Graphene composite modified flame-retardant nylon plastic

Abstract

The invention relates to a graphene composite modified flame-retardant nylon plastic, and belongs to the technical field of composite materials. The reactive flame retardant with carboxyl and amino in the structure is prepared, the flame retardant can react with nylon resin and is directly bonded to a nylon resin molecular chain through a covalent bond, the compatibility of the flame retardant and a nylon resin matrix is effectively improved, and the migration problem of the flame retardant is solved; in addition, the reactive flame retardant also has a quaternary ammonium salt structure, a charged quaternary ammonium salt structure can be introduced into a nylon resin structure, dispersion of graphene is promoted by means of ion-dipole interaction with carboxyl on the surface of graphene, the dispersion state of graphene is anchored, migration of graphene in the use process is inhibited, and the flame retardant property is improved. Under the interface interaction, the graphene can form a more continuous conductive / thermal network in the nylon matrix, and the modification effect of the graphene on the nylon resin matrix is effectively enhanced.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a graphene-modified flame-retardant nylon plastic. Background Technology

[0002] Polyamide (PA), or nylon, is the world's first completely man-made synthetic fiber. It has excellent mechanical strength, abrasion resistance, chemical resistance, and self-lubricating properties, and is widely used in automotive parts, electronics, and machinery. However, nylon plastic is a flammable material with a low limiting oxygen index (LOI). To overcome the flame retardancy of nylon plastic, flame retardants are usually added during the preparation process. However, flame retardants have poor compatibility with nylon plastic and are prone to phase separation in nylon plastic. Adding a large amount of flame retardant will lead to a serious decline in the mechanical properties of nylon plastic.

[0003] Modifying nylon plastic with graphene can not only improve its electrical and thermal conductivity, but also promote the char formation of flame retardants and enhance the strength and density of the char layer, effectively improving the effect of flame retardants and reducing the amount of flame retardants used. Based on this, the present invention provides a graphene composite modified flame retardant nylon plastic. Summary of the Invention

[0004] The purpose of this invention is to provide a graphene-modified flame-retardant nylon plastic to solve the problems mentioned in the background art.

[0005] The objective of this invention can be achieved through the following technical solutions: A graphene-modified flame-retardant nylon plastic comprises the following raw materials in parts by weight: 100 parts nylon resin, 1.8 to 2.2 parts graphene, 8 to 10 parts reactive flame retardant, and 0.2 to 0.4 parts antioxidant.

[0006] The reactive flame retardant of the present invention has carboxyl and amino groups in its structure.

[0007] Preferably, the reactive flame retardant can be prepared by the following method: An intermediate is obtained by Michael addition reaction of unsaturated carboxylic acids with organophosphorus compounds, and then the intermediate is reacted with aliphatic amines to produce a reactive flame retardant.

[0008] Preferably, the unsaturated carboxylic acid is at least one of 4-chloro-2-butenoic acid and 4-bromobutenoic acid.

[0009] Preferably, the organophosphorus compound contains at least one phosphonate group in its structure.

[0010] Preferably, the fatty amine is at least one of N,N-dimethylethylenediamine and N,N-diethylethylenediamine.

[0011] Preferably, the nylon resin is at least one of nylon 6 and nylon 66.

[0012] Preferably, the graphene is reduced graphene oxide.

[0013] Preferably, the antioxidant is at least one of antioxidant 1010, antioxidant 1035, and antioxidant 168.

[0014] Preferably, the graphene-modified flame-retardant nylon plastic is prepared by melt extrusion of various raw materials.

[0015] The beneficial effects of this invention are: This invention prepares a reactive flame retardant with carboxyl and amino groups in its structure. This flame retardant can react with nylon resin and directly bind to the nylon resin molecular chain through covalent bonds, effectively improving the compatibility between the flame retardant and the nylon resin matrix and solving the migration problem of the flame retardant. The reactive flame retardant of this invention has less impact on the mechanical properties of the nylon resin matrix, and the finished plastic has better mechanical properties and higher thermal stability.

[0016] The reactive flame retardant of the present invention has a quaternary ammonium salt structure. After reacting with the nylon resin molecular chain, it can introduce a charged quaternary ammonium salt structure into the nylon resin structure, accelerate the leakage of static charge, and improve the antistatic properties of nylon plastic.

[0017] The nylon resin molecular chain of the present invention has a positively charged quaternary ammonium salt structure, which can promote the dispersion of graphene by generating ion-dipole interactions with the carboxyl groups on the surface of graphene, and anchor the dispersed state of graphene, inhibiting the migration of graphene during use. Under this interfacial interaction, graphene can form a more continuous conductive / thermal network in the nylon matrix, effectively enhancing the modification effect of graphene on the nylon resin matrix.

[0018] This invention utilizes ion-dipole interactions to effectively promote the mutual attraction between graphene and flame retardants, thereby enhancing the synergistic flame-retardant effect between the two. Detailed Implementation

[0019] The technical solution 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.

[0020] The raw materials used in this invention are not particularly restricted in terms of their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0021] Example 1 A graphene-modified flame-retardant nylon plastic comprises the following raw materials in parts by weight: 100 parts nylon 6 resin, 1.8 parts reduced graphene oxide, 10 parts reactive flame retardant, and 0.2 parts antioxidant 1010. The reactive flame retardant is prepared by the following method: S1. 0.1 mol 4-chloro-2-butenoic acid, 0.12 mol diethyl phosphite, 0.01 mol 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 60 mL tetrahydrofuran were mixed in a three-necked flask equipped with a thermometer and a reflux condenser. The mixture was reacted at 40 °C for 3 h. The reaction solution was then evaporated to dryness. The remaining solid was washed with cold deionized water and dried to obtain an intermediate. S2. Mix 0.08 mol of intermediate, 0.1 mol of N,N-dimethylethylenediamine and 60 mL of N,N-dimethylformamide in a three-necked flask equipped with a thermometer and a reflux condenser. React at 35°C for 24 h. After the reaction is complete, evaporate the reaction solution to dryness to obtain a reactive flame retardant. The graphene-modified flame-retardant nylon plastic was prepared by melt extrusion of various raw materials in a twin-screw extruder at a temperature of 275℃.

[0022] Example 2 A graphene-modified flame-retardant nylon plastic comprises the following raw materials in parts by weight: 100 parts nylon 66 resin, 2 parts reduced graphene oxide, 9 parts reactive flame retardant, 0.2 parts antioxidant 1010, and 0.1 parts antioxidant 168. The reactive flame retardant is prepared by the following method: S1. 0.1 mol 4-chloro-2-butenoic acid, 0.13 mol dimethyl phosphite, 0.01 mol 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 70 mL tetrahydrofuran were mixed in a three-necked flask equipped with a thermometer and a reflux condenser. The mixture was reacted at 50 °C for 2.5 h. The reaction solution was then evaporated to dryness. The remaining solid was washed with cold deionized water and dried to obtain an intermediate. S2. Mix 0.08 mol of intermediate, 0.11 mol of N,N-dimethylethylenediamine, and 70 mL of N,N-dimethylformamide in a three-necked flask equipped with a thermometer and a reflux condenser. React at 55 °C for 10 h. After the reaction is complete, evaporate the reaction solution to dryness to obtain a reactive flame retardant. The graphene-modified flame-retardant nylon plastic was prepared by melt extrusion of various raw materials in a twin-screw extruder at a temperature of 280℃.

[0023] Example 3 A graphene-modified flame-retardant nylon plastic comprises the following raw materials in parts by weight: 100 parts nylon 66 resin, 2.2 parts reduced graphene oxide, 8 parts reactive flame retardant, 0.3 parts antioxidant 1035, and 0.1 parts antioxidant 168. The reactive flame retardant is prepared by the following method: S1. 0.1 mol 4-bromobut-2-enoic acid, 0.15 mol diphenyl phosphite, 0.01 mol 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 80 mL tetrahydrofuran were mixed in a three-necked flask equipped with a thermometer and a reflux condenser. The mixture was reacted at 60 °C for 2 h. The reaction solution was then evaporated to dryness, and the remaining solid was eluted by silica gel column chromatography to obtain an intermediate. S2. Mix 0.08 mol of intermediate, 0.12 mol of N,N-diethylethylenediamine, and 80 mL of N,N-dimethylformamide in a three-necked flask equipped with a thermometer and a reflux condenser. React at 75 °C for 6 h. After the reaction is complete, remove part of the solvent by rotary evaporation. Pour the remaining reaction solution into cold deionized water and filter to separate the solid to obtain the reactive flame retardant. The graphene-modified flame-retardant nylon plastic was prepared by melt extrusion of various raw materials in a twin-screw extruder at a temperature of 285℃.

[0024] Comparative Example 1 The difference between this comparative example and Example 3 is that a reactive flame retardant is not prepared, and the commercially available flame retardant DOPO is used to replace the reactive flame retardant in the raw materials.

[0025] A graphene-modified flame-retardant nylon plastic comprises the following raw materials in parts by weight: 100 parts nylon 66 resin, 2.2 parts reduced graphene oxide, 8 parts flame retardant DOPO, 0.3 parts antioxidant 1035, and 0.1 parts antioxidant 168. The graphene-modified flame-retardant nylon plastic was prepared by melt extrusion of various raw materials in a twin-screw extruder at a temperature of 285℃.

[0026] Comparative Example 2 The difference between this comparative example and Example 3 is that the reduced graphene oxide in the raw materials is removed, and an equal amount of reactive flame retardant is used to replace the reduced graphene oxide.

[0027] A graphene-modified flame-retardant nylon plastic comprises the following raw materials in parts by weight: 100 parts nylon 66 resin, 2.2 parts reactive flame retardant, 0.3 parts antioxidant 1035, and 0.1 parts antioxidant 168; The reactive flame retardant is prepared by the following method: S1. 0.1 mol 4-bromobut-2-enoic acid, 0.15 mol diphenyl phosphite, 0.01 mol 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 80 mL tetrahydrofuran were mixed in a three-necked flask equipped with a thermometer and a reflux condenser. The mixture was reacted at 60 °C for 2 h. The reaction solution was then evaporated to dryness, and the remaining solid was eluted by silica gel column chromatography to obtain an intermediate. S2. Mix 0.08 mol of intermediate, 0.12 mol of N,N-diethylethylenediamine, and 80 mL of N,N-dimethylformamide in a three-necked flask equipped with a thermometer and a reflux condenser. React at 75 °C for 6 h. After the reaction is complete, remove part of the solvent by rotary evaporation. Pour the remaining reaction solution into cold deionized water and filter to separate the solid to obtain the reactive flame retardant. The graphene-modified flame-retardant nylon plastic was prepared by melt extrusion of various raw materials in a twin-screw extruder at a temperature of 285℃.

[0028] Experimental Example The composite modified flame-retardant nylon plastics in Examples 1-3 and Comparative Examples 1-2 were subjected to performance tests. The tensile strength of each component of the nylon plastic was tested according to GB / T 1040.2-2006 "Determination of Tensile Properties of Plastics". The volume resistivity of each component was tested according to GB / T 1410-2006 "Test Methods for Volume Resistivity and Surface Resistivity of Solid Insulating Materials". The thermal conductivity of each component was tested according to GB / T 10297-2015 "Determination of Thermal Conductivity of Non-metallic Solid Materials". The limiting oxygen index of each component was tested according to GB / T 2406.1-2008 "Determination of Combustion Behavior of Plastics by Oxygen Index Method". The test results are shown in Table 1.

[0029] As can be seen from Table 1, the nylon plastics in Examples 1 to 3 have higher tensile strength, but the nylon plastic in Comparative Example 1 has poor tensile properties, indicating that the reactive flame retardant of the present invention has less impact on the mechanical properties of nylon plastics. Comparative Example 1 shows that the reactive flame retardant of the present invention can effectively enhance the modification effect of graphene on nylon plastics. Comparative Example 2 shows that graphene can effectively improve the flame retardant effect of nylon plastics.

[0030] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A graphene-modified flame-retardant nylon plastic, characterized in that, It contains the following raw materials: nylon resin, graphene, reactive flame retardant, and antioxidant; The reactive flame retardant structure contains carboxyl and amino groups; Reactive flame retardants are prepared by the following methods: An intermediate is obtained by Michael addition reaction of unsaturated carboxylic acids with organophosphorus compounds, and then the intermediate is reacted with aliphatic amines to produce a reactive flame retardant.

2. The graphene-modified flame-retardant nylon plastic according to claim 1, characterized in that, The nylon resin is at least one of nylon 6 and nylon 66.

3. The graphene-modified flame-retardant nylon plastic according to claim 1, characterized in that, The graphene is reduced graphene oxide.

4. The graphene-modified flame-retardant nylon plastic according to claim 1, characterized in that, The antioxidant is at least one of antioxidant 1010, antioxidant 1035, and antioxidant 168.

5. The graphene-modified flame-retardant nylon plastic according to claim 1, characterized in that, It contains the following raw materials in parts by weight: 100 parts nylon resin, 1.8 to 2.2 parts graphene, 8 to 10 parts reactive flame retardant, and 0.2 to 0.4 parts antioxidant.

6. The graphene-modified flame-retardant nylon plastic according to claim 1, characterized in that, Graphene-modified flame-retardant nylon plastic was prepared by melt extrusion of various raw materials.

7. The graphene-modified flame-retardant nylon plastic according to claim 1, characterized in that, The unsaturated carboxylic acid is at least one of 4-chloro-2-butenoic acid and 4-bromobutenoic acid.

8. The graphene-modified flame-retardant nylon plastic according to claim 1, characterized in that, The organophosphorus compound contains at least one phosphonate group in its structure.

9. The graphene-modified flame-retardant nylon plastic according to claim 1, characterized in that, The fatty amine is at least one of N,N-dimethylethylenediamine and N,N-diethylethylenediamine.

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