Nylon 6 for high-strength transparent monofilament and preparation method thereof

Abstract

The invention relates to the technical field of nylon 6, in particular to nylon 6 for high-strength transparent monofilaments and a preparation method of the nylon 6. The nylon 6 for the high-strength transparent monofilament is prepared from the following raw materials in parts by mass: 80 to 100 parts of caprolactam, 1 to 5 parts of graphene oxide, 1 to 2 parts of amino-terminated polyamidoamine, 0.01 to 0.1 part of ethylenediamine, 1 to 5 parts of nano silicon dioxide, 1 to 2 parts of nucleating agent, 1 to 2 parts of surfactant, 1 to 2 parts of coupling agent, 1 to 3 parts of antioxidant and 1 to 2 parts of antistatic agent. The preparation method disclosed by the invention is simple and effective, and the obtained nylon 6 material not only has very good transparency and glossiness, but also has very good heat resistance and mechanical strength, and also has very good toughness and fracture resistance under a high-temperature condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nylon 6, and particularly relates to a high-strength transparent monofilament nylon 6 and a preparation method thereof. BACKGROUND

[0002] As a material with excellent performance, polyamide is widely used in many fields such as automobiles, machinery, electronics, communications and home appliances due to its excellent mechanical properties, electrical properties, processing properties and chemical stability. It has good tensile strength, compression strength, impact strength, rigidity and wear resistance, good electrical insulation under low temperature and dry conditions, extremely low thermal conductivity, high chemical stability, good stability to salt water, bacteria and mold, and is odorless, tasteless, non-toxic and self-extinguishing.

[0003] However, there are still many problems in the practical application of nylon 6 material. The existing nylon 6 material has poor transparency, which limits its application in optical devices, packaging materials and other fields that require high transparency. At the same time, the nylon 6 material has insufficient heat resistance and is prone to deformation and performance degradation under high temperature environment, which is difficult to meet the use requirements of some high temperature working conditions. When the nylon 6 material is subjected to impact or external force, it is prone to brittle fracture, affecting the service life and reliability of the material.

[0004] At present, these problems to some extent restrict the application expansion of nylon 6 material. Therefore, how to effectively improve the transparency, heat resistance and toughness of nylon 6 material has become a technical problem to be solved at present. SUMMARY

[0005] The present application aims to solve the problems in the prior art and provides a high-strength transparent monofilament nylon 6 and a preparation method thereof.

[0006] A high-strength transparent monofilament nylon 6, the raw materials of which include, by mass fraction: caprolactam 80-100 parts, graphene oxide 1-5 parts, terminal amino polyamide amine 1-2 parts, ethylenediamine 0.01-0.1 parts, nano silicon dioxide 1-5 parts, nucleating agent 1-2 parts, surfactant 1-2 parts, coupling agent 1-2 parts, antioxidant 1-3 parts, and antistatic agent 1-2 parts.

[0007] Preferably, the number of generations of the terminal amino polyamide amine is 2.0-4.0 generations.

[0008] Preferably, the nucleating agent is N,N',N''-tricyclohexyl-1,3,5-benzamide, ethylene bis-stearamide or / and talc.

[0009] Preferably, the surfactant is stearic acid.

[0010] Preferably, the coupling agent is KH-570 coupling agent.

[0011] Preferably, the antioxidant is antioxidant 1076 or / and antioxidant 1010.

[0012] Preferably, the antistatic agent is at least one of fatty amine polyoxyethylene ether, octadecyltrimethylammonium chloride, and dodecyldimethylbetaine.

[0013] The preparation method of the above-mentioned high-strength transparent monofilament nylon 6 includes the following steps: S1. Add graphene oxide to an ethanol aqueous solution and sonicate for 1-2 hours. Add terminal amino polyamide amine and ethylenediamine to the solution. Stir at 80-90°C for 5-10 hours under nitrogen protection. Filter, wash, and vacuum dry to obtain the pretreated material. S2. Add the pretreated material and water to the caprolactam melt, stir evenly at 90-95℃, react the dispersion at 250-280℃ for 2-5 hours under nitrogen protection, adjust the vacuum degree to -0.05~-0.09MPa, continue to react for 2-5 hours, cool with water, and granulate to obtain the base material; S3. After drying the base material, add nano silica, nucleating agent, surfactant, coupling agent, antioxidant, and antistatic agent, mix evenly, melt extrude, granulate, cool, and dry.

[0014] Preferably, in S2, during the reaction at 250-280℃ under nitrogen protection, the reaction pressure is 1.5-2MPa.

[0015] Preferably, in S3, a twin-screw extruder is used for melt extrusion, the extruder barrel temperature is 230-250℃, and the main screw speed is 150-300r / min.

[0016] Beneficial effects: This invention grafts terminal amino-terminated polyamide amines onto graphene oxide, which significantly enhances the interfacial bonding force with the nylon 6 matrix, effectively prevents graphene agglomeration, and can still be uniformly dispersed even at high addition levels, thereby fully exerting the reinforcing effect.

[0017] This invention utilizes the good compatibility and dispersion of grafted graphene oxide and nano-silica in the matrix, which reduces light scattering and jointly ensures that the product has high light transmittance and low haze, achieving excellent transparency and gloss. At the same time, the two-dimensional sheet structure of graphene forms a strong interfacial bond with the matrix, which improves the stress transmission of the composite material and significantly improves the tensile strength, flexural strength and heat resistance of the material, enabling it to maintain good mechanical properties under high temperature conditions. The introduction of nano-silica further synergistically enhances the rigidity and thermal stability of the material.

[0018] The preparation method of this invention is simple and effective. The resulting nylon 6 material not only has excellent transparency and gloss, but also has excellent heat resistance and mechanical strength. Under high temperature conditions, it also has excellent toughness and fracture resistance. Attached Figure Description

[0019] Figure 1 The diagram shows a comparison of the tensile strength and flexural strength of the nylon 6 materials obtained in Example 5 and Comparative Examples 1-2.

[0020] Figure 2 The image shows a comparison of the gloss and light transmittance of the nylon 6 materials obtained in Example 5 and Comparative Examples 1-2.

[0021] Figure 3 The graph shows a comparison of the notched impact strength and thermal decomposition temperature of the nylon 6 materials obtained in Example 5 and Comparative Examples 1-2. Detailed Implementation

[0022] The present invention will be further explained below with reference to specific embodiments.

[0023] The amino-terminated polyamide amine (PAMAM, G3.0) used below was purchased from Xi'an Kaixin Biotechnology Co., Ltd., with ethylenediamine as the core. Graphene oxide was purchased from Hebei Ruihuang Metal Materials Co., Ltd., with a particle size of 75±25nm.

[0024] Example 1 A high-strength transparent monofilament nylon 6, the raw materials of which include: 800g caprolactam, 10g graphene oxide, 10g amino-terminated polyamide amine, 0.1g ethylenediamine, 10g nano silica, 10g talc, 10g stearic acid, 10g KH-570 coupling agent, 10g antioxidant 1010, and 10g fatty amine polyoxyethylene ether.

[0025] The preparation method of the above-mentioned high-strength transparent monofilament nylon 6 includes the following steps: S1. Add graphene oxide to 400g of 40% ethanol aqueous solution and sonicate for 1h. Add terminal amino polyamide amine and ethylenediamine to the solution. Stir at 80℃ for 5h under nitrogen protection. Filter, wash and vacuum dry to obtain pretreated material. S2. Add the pretreated material and 10g of deionized water to the caprolactam melt, stir evenly at 90℃ and 300r / min, add the dispersion to the reactor, react at 250℃ for 2h under nitrogen protection and 1.5MPa, continue to react at -0.05MPa vacuum for 2h, cool with water, granulate to obtain the base material; S3. Dry the base material at 100℃, add nano silica, talc, stearic acid, KH-570 coupling agent, antioxidant 1010, and fatty amine polyoxyethylene ether and mix evenly. Add the mixture to the extruder and melt-extrude it through a twin-screw extruder. The extruder barrel temperature is 230℃ and the main screw speed is 150r / min. Under the traction of the traction machine, the strip is fed into the pelletizer for pelletizing, cooling, and drying.

[0026] Example 2 A high-strength transparent monofilament nylon 6, the raw materials of which include: 1000g caprolactam, 50g graphene oxide, 20g amino-terminated polyamide amine, 1g ethylenediamine, 50g nano silica, 20g talc, 20g stearic acid, 20g KH-570 coupling agent, 30g antioxidant 1076, and 20g fatty amine polyoxyethylene ether.

[0027] The preparation method of the above-mentioned high-strength transparent monofilament nylon 6 includes the following steps: S1. Add graphene oxide to 600g of 60% ethanol aqueous solution and sonicate for 2h. Add terminal amino polyamide amine and ethylenediamine to it. Stir at 90℃ for 10h under nitrogen protection. Filter, wash and vacuum dry to obtain pretreated material. S2. Add the pretreated material and 20g of deionized water to the caprolactam melt, stir evenly at 95℃ and 400r / min, add the dispersion to the reactor, react at 280℃ for 5h under nitrogen protection and 2MPa reaction pressure, continue to react at -0.09MPa vacuum for 5h, cool with water, granulate to obtain the base material; S3. Dry the base material at 100℃, add nano silica, talc, stearic acid, KH-570 coupling agent, antioxidant 1076, and fatty amine polyoxyethylene ether and mix evenly. Add the mixture to the extruder and melt-extrude it through a twin-screw extruder. The extruder barrel temperature is 250℃ and the main screw speed is 300r / min. Under the traction of the traction machine, the strip is fed into the pelletizer for pelletizing, cooling, and drying.

[0028] Example 3 A high-strength transparent monofilament nylon 6, the raw materials of which include: 850g caprolactam, 40g graphene oxide, 12g amino-terminated polyamide amine, 0.7g ethylenediamine, 20g nano silica, 18g N,N',N''-tricyclohexyl-1,3,5-benzamide, 13g stearic acid, 17g KH-570 coupling agent, 15g antioxidant 1010, and 15g dodecyl dimethyl betaine.

[0029] The preparation method of the above-mentioned high-strength transparent monofilament nylon 6 includes the following steps: S1. Add graphene oxide to 550g of 45% ethanol aqueous solution and sonicate for 100min. Add terminal amino polyamide amine and ethylenediamine to the solution. Stir at 82℃ for 9h under nitrogen protection. Filter, wash and vacuum dry to obtain pretreated material. S2. Add the pretreated material and 15g of deionized water to the caprolactam melt, stir evenly at 91℃ and 370r / min, add the dispersion to the reactor, react at 260℃ for 4h under nitrogen protection and 1.7MPa reaction pressure, continue to react at -0.08MPa vacuum for 3h, cool with water, granulate to obtain the base material; S3. Dry the base material at 100℃, add nano silica, N,N',N''-tricyclohexyl-1,3,5-benzamide, stearic acid, KH-570 coupling agent, antioxidant 1010, and dodecyl dimethyl betaine, mix evenly, add to the extruder, and melt extrude through a twin-screw extruder. The extruder barrel temperature is 245℃, and the main screw speed is 200r / min. Under the traction of the traction machine, the strip is fed into the pelletizer for pelleting, cooling, and drying.

[0030] Example 4 A high-strength transparent monofilament nylon 6, the raw materials of which include: 950g caprolactam, 20g graphene oxide, 18g amino-terminated polyamide amine, 0.3g ethylenediamine, 40g nano silica, 12g N,N',N''-tricyclohexyl-1,3,5-benzamide, 17g stearic acid, 13g KH-570 coupling agent, 25g antioxidant 1076, and 15g dodecyl dimethyl betaine.

[0031] The preparation method of the above-mentioned high-strength transparent monofilament nylon 6 includes the following steps: S1. Add graphene oxide to 450g of 55% ethanol aqueous solution and sonicate for 80min. Add terminal amino polyamide amine and ethylenediamine to the solution. Stir at 88℃ for 7h under nitrogen protection. Filter, wash and vacuum dry to obtain pretreated material. S2. Add the pretreated material and 15g of deionized water to the caprolactam melt, stir evenly at 93℃ and 330r / min, add the dispersion to the reactor, react at 270℃ for 3h under nitrogen protection and 1.9MPa reaction pressure, continue to react at -0.06MPa vacuum for 4h, cool with water, granulate to obtain the base material; S3. Dry the base material at 100℃, add nano silica, N,N',N''-tricyclohexyl-1,3,5-benzamide, stearic acid, KH-570 coupling agent, antioxidant 1076, and dodecyl dimethyl betaine, mix evenly, add to the extruder, and melt extrude through a twin-screw extruder. The extruder barrel temperature is 235℃, and the main screw speed is 240r / min. Under the traction of the traction machine, the strip is fed into the pelletizer for pelleting, cooling, and drying.

[0032] Example 5 A high-strength transparent monofilament nylon 6, the raw materials of which include: 900g caprolactam, 30g graphene oxide, 15g amino-terminated polyamide amine, 0.5g ethylenediamine, 30g nano silica, 15g ethylene bis-stearamide, 15g stearic acid, 15g KH-570 coupling agent, 20g antioxidant 1010, and 15g octadecyltrimethylammonium chloride.

[0033] The preparation method of the above-mentioned high-strength transparent monofilament nylon 6 includes the following steps: S1. Add graphene oxide to 500g of 50% ethanol aqueous solution and sonicate for 90min. Add terminal amino polyamide amine and ethylenediamine to the solution. Stir at 85℃ for 8h under nitrogen protection. Filter, wash and vacuum dry to obtain pretreated material. S2. Add the pretreated material and 15g of deionized water to the caprolactam melt, stir evenly at 92℃ and 350r / min, add the dispersion to the reactor, react at 265℃ for 3.5h under nitrogen protection and 1.8MPa, continue to react at -0.07MPa for 3.5h, cool with water, granulate to obtain the base material; S3. Dry the base material at 100℃, add nano silica, ethylene bis-stearamide, stearic acid, KH-570 coupling agent, antioxidant 1010, and octadecyltrimethylammonium chloride and mix evenly. Add the mixture to the extruder and melt-extrude it through a twin-screw extruder. The extruder barrel temperature is 240℃ and the main screw speed is 220r / min. Under the traction of the traction machine, the strip is fed into the pelletizer for pelletizing, cooling, and drying.

[0034] Comparative Example 1 A high-strength transparent monofilament nylon 6, the raw materials of which include: 900g caprolactam, 30g graphene oxide, 15g amino-terminated polyamide amine, 30g nano silica, 15g ethylene bis-stearamide, 15g stearic acid, 15g KH-570 coupling agent, 20g antioxidant 1010, and 15g octadecyltrimethylammonium chloride.

[0035] The preparation method of the above-mentioned high-strength transparent monofilament nylon 6 includes the following steps: S1. Add graphene oxide, amino-terminated polyamide amine and 15g of deionized water to caprolactam melt, stir evenly at 92℃ and 350r / min, add the dispersion to the reactor, react at 265℃ for 3.5h under nitrogen protection and reaction pressure of 1.8MPa, continue to react at vacuum degree -0.07MPa for 3.5h, cool with water, granulate to obtain the base material; S2. Dry the base material at 100℃, add nano silica, ethylene bis-stearamide, stearic acid, KH-570 coupling agent, antioxidant 1010, and octadecyltrimethylammonium chloride and mix evenly. Add the mixture to the extruder and melt-extrude it through a twin-screw extruder. The extruder barrel temperature is 240℃ and the main screw speed is 220r / min. Under the traction of the traction machine, the strip is fed into the pelletizer for pelletizing, cooling, and drying.

[0036] Comparative Example 2 A high-strength transparent monofilament nylon 6, the raw materials of which include: 900g caprolactam, 30g graphene oxide, 15g amino-terminated polyamide amine, 0.5g ethylenediamine, 30g nano silica, 15g ethylene bis-stearamide, 15g stearic acid, 15g KH-570 coupling agent, 20g antioxidant 1010, and 15g octadecyltrimethylammonium chloride.

[0037] The preparation method of the above-mentioned high-strength transparent monofilament nylon 6 includes the following steps: S1. Add graphene oxide to 500g of 50% ethanol aqueous solution and sonicate for 90min. Add terminal amino polyamide amine and ethylenediamine to the solution. Stir at 85℃ for 8h under nitrogen protection. Filter, wash and vacuum dry to obtain pretreated material. S2. Add 15g of deionized water to the caprolactam melt and stir evenly at 92℃ and 350r / min. Add the dispersion to the reactor and react at 265℃ for 3.5h under nitrogen protection and 1.8MPa. Continue to react at -0.07MPa vacuum for 3.5h, cool with water, granulate, and obtain the base material. S3. Dry the base material at 100℃, add the pretreated material and nano silica, ethylene bis-stearamide, stearic acid, KH-570 coupling agent, antioxidant 1010, and octadecyltrimethylammonium chloride and mix evenly. Add the mixture to the extruder and melt-extrude it through a twin-screw extruder. The extruder barrel temperature is 240℃ and the main screw speed is 220r / min. Under the traction of the traction machine, the strip is fed into the pelletizer for pelletizing, cooling, and drying.

[0038] The spinnability (melt spinning / electrospinning) of the nylon 6 materials obtained in Example 5 and Comparative Examples 1-2 was tested. The results showed that the nylon 6 material obtained in Example 5 was easy to spin, while the nylon 6 material obtained in Comparative Example 1 was difficult to spin. The nylon 6 material obtained in Comparative Example 2 was more difficult to spin than that of Example 5 but less difficult than that of Comparative Example 1.

[0039] The tensile strength of the nylon 6 materials obtained in Example 5 and Comparative Examples 1-2 was determined according to ASTM D638 at a tensile speed of 5 mm / min. The flexural strength of the nylon 6 materials obtained in Example 5 and Comparative Examples 1-2 was determined according to GB / T 9341-2008 "Determination of Flexural Properties of Plastics".

[0040] like Figure 1 As shown, the nylon 6 material obtained in Example 5 has the highest tensile strength and flexural strength, which are significantly better than those of the comparative example.

[0041] The gloss of the nylon 6 materials obtained in Example 5 and Comparative Examples 1-2 was determined according to ASTM D2457 at an incident angle of 60°. The light transmittance of the nylon 6 materials obtained in Example 5 and Comparative Examples 1-2 was determined according to ASTM D1003.

[0042] like Figure 2 As shown, the nylon 6 material obtained in Example 5 has the highest gloss and light transmittance, which are significantly better than the comparative example.

[0043] The cantilever beam notched impact strength of the nylon 6 materials obtained in Example 5 and Comparative Examples 1-2 was determined according to ASTM D256. The test specimens were 127mm × 13mm × 3.2mm in size, with a V-notch and a notch depth of 1 / 5.

[0044] Take 5 mg of Nylon 6 material obtained in Example 5 and Comparative Examples 1-2, and perform thermal performance tests in a thermogravimetric analyzer. Nitrogen is used as the test atmosphere, the heating rate is 10℃ / min, and the mass loss is 5%.

[0045] like Figure 3 As shown, the notched impact strength and thermal decomposition temperature of the nylon 6 material obtained in Example 5 are the highest, which are significantly better than those of the comparative example.

[0046] The reason for the above results is that this invention grafts terminal amino-terminated polyamide amine onto graphene oxide, significantly enhancing the interfacial bonding force with the nylon 6 matrix, effectively preventing graphene aggregation, and ensuring uniform dispersion even at high addition levels, thus fully leveraging the reinforcing effect. This invention utilizes the good compatibility and dispersion of grafted graphene oxide and nano-silica within the matrix, reducing light scattering and jointly ensuring high light transmittance and low haze, achieving excellent transparency and gloss. Simultaneously, the two-dimensional sheet structure of graphene forms a strong interfacial bond with the matrix, improving stress transmission in the composite material and significantly enhancing its tensile strength, flexural strength, and heat resistance, allowing it to maintain good mechanical properties even at high temperatures. Furthermore, the introduction of nano-silica further synergistically enhances the material's rigidity and thermal stability.

[0047] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-strength transparent nylon 6 monofilament, characterized by, The raw materials include, by mass fraction: caprolactam 80-100 parts, graphene oxide 1-5 parts, terminal amino polyamide amine 1-2 parts, ethylenediamine 0.01-0.1 parts, nano silicon dioxide 1-5 parts, nucleating agent 1-2 parts, surfactant 1-2 parts, coupling agent 1-2 parts, antioxidant 1-3 parts, antistatic agent 1-2 parts.

2. The nylon 6 for high-strength transparent monofilaments according to claim 1, characterized by The number of generations of the terminal amino polyamide amine is 2.0-4.0 generations.

3. The nylon 6 for high-strength transparent monofilaments according to claim 1, characterized by, The nucleating agent is N,N',N''-tricyclohexyl-1,3,5-benzamide, ethylene bis-stearamide or / and talc.

4. The nylon 6 for high-strength transparent monofilaments according to claim 1, characterized by, The surfactant is stearic acid.

5. The nylon 6 for high-strength transparent monofilaments according to claim 1, wherein The coupling agent is KH-570 coupling agent.

6. The nylon 6 for high-strength transparent monofilaments according to claim 1, wherein The antioxidant is antioxidant 1076 or / and antioxidant 1010.

7. The nylon 6 for high-strength transparent monofilaments according to claim 1, wherein The antistatic agent is at least one of fatty amine polyoxyethylene ether, octadecyl trimethyl ammonium chloride and dodecyl dimethyl betaine.

8. A process for the production of nylon 6 for high-strength transparent monofilaments as claimed in any one of claims 1 to 7, characterized in that, The method comprises the following steps: S1, graphene oxide is added to an ethanol aqueous solution and ultrasonically treated for 1-2 hours, terminal amino polyamide amine and ethylenediamine are added thereto, and stirring is performed at 80-90°C under nitrogen protection for 5-10 hours, then filtration, washing and vacuum drying are performed to obtain pretreated material; S2, the pretreated material and water are added to a caprolactam melt, and stirring is performed uniformly at 90-95°C, then the dispersion is reacted at 250-280°C under nitrogen protection for 2-5 hours, the vacuum degree is adjusted to -0.05 to -0.09 MPa, and the reaction is continuously performed for 2-5 hours, then water cooling and granulation are performed to obtain a base material; S3, after the base material is dried, nano silicon dioxide, a nucleating agent, a surfactant, a coupling agent, an antioxidant and an antistatic agent are added and uniformly mixed, and then melt extrusion, granulation, cooling and drying are performed.

9. The method for preparing high-strength transparent monofilament nylon 6 according to claim 8, characterized in that, In S2, during the reaction at 250-280°C under nitrogen protection, the reaction pressure is 1.5-2 MPa.

10. The method for preparing high-strength transparent monofilament nylon 6 according to claim 8, characterized in that, In S3, melt extrusion is performed by using a double-screw extruder, the barrel temperature of the extruder is 230-250°C, and the main machine screw rotation speed is 150-300 r / min.

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