prevent material degradation due to the presence of water during subsequent processing such as extrusion or injection molding.
[0034] Step 3) The mixture is melt-extruded through a twin-screw extruder and granulated through a pelletizer to obtain granulated mixture.
[0035] When the mixture is melt-extruded through a twin-screw extruder, the screw speed of the twin-screw extruder is 40-60 r / min, and the temperature of the screw is 180-190℃ in zone 1, 235-245℃ in zone 2, 250-260℃ in zone 3, 250-260℃ in zone 4, and 250-260℃ in zone 5.
[0036] In a preferred embodiment of the present invention, when the mixture is melt-extruded through a twin-screw extruder, the screw speed of the twin-screw extruder is 50 r / min, and the temperature of the screw in zone one is 185°C, zone two is 240°C, zone three is 255°C, zone four is 255°C, and zone five is 255°C.
[0037] Step 4) The mixture of granules is injection molded into injection molding samples using an injection molding machine; When the mixed granules are injection molded by the injection molding machine, the barrel temperature of the injection molding machine is 250-300℃, the mold temperature is 50-70℃, and the holding pressure is 50-70Mpa.
[0038] Step 5) Irradiate the injection-molded sample with an electron beam to obtain high-strength, low-water-absorption nylon 66; The electron beam energy for electron beam irradiation of the injection-molded sample was 10 MeV, the dose rate was 10 kGy / min, the irradiation dose was 50-100 kGy, and the irradiation time was 5-15 min.
[0039] This invention provides a method for preparing high-strength, low-water-absorption nylon 66. The method uses cerium methacrylate, silane coupling agent KH151, glass fiber, and dried nylon 66 as raw materials and prepares the high-strength, low-water-absorption nylon 66 under electron beam irradiation. Specifically, the silane coupling agent KH151 couples with the hydroxyl groups on the surface of the glass fiber, and the cerium ions in the cerium methacrylate coordinate with the amide matrix in the nylon 66. Under electron beam irradiation, the carbon-carbon double bonds in the cerium methacrylate polymerize with the carbon-carbon double bonds on KH151, further improving the interfacial bonding between the glass fiber and nylon 66, enhancing the reinforcing effect of the glass fiber, and thus increasing the tensile strength of the nylon 66. Furthermore, the formation of a dense cross-linked network structure within the glass fiber nylon 66 material under electron beam irradiation reduces the material's water absorption rate.
[0040] The following examples illustrate a specific method for preparing a high-strength, low-absorption nylon 66 provided by the present invention.
[0041] Example 1 1) Add water, methacrylic acid, and cerium carbonate to a three-necked flask in sequence, heat to 70°C and stir in a water bath for 1.5 h, filter while hot, distill the filtrate under reduced pressure to remove water, add anhydrous ethanol to dissolve, continue to distill under reduced pressure and dry to obtain white powder cerium methacrylic acid.
[0042] 2) Weigh 500g of Nylon 66 particles using an electronic balance and dry them in a vacuum drying oven at 130℃±2℃ for 4h±15min. Then place them in a desiccator to cool to room temperature.
[0043] 3) Weigh 1 wt% of pre-prepared cerium methacrylate (5.00 g), 0.1 wt% of silane coupling agent KH151 (0.5 g), 30 wt% of glass fiber (150 g), and 68.9 wt% of pre-prepared dried nylon 66 (344.5 g) using an electronic balance, and mix them evenly in a high-speed mixer.
[0044] 4) The mixed material is melt-extruded through a twin-screw extruder and granulated by a pelletizer to obtain modified nylon 66 particles. The processing parameters of the twin-screw extruder are as follows: screw speed: 50 r / min; screw temperature: zone 1 185℃, zone 2 240℃, zone 3 255℃, zone 4 255℃, zone 5 255℃.
[0045] 5) The prepared modified nylon 66 particles were dried and then injection molded into test strips using an injection molding machine. The injection molding parameters were: barrel temperature 280℃, mold temperature 60℃, and holding pressure 60MPa.
[0046] 6) Irradiate the injection-molded sample with an electron beam energy of 10 MeV, a dose rate of 10 kGy / min, and an irradiation dose of 100 kGy to obtain electron beam irradiated modified nylon 66.
[0047] The high-strength, low-water-absorption nylon 66 (i.e., the electron beam irradiated modified nylon 66) obtained in the embodiments of the present invention was subjected to tensile strength testing according to the method specified in the national standard GBT1447-2005 Test Method for Tensile Properties of Fiber Reinforced Plastics. The tensile strength test results of the electron beam irradiated modified nylon 66 obtained in the embodiments of the present invention are shown in Table 1.
[0048] The electron beam irradiated modified nylon 66 sample was dried in an oven at 50.0℃±2.0℃ for 24h±1h, and then cooled to room temperature in a desiccator. By drying the irradiated modified nylon 66 sample, the absorption of moisture from the air during the irradiation process can be eliminated, making the water absorption rate of the sample more accurate in subsequent measurements and calculations.
[0049] Weigh the dried, irradiated, modified nylon 66 sample (mass m1). Completely immerse the sample in a container of boiling distilled water. After immersion for 30 min ± 2 min, remove the sample from the boiling water and cool it in room temperature distilled water for 15 min ± 1 min. Wipe the surface of the sample with filter paper, and repeat the immersion and weighing process every 30 min ± 2 min until the sample is saturated with water. Finally, weigh the sample after the immersion treatment is complete (mass m2). From the formula: Calculate the water absorption rate of the sample.
[0050] The water absorption rates of the high-strength, low-water-absorption nylon 66 (i.e., the electron beam irradiated modified nylon 66) obtained in the embodiments of the present invention are shown in Table 1.
[0051] Table 1
[0052] Example 2 The experiment was carried out according to the specific implementation steps of Example 1. The difference from Example 1 is that the formulation of this invention is adjusted to 2wt% cerium methacrylate (10.00g), 0.1wt silane coupling agent KH151 (0.5g), 30wt% glass fiber (150g), and 67.9wt% nylon 66 (339.5g).
[0053] The high-strength, low-water-absorption nylon 66 (i.e., the electron beam irradiated modified nylon 66) obtained in the embodiments of the present invention was subjected to tensile strength testing according to the method specified in the national standard GBT1447-2005 Test Method for Tensile Properties of Fiber Reinforced Plastics. The tensile strength test results of the electron beam irradiated modified nylon 66 obtained in the embodiments of the present invention are shown in Table 1.
[0054] The water absorption rate of the electron beam irradiated modified nylon 66 prepared in the embodiments of the present invention was tested. The water absorption rate of the high strength low water absorption nylon 66 prepared in the embodiments of the present invention (i.e., the obtained electron beam irradiated modified nylon 66) is shown in Table 1.
[0055] Example 3 The experiment was carried out according to the specific implementation steps of Example 1. The difference from Example 1 is that the formulation of this invention is adjusted to 3wt% cerium methacrylate (15.00g), 0.1wt silane coupling agent KH151 (0.5g), 30wt% glass fiber (150g), and 66.9wt% nylon 66 (334.5g).
[0056] The high-strength, low-water-absorption nylon 66 (i.e., the electron beam irradiated modified nylon 66) obtained in the embodiments of the present invention was subjected to tensile strength testing according to the method specified in the national standard GBT1447-2005 Test Method for Tensile Properties of Fiber Reinforced Plastics. The tensile strength test results of the electron beam irradiated modified nylon 66 obtained in the embodiments of the present invention are shown in Table 1.
[0057] The water absorption rate of the electron beam irradiated modified nylon 66 prepared in the embodiments of the present invention was tested. The water absorption rate of the high strength low water absorption nylon 66 prepared in the embodiments of the present invention (i.e., the obtained electron beam irradiated modified nylon 66) is shown in Table 1.
[0058] Currently, the tensile strength of glass fiber reinforced nylon 66 with a glass fiber content of 30wt% is 170-180 MPa, and the water absorption rate is 3-4%. However, as shown in Table 1, the tensile strength of the electron beam irradiated modified nylon 66 obtained in Examples 1-3 of this invention is higher than that of glass fiber reinforced nylon 66 with a glass fiber content of 30wt% currently available on the market, and the water absorption rate is lower.
[0059] Therefore, the present invention provides a method for preparing high-strength, low-water-absorption nylon 66, which uses cerium methacrylate as an irradiation crosslinking agent, silane coupling agent KH151 as an auxiliary crosslinking agent and coupling agent, and improves the bonding force between glass fiber and nylon 66 under electron beam irradiation, thereby enhancing the reinforcing effect of glass fiber and further improving the tensile strength of nylon 66.
[0060] Moreover, the method for preparing high-strength, low-water-absorption nylon 66 provided by the present invention can form a cross-linked network structure in nylon 66 during electron beam irradiation modification, which significantly reduces the water absorption rate of the material and thus improves the dimensional stability of the material during use.
[0061] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A method for preparing high-strength, low-absorption nylon 66, characterized in that, Includes the following steps: Cerium methacrylate was prepared by reacting water, methacrylic acid, and cerium carbonate as raw materials. Cerium methacrylate, silane coupling agent KH151, glass fiber and dried nylon 66 were mixed to obtain a mixture. The mixture is melt-extruded through a twin-screw extruder and then granulated by a pelletizer to obtain granulated mixture. The mixture of granules is injection molded into injection-molded samples using an injection molding machine. High-strength, low-water-absorption nylon 66 was obtained by electron beam irradiation of injection-molded samples.
2. The method for preparing high-strength, low-absorption nylon 66 according to claim 1, characterized in that, The molar ratio of water, methacrylic acid, and cerium carbonate is 50:8:
1.
3. The method for preparing high-strength, low-absorption nylon 66 according to claim 2, characterized in that, The reaction of water, methacrylic acid, and cerium carbonate is carried out at a temperature of 65-75℃ for a time of 1-2 hours.
4. The method for preparing high-strength, low-absorption nylon 66 according to claim 3, characterized in that, After the reaction of water, methacrylic acid, and cerium carbonate is completed, the mixture is filtered while hot. The filtrate is then distilled under reduced pressure to remove water. Anhydrous ethanol is added to dissolve the filtrate, and the mixture is distilled under reduced pressure and dried to obtain a white powder of cerium methacrylic acid.
5. The method for preparing high-strength, low-absorption nylon 66 according to claim 4, characterized in that, The vacuum distillation is carried out at a temperature of 65-75℃ and a vacuum degree of -0.08-0.09 MPa, and the drying is carried out in a forced-air drying oven at 70-80℃.
6. The method for preparing high-strength, low-absorption nylon 66 according to claim 1, characterized in that, The mixture contains 1-3 wt% cerium methacrylate, 0.1 wt% silane coupling agent KH151, 30% glass fiber, and 66.9-68.9 wt% dried nylon 66.
7. The method for preparing high-strength, low-absorption nylon 66 according to claim 6, characterized in that, The dried nylon 66 is obtained by drying nylon 66 in a vacuum drying oven at a temperature of 130℃±2℃ for 4h±15min, and then placing the dried nylon 66 in a desiccator to cool to room temperature.
8. The method for preparing high-strength, low-absorption nylon 66 according to claim 6, characterized in that, When the mixture is melt-extruded through a twin-screw extruder, the screw speed of the twin-screw extruder is 40-60 r / min, and the temperature of the screw is 180-190℃ in zone 1, 235-245℃ in zone 2, 250-260℃ in zone 3, 250-260℃ in zone 4, and 250-260℃ in zone 5.
9. The method for preparing high-strength, low-absorption nylon 66 according to claim 1, characterized in that, When the mixture granules are injection molded by an injection molding machine, the barrel temperature of the injection molding machine is 250-300℃, the mold temperature is 50-70℃, and the holding pressure is 50-70 MPa.
10. The method for preparing high-strength, low-absorption nylon 66 according to claim 1, characterized in that, The electron beam energy of the injection-molded sample during electron beam irradiation is 10 MeV, the dose rate is 10 kGy / min, the irradiation dose is 50-100 kGy, and the irradiation time is 5-15 min.