Low-temperature-resistant nylon plastic and preparation method thereof

Abstract

The application discloses a low-temperature-resistant nylon plastic and a preparation method thereof, and belongs to the technical field of high polymer materials. Nylon resin 90-100 parts, modified ternary ethylene-propylene rubber 20-30 parts, lubricant 1-3 parts, antioxidant 0.5-1.5 parts and ultraviolet absorber 0.5-1.5 parts are uniformly mixed in a blender, then are melt-extruded in a double-screw extruder, are water-cooled, are cut into particles, are dried, and the low-temperature-resistant nylon plastic is obtained. The maleic anhydride grafted ternary ethylene-propylene rubber realizes in-situ compatibilization of the modified ternary ethylene-propylene rubber and the nylon resin; the flame retardant containing multiple long carbon chains and the modified ternary ethylene-propylene rubber synergistically act, and excellent toughness and low-temperature resistance are endowed to the nylon plastic; in addition, the flame retardant containing nitrogen, phosphorus and silicon halogen-free flame-retardant elements also endows the nylon plastic with efficient, safe and stable and persistent flame-retardant effect. In combination with the common action of the remaining raw materials, the nylon plastic has excellent comprehensive performance.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a low-temperature resistant nylon plastic and its preparation method. Background Technology

[0002] Polyamide (PA), commonly known as nylon, has polar amide groups that can form hydrogen bonds, resulting in excellent mechanical properties, impact resistance, and relatively tough engineering plastics. This material boasts advantages such as being non-toxic, odorless, mildew-free, having high surface hardness, wear resistance, self-lubricating properties, sound absorption, good chemical stability, and good electrical insulation. Due to its superior properties, nylon is widely used in industrial manufacturing, such as in the automotive, instrumentation, machinery, and textile industries, where it is frequently used for parts and structural components.

[0003] However, nylon's flame retardancy is not very good, and it is easily flammable, yet excellent flame retardancy is required in the automotive, machinery, and textile industries. Among flame retardant modification methods, adding halogenated flame retardants is the most widely used. However, because halogenated flame retardants are unstable and can produce toxic and harmful substances, the research and development of halogen-free flame retardants is currently the focus of flame retardant research. Furthermore, nylon has poor low-temperature resistance, which limits its application range. Therefore, there is an urgent need to develop a low-temperature resistant nylon plastic with good flame retardant properties to meet market demand. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a low-temperature resistant nylon plastic and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A low-temperature resistant nylon plastic comprises the following raw materials in parts by weight: 90-100 parts nylon resin, 20-30 parts modified EPDM rubber, 1-3 parts lubricant, 0.5-1.5 parts antioxidant, and 0.5-1.5 parts ultraviolet absorber.

[0007] Furthermore, the nylon resin is one or more of nylon 6, nylon 66, nylon 610, nylon 612, nylon 1010, and nylon 1212.

[0008] Furthermore, the modified EPDM rubber is prepared through the following steps:

[0009] EPDM rubber, maleic anhydride, flame retardant, initiator and solvent are mixed evenly, and then the solvent is removed by rotary evaporation to obtain a premix. The premix is ​​melt-extruded through a twin-screw extruder, pulverized by a pelletizer and dried to prepare modified EPDM rubber.

[0010] Ethylene propylene diene monomer (EPDM) rubber not only possesses excellent heat resistance, oxygen resistance, weather resistance, and aging resistance, but also exhibits good chemical resistance, electrical insulation, and low-temperature resistance. Therefore, adding modified EPDM rubber as a raw material to nylon plastics can significantly improve the toughness and low-temperature resistance of nylon plastics. Simultaneously, introducing maleic anhydride, which can react with the amide groups on nylon, onto the EPDM rubber chain can achieve in-situ compatibilization, allowing the modified EPDM rubber to fully function in nylon plastics, thereby enhancing the toughness and low-temperature resistance of nylon plastics.

[0011] Furthermore, the ratio of the amount of EPDM rubber, maleic anhydride, flame retardant and initiator is 100g:(0.5-1.5)g:(10-15)g:(0.05-0.15)g.

[0012] Furthermore, the flame retardant is prepared by the following steps:

[0013] S1. Purge the dry three-necked flask with nitrogen for 30 minutes to remove air and moisture. Add 1-tetradecyl alcohol, tetraisopropyl titanate, and benzene to the flask and stir to dissolve. Then slowly add vinyltrimethoxysilane. After the addition is complete, heat to 90°C and react for 24 hours. After the reaction is complete, cool to room temperature and distill under reduced pressure to obtain intermediate 1. The ratio of 1-tetradecyl alcohol, vinyltrimethoxysilane, tetraisopropyl titanate, and benzene is 35.2 g: 12.3 mL: 1 mL: 180 mL.

[0014] Under the catalysis of tetraisopropyl titanate, with the molar ratio of 1-tetradecyl alcohol and vinyltrimethoxysilane controlled at 2.0-2.1:1, the hydroxyl groups of 1-tetradecyl alcohol and the silanoxy groups of vinyltrimethoxysilane undergo the following chemical reaction, as shown in the following process:

[0015]

[0016] S2. Purge the dry three-necked flask with nitrogen for 30 minutes to remove air and moisture. Add diethyl N,N-bis(2-hydroxyethyl)aminomethylenephosphonate, tetraisopropyl titanate, and dimethyl sulfoxide to the flask and stir to dissolve. Then slowly add a mixed solution of intermediate 1 and dimethyl sulfoxide. After the addition is complete, heat to 90°C and react for 26 hours. After the reaction is complete, cool to room temperature and distill under reduced pressure to obtain the flame retardant. The ratio of diethyl N,N-bis(2-hydroxyethyl)aminomethylenephosphonate, intermediate 1, tetraisopropyl titanate, and dimethyl sulfoxide is 8.9 g: 38.6 g: 0.44 mL: 200 mL.

[0017] Controlling the molar ratio of diethyl N,N-bis(2-hydroxyethyl)aminomethylenephosphonate to intermediate 1 to 1:2.1-2.2, the hydroxyl group of N,N-bis(2-hydroxyethyl)aminomethylenephosphonate and the silanoxy group of intermediate 1 undergo the following chemical reaction under the catalysis of tetraisopropyl titanate, as shown below:

[0018]

[0019] The carbon-carbon double bonds in the flame retardant react chemically with the carbon-carbon double bonds in the side chains of EPDM rubber under the action of the initiator. This results in the flame retardant being grafted onto the EPDM rubber and firmly present in the modified EPDM rubber. The multiple long carbon chains in the flame retardant increase the flexibility of the EPDM rubber molecular chain segments and significantly lower the glass transition temperature. Combined with the synergistic effect of the EPDM rubber, the modified EPDM rubber of this invention is more resistant to low temperatures, thus making the nylon plastic of this invention more resistant to low temperatures. The freely stretchable and rotatable long carbon chains also improve the toughness and tensile strength of the modified EPDM rubber, thereby improving the toughness and tensile strength of the nylon plastic. Furthermore, the flame retardant achieves high flame retardancy, low smoke emission, and low toxicity through the synergistic effect of nitrogen, phosphorus, and silicon halogen-free flame retardant elements, thus giving the nylon plastic of this invention excellent flame retardant properties.

[0020] Furthermore, the initiator is one or more of benzoyl peroxide, azobisisobutyronitrile, and dicumyl peroxide.

[0021] Furthermore, the solvent is one or more of ethanol, acetone, benzene, dimethyl sulfoxide, and N,N-dimethylformamide.

[0022] Furthermore, the lubricant is one or more of ethylene bis-stearamide, oleamide, and erucamide.

[0023] Furthermore, the antioxidant is one or more of antioxidant 1010, antioxidant 1035, antioxidant 1076, and antioxidant 168.

[0024] Furthermore, the ultraviolet absorber is one or more of ultraviolet absorber UV-P, ultraviolet absorber UV-9, ultraviolet absorber UV-531, and ultraviolet absorber UVP-327.

[0025] A method for preparing low-temperature resistant nylon plastic includes the following steps:

[0026] The nylon plastic raw materials are mixed evenly in a mixer according to the weight parts, then melt-extruded in a twin-screw extruder, cooled with water, pelletized, and dried to obtain low-temperature resistant nylon plastic.

[0027] The beneficial effects of this invention are as follows: Maleic anhydride-grafted EPDM rubber achieves in-situ compatibilization between modified EPDM rubber and nylon resin; the flame retardant containing multiple long carbon chains works synergistically with the modified EPDM rubber, endowing the nylon plastic with excellent toughness and low-temperature resistance; furthermore, the flame retardant containing nitrogen, phosphorus, and silicon halogen-free flame retardant elements also endows the nylon plastic with highly efficient, safe, stable, and long-lasting flame retardant effects. Combined with the combined effects of the remaining raw materials, the nylon plastic of this invention exhibits excellent overall performance. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1: Preparation of flame retardant, the specific steps are as follows:

[0030] S1. Purge a 500 mL dry three-necked flask with nitrogen for 30 min to remove air and moisture. Add 35.2 g of 1-tetradecyl alcohol, 1 mL of tetraisopropyl titanate and 180 mL of benzene to the flask and stir to dissolve. Then slowly add 12.3 mL of vinyltrimethoxysilane. After the addition is complete, heat to 90 °C and react for 24 h. After the reaction is complete, cool to room temperature and distill under reduced pressure to obtain intermediate 1.

[0031] S2. Purge a 500 mL dry three-necked flask with nitrogen for 30 min to remove air and moisture. Add 8.9 g of N,N-bis(2-hydroxyethyl)aminomethylenephosphonate diethyl ester, 0.44 mL of tetraisopropyl titanate, and 200 mL of dimethyl sulfoxide to the flask and stir to dissolve. Then slowly add 38.6 g of a mixed solution of intermediate 1 and dimethyl sulfoxide. After the addition is complete, heat to 90 °C and react for 26 h. After the reaction is complete, cool to room temperature and distill under reduced pressure to obtain the flame retardant.

[0032] Example 2: Preparation of modified EPDM rubber, the specific steps are as follows:

[0033] 100g of EPDM rubber, 0.5g of maleic anhydride, 10g of the flame retardant prepared in Example 1, 0.05g of azobisisobutyronitrile, and 350mL of dimethyl sulfoxide were stirred evenly, and the solvent was removed by rotary evaporation to obtain a premix. The premix was melt-extruded through a twin-screw extruder, pulverized by a pelletizer, and dried to prepare modified EPDM rubber.

[0034] Example 3: Preparation of modified EPDM rubber, the specific steps are as follows:

[0035] 100g of EPDM rubber, 1.2g of maleic anhydride, 13g of the flame retardant prepared in Example 1, 0.1g of benzoyl peroxide, 180mL of ethanol and 200mL of benzene were stirred evenly, and the solvent was removed by rotary evaporation to obtain a premix. The premix was melt-extruded through a twin-screw extruder, pulverized by a pelletizer, and dried to prepare modified EPDM rubber.

[0036] Example 4: Preparation of modified EPDM rubber, the specific steps are as follows:

[0037] 100g of EPDM rubber, 1.5g of maleic anhydride, 15g of the flame retardant prepared in Example 1, 0.15g of dicumyl peroxide, 200mL of acetone, and 200mL of N,N-dimethylformamide were stirred evenly, and the solvent was removed by rotary evaporation to obtain a premix. The premix was melt-extruded through a twin-screw extruder, pulverized by a pelletizer, and dried to prepare modified EPDM rubber.

[0038] Example 5: Preparation of nylon plastic, the specific steps are as follows:

[0039] 45 parts by weight of nylon resin, 45 parts of nylon 1010, 45 parts of nylon 1212, 20 parts of modified EPDM rubber prepared in Example 4, 1 part of ethylene bis-stearamide, 0.5 parts of antioxidant 1010, and 0.5 parts of ultraviolet absorber UV-P were mixed evenly in a mixer, then melt-extruded in a twin-screw extruder, granulated after water cooling, and dried to obtain nylon plastic.

[0040] Example 6: Preparation of nylon plastic, the specific steps are as follows:

[0041] 98 parts by weight of nylon resin, 26 parts of modified EPDM rubber prepared in Example 3, 1 part of oleamide, 1 part of erucamide, 0.6 parts of antioxidant 1035, 0.4 parts of antioxidant 1076, 0.5 parts of UV absorber UV-9, and 0.5 parts of UV absorber UV-531 were mixed evenly in a mixer, then melt-extruded in a twin-screw extruder, granulated after water cooling, and dried to obtain nylon plastic.

[0042] Example 7: Preparation of nylon plastic, the specific steps are as follows:

[0043] 80 parts by weight of nylon resin, 20 parts of nylon 6, 30 parts of modified EPDM rubber prepared in Example 2, 1 part of ethylene bis-stearamide, 1 part of oleamide, 1 part of erucamide, 1 part of antioxidant 1010, 0.5 parts of antioxidant 168, 0.5 parts of ultraviolet absorber UV-P, and 1 part of ultraviolet absorber UVP-327 were mixed evenly in a mixer, then melt-extruded in a twin-screw extruder, granulated after water cooling, and dried to obtain low-temperature resistant nylon plastic.

[0044] Comparative Example 1: Modified EPDM rubber was prepared, and the specific steps are as follows:

[0045] The remaining steps remain the same, except that the flame retardant from Example 4 is removed to prepare modified EPDM rubber.

[0046] Comparative Example 2: Modified EPDM rubber was prepared, and the specific steps are as follows:

[0047] The remaining steps remain the same, except that the flame retardant in Example 4 is replaced with 15g of ammonium polyphosphate to prepare modified EPDM rubber.

[0048] Comparative Example 3: Preparation of nylon plastic, the specific steps are as follows:

[0049] The remaining steps remain the same, except that the modified EPDM rubber in Example 5 is replaced with the modified EPDM rubber prepared in Comparative Example 1 to prepare nylon plastic.

[0050] Comparative Example 4: Preparation of nylon plastic, the specific steps are as follows:

[0051] The remaining steps remain the same, except that the modified EPDM rubber in Example 5 is replaced with the modified EPDM rubber prepared in Comparative Example 2 to prepare nylon plastic.

[0052] Comparative Example 5: Nylon plastic was prepared, and the specific steps are as follows:

[0053] The remaining steps remain the same, except that the modified EPDM rubber from Example 5 is removed to prepare nylon plastic.

[0054] Performance testing

[0055] The nylon plastics prepared in Examples 5-7 and Comparative Examples 3-5 were subjected to the following performance tests, and the test results are shown in the table below:

[0056]

[0057] As can be seen from the table above, the nylon plastics prepared in Examples 5-7 of the present invention have better mechanical properties and flame retardant properties, and also have better low-temperature resistance.

[0058] In the description of this specification, the terms "an embodiment," "example," "specific example," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A low-temperature resistant nylon plastic, characterized in that, The raw materials include the following parts by weight: 90-100 parts nylon resin, 20-30 parts modified EPDM rubber, 1-3 parts lubricant, 0.5-1.5 parts antioxidant, and 0.5-1.5 parts ultraviolet absorber; The modified EPDM rubber is prepared through the following steps: Ethylene propylene diene monomer (EPDM) rubber, maleic anhydride, flame retardant, initiator and solvent are stirred and rotary evaporated to obtain a premix. The premix is ​​melt-extruded through a twin-screw extruder, pulverized through a pelletizer and dried to obtain modified EPDM rubber. The ratio of the amount of EPDM rubber, maleic anhydride, flame retardant and initiator is 100g:(0.5-1.5)g:(10-15)g:(0.05-0.15)g; The flame retardant is prepared by the following steps: S1. Purge the flask with nitrogen gas, add 1-tetradecyl alcohol, tetraisopropyl titanate and benzene to the flask, stir and add vinyltrimethoxysilane, heat to 90℃ and react for 24 h, cool and distill under reduced pressure to obtain intermediate 1; the ratio of 1-tetradecyl alcohol, vinyltrimethoxysilane, tetraisopropyl titanate and benzene is 35.2 g: 12.3 mL: 1 mL: 180 mL; S2. Purge the flask with nitrogen gas, add diethyl N,N-bis(2-hydroxyethyl)aminomethylenephosphonate, tetraisopropyl titanate, and dimethyl sulfoxide to the flask, stir, add intermediate 1 and dimethyl sulfoxide, heat to 90℃ and react for 26 h, cool, and distill under reduced pressure to obtain the flame retardant; the ratio of diethyl N,N-bis(2-hydroxyethyl)aminomethylenephosphonate, intermediate 1, tetraisopropyl titanate, and dimethyl sulfoxide is 8.9 g: 38.6 g: 0.44 mL: 200 mL.

2. The low-temperature resistant nylon plastic according to claim 1, characterized in that, The nylon resin is one or more of nylon 6, nylon 66, nylon 610, nylon 612, nylon 1010, and nylon 1212.

3. The low-temperature resistant nylon plastic according to claim 1, characterized in that, The initiator is one or more of benzoyl peroxide, azobisisobutyronitrile, and dicumyl peroxide.

4. The low-temperature resistant nylon plastic according to claim 1, characterized in that, The solvent is one or more of ethanol, acetone, benzene, dimethyl sulfoxide, and N,N-dimethylformamide.

5. The low-temperature resistant nylon plastic according to claim 1, characterized in that, The lubricant is one or more of ethylene bis-stearamide, oleamide, and erucamide.

6. The low-temperature resistant nylon plastic according to claim 1, characterized in that, The antioxidant is one or more of antioxidant 1010, antioxidant 1035, antioxidant 1076, and antioxidant 168.

7. The low-temperature resistant nylon plastic according to claim 1, characterized in that, The ultraviolet absorber is one or more of ultraviolet absorber UV-P, ultraviolet absorber UV-9, ultraviolet absorber UV-531, and ultraviolet absorber UVP-327.

8. The method for preparing a low-temperature resistant nylon plastic according to claim 1, characterized in that, Includes the following steps: The nylon plastic raw materials are mixed evenly in a mixer according to the weight parts, then melt-extruded in a twin-screw extruder, cooled with water, pelletized, and dried to obtain low-temperature resistant nylon plastic.

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