Low-temperature-resistant nylon plastic and preparation method thereof

Abstract

The invention discloses a low-temperature-resistant nylon plastic and a preparation method thereof, and belongs to the technical field of high polymer materials. The preparation method comprises the following steps: uniformly mixing 90-100 parts by weight of nylon resin, 20-30 parts by weight of modified ethylene propylene diene monomer, 1-3 parts by weight of a lubricant, 0.5-1.5 parts by weight of an antioxidant and 0.5-1.5 parts by weight of an ultraviolet light absorber in a stirrer, carrying out melt extrusion in a twin-screw extruder, carrying out water cooling, granulating and drying to obtain the low-temperature-resistant nylon plastic. The maleic anhydride grafted ethylene propylene diene monomer realizes in-situ compatibilization of the modified ethylene propylene diene monomer and the nylon resin; the flame retardant containing a plurality of long carbon chains and the modified ethylene propylene diene monomer have a synergistic effect, so that the nylon plastic is endowed with excellent toughness and low temperature resistance, and in addition, the flame retardant containing nitrogen, phosphorus and silicon halogen-free flame-retardant elements also endows the nylon plastic with efficient, safe, stable and lasting flame-retardant effects. Under the combined action of the other raw materials, the nylon plastic is excellent in comprehensive performance.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a low-temperature resistant nylon plastic and a preparation method thereof. Background Art

[0002] Polyamide (PA), commonly known as nylon, has polar amide groups that can form hydrogen bonds, so it has excellent mechanical properties and impact resistance, and is a relatively tough engineering plastic. This material has the advantages of being non-toxic, odorless, mildew-free, having high surface hardness, wear resistance, self-lubricating, sound-absorbing, chemically stable, and electrically insulating. Due to its excellent properties, nylon is widely used in industrial manufacturing, such as in the fields of automobiles, instruments, machinery, textiles, etc., where this material is mostly used as parts and structural parts.

[0003] However, the flame retardancy of nylon is not very good and it is easy to burn. However, the fields of automobiles, machinery, textiles, etc. all require nylon to have excellent flame retardancy. Among the flame retardant modification methods, the method of adding halogen flame retardants is the most widely used. However, since halogen flame retardants are unstable and produce toxic and harmful substances, the research and development of halogen-free flame retardants is currently the focus of flame retardant direction. In addition, nylon has poor low temperature resistance, which will limit its application range. Therefore, it is urgent to prepare a low temperature resistant nylon plastic with good flame retardancy to meet market demand. Summary of the invention

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

[0005] The purpose of the present 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 of nylon resin, 20-30 parts of modified EPDM rubber, 1-3 parts of lubricant, 0.5-1.5 parts of antioxidant and 0.5-1.5 parts of 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 by the following steps:

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

[0010] EPDM not only has excellent heat resistance, oxygen resistance, weather resistance and aging resistance, but also has good chemical resistance, electrical insulation and low temperature resistance. Therefore, adding modified EPDM as a raw material to nylon plastic can greatly improve the toughness and low temperature resistance of nylon plastic. At the same time, introducing maleic anhydride that can react with the amide group on nylon into the EPDM chain can achieve in-situ capacity expansion, and then the modified EPDM can fully play its role in nylon plastic to enhance the toughness and low temperature resistance of nylon plastic.

[0011] Furthermore, the usage ratio of the 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. A dry three-necked flask was purged with nitrogen for 30 minutes to exclude air and moisture, 1-tetradecanol, tetraisopropyl titanate and benzene were added to the flask, stirred to dissolve, and then vinyltrimethoxysilane was slowly added. After the addition was completed, the temperature was raised to 90°C and reacted for 24 hours. After the reaction was completed, the reaction was cooled to room temperature and distilled under reduced pressure to obtain intermediate 1; the amount ratio of 1-tetradecanol, vinyltrimethoxysilane, tetraisopropyl titanate and benzene was 35.2g:12.3mL:1mL:180mL;

[0014] Under the catalytic action of tetraisopropyl titanate, the molar ratio of 1-tetradecanol and vinyltrimethoxysilane is controlled to be 2.0-2.1:1, and the hydroxyl group of 1-tetradecanol and the silane group of vinyltrimethoxysilane undergo the following chemical reaction, and the reaction process is as follows:

[0015]

[0016] S2. Blow nitrogen gas into a dry three-necked flask for 30 minutes to exclude air and moisture, add diethyl N,N-bis(2-hydroxyethyl)aminomethylenephosphonate, tetraisopropyl titanate and dimethyl sulfoxide into the flask, stir to dissolve, then slowly add a mixed solution of intermediate 1 and dimethyl sulfoxide, raise the temperature to 90°C after the addition is complete, react for 26 hours, cool to room temperature after the reaction is completed, and distill under reduced pressure to obtain a flame retardant; the amount ratio of diethyl N,N-bis(2-hydroxyethyl)aminomethylenephosphonate, intermediate 1, tetraisopropyl titanate and dimethyl sulfoxide is 8.9g:38.6g:0.44mL:200mL.

[0017] The molar ratio of N,N-bis(2-hydroxyethyl)aminomethylenephosphonic acid diethyl ester to intermediate 1 is controlled to be 1:2.1-2.2, and the hydroxyl group of N,N-bis(2-hydroxyethyl)aminomethylenephosphonic acid diethyl ester and the silaneoxy group of intermediate 1 undergo the following chemical reaction under the catalysis of tetraisopropyl titanate. The reaction process is 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 the EPDM rubber under the action of the initiator, and then the flame retardant is grafted onto the EPDM rubber and firmly exists in the modified EPDM rubber, so that the multiple long carbon chains in the flame retardant can increase the flexibility of the EPDM rubber molecular chain segments, and the glass transition temperature is significantly reduced. In addition, due to the synergistic effect of the EPDM rubber, the modified EPDM rubber of the present invention is more resistant to low temperatures, and thus the nylon plastic of the present invention is also more resistant to low temperatures; the long carbon chains that can be freely extended and rotated can also improve the mechanical properties such as toughness and tensile strength of the modified EPDM rubber, and thus improve the mechanical properties such as toughness and tensile strength of the nylon plastic. In addition, the flame retardant achieves the purpose of high flame retardancy, low smoke emission, and low harmfulness through the synergistic effect of nitrogen, phosphorus, and silicon halogen-free flame retardant elements, and thus the nylon plastic of the present invention has 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 bisstearamide, 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 comprises the following steps:

[0026] The raw materials of nylon plastic are mixed uniformly in a mixer according to weight, and then melt-extruded in a twin-screw extruder, and pelletized and dried through water cooling to obtain low-temperature resistant nylon plastic.

[0027] The beneficial effects of the present invention are as follows: maleic anhydride grafted EPDM rubber realizes in-situ volume expansion of modified EPDM rubber and nylon resin; the flame retardant containing multiple long carbon chains and the modified EPDM rubber synergistically endow the nylon plastic with excellent toughness and low temperature resistance; in addition, the flame retardant containing nitrogen, phosphorus, and silicon halogen-free flame retardant elements also endows the nylon plastic with efficient, safe, stable and long-lasting flame retardant effect. In addition to the joint effect of the other raw materials, the nylon plastic of the present invention has excellent comprehensive performance. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1, preparing a flame retardant, the specific steps are as follows:

[0030] S1. A 500 mL dry three-necked flask was purged with nitrogen for 30 min to exclude air and moisture, 35.2 g of 1-tetradecanol, 1 mL of tetraisopropyl titanate and 180 mL of benzene were added to the flask, stirred to dissolve, and then 12.3 mL of vinyltrimethoxysilane was slowly added. After the addition was completed, the temperature was raised to 90 ° C and reacted for 24 h. After the reaction was completed, it was cooled to room temperature and distilled under reduced pressure to obtain intermediate 1;

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

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

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

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

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

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

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

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

[0039] 45 parts of nylon 1010, 45 parts of nylon 1212, 20 parts of modified EPDM rubber prepared in Example 4, 1 part of ethylene bisstearamide, 0.5 parts of antioxidant 1010, and 0.5 parts of ultraviolet absorber UV-P are mixed uniformly in a blender by weight, then melt-extruded in a twin-screw extruder, pelletized after water cooling, and dried to obtain nylon plastic.

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

[0041] 98 parts of nylon 612, 26 parts of modified EPDM rubber prepared in Example 3, 1 part of oleic acid amide, 1 part of erucic acid amide, 0.6 parts of antioxidant 1035, 0.4 parts of antioxidant 1076, 0.5 parts of ultraviolet absorber UV-9 and 0.5 parts of ultraviolet absorber UV-531 were mixed uniformly in a blender by weight, then melt-extruded in a twin-screw extruder, pelletized after water cooling and dried to obtain nylon plastic.

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

[0043] 80 parts of nylon 6, 20 parts of nylon 66, 30 parts of modified EPDM rubber prepared in Example 2, 1 part of ethylene bisstearamide, 1 part of oleic acid amide, 1 part of erucic acid amide, 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 are mixed uniformly in a blender by weight, then melt-extruded in a twin-screw extruder, pelletized after water cooling, and dried to obtain a low-temperature resistant nylon plastic.

[0044] Comparative Example 1, preparing modified EPDM rubber, the specific steps are as follows:

[0045] The remaining steps remain unchanged, only the flame retardant in Example 4 is removed to prepare the modified EPDM rubber.

[0046] Comparative Example 2, preparing modified EPDM rubber, the specific steps are as follows:

[0047] The remaining steps remained unchanged, except that the flame retardant in Example 4 was replaced by 15 g of ammonium polyphosphate to prepare modified EPDM rubber.

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

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

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

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

[0052] Comparative Example 5, preparing nylon plastic, the specific steps are as follows:

[0053] The remaining steps remain unchanged, only the modified EPDM rubber of Example 5 is removed to prepare the 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 following table:

[0056]

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

[0058] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0059] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A low temperature resistant nylon plastic, characterized in that: The method comprises the following raw materials in parts by weight: 90-100 parts of nylon resin, 20-30 parts of modified EPDM rubber, 1-3 parts of lubricant, 0.5-1.5 parts of antioxidant, and 0.5-1.5 parts of ultraviolet absorber; Wherein, the modified EPDM rubber is prepared by the following steps: 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, crushed through a pelletizer, and dried to obtain a modified EPDM rubber; The usage ratio of the 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. The flask was purged with nitrogen, 1-tetradecanol, tetraisopropyl titanate and benzene were added to the flask, and vinyltrimethoxysilane was added after stirring. The temperature was raised to 90°C for reaction for 24 hours, cooled, and distilled under reduced pressure to obtain intermediate 1; the amount ratio of 1-tetradecanol, vinyltrimethoxysilane, tetraisopropyl titanate and benzene was 35.2 g: 12.3 mL: 1 mL: 180 mL; S2. Blow nitrogen into the flask, add diethyl N,N-bis(2-hydroxyethyl)aminomethylenephosphonate, tetraisopropyl titanate and dimethyl sulfoxide into the flask, stir and add intermediate 1 and dimethyl sulfoxide, heat to 90°C and react for 26 hours, cool and distill under reduced pressure to obtain a flame retardant; the dosage 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 bisstearamide, 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 the ultraviolet absorber UV-P, ultraviolet absorber UV-9, ultraviolet absorber UV-531, and ultraviolet absorber UVP-327.

8. The method for preparing low temperature resistant nylon plastic according to claim 1, characterized in that: The following steps are involved: The raw materials of nylon plastic are mixed uniformly in a mixer according to weight, and then melt-extruded in a twin-screw extruder, and pelletized and dried through water cooling to obtain low-temperature resistant nylon plastic.

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