CN114874543A - High-strength conductive plastic and preparation method thereof - Google Patents

Abstract

The invention relates to a high-strength conductive plastic and a preparation method thereof, belonging to the technical field of high polymer materials, wherein the plastic comprises the following raw materials in parts by weight: 70-90 parts of homopolymerized polypropylene, 5-8 parts of carbon nano tube, 12-14 parts of modified conductive carbon black, 4-6 parts of anti-aging additive, 5-7 parts of compatible additive and 0.1-0.5 part of polydimethylsiloxane; and obtaining the high-strength conductive plastic through extrusion processing, hot press molding and cooling; aiming at some problems of conductive plastics in the prior art, polyaniline is grafted on the surface of conductive carbon black by modifying the carbon black, has higher conductivity, belongs to a conductive polymer material, and utilizes the conductivity of the polyaniline; after polyaniline is grafted on the surface of the conductive carbon black, the compatibility of the conductive carbon black in the material can be improved. In addition, the invention also improves the performance of heat aging resistance by adding an anti-aging additive.

Description

A kind of high-strength conductive plastic and preparation method thereof

technical field

The invention belongs to the technical field of polymer materials, and in particular relates to a high-strength conductive plastic and a preparation method thereof.

Background technique

Conductive plastic is a functional polymer material that is mixed with resin and conductive material and processed in the same way as plastic. Conductive plastics are mainly used in antistatic additives, computer anti-electromagnetic screens, smart windows, light-emitting diodes, solar cells, mobile phones, micro TV screens and other fields.

Carbon black has a small particle size and a large specific surface area. It is usually added to the substrate to prepare conductive plastics. However, conductive plastics have low volume resistivity and require more conductive channels. Therefore, a large amount of carbon black needs to be added, which will easily lead to carbon black dispersion. Poor compatibility with plastics greatly affects the flexibility, physical and mechanical properties and processability of the material.

SUMMARY OF THE INVENTION

In order to solve the technical problems mentioned in the background art, the present invention provides a high-strength conductive plastic and a preparation method thereof.

The object of the present invention can be realized through the following technical solutions:

A high-strength conductive plastic, comprising the following raw materials in parts by weight: 70-90 parts of homopolypropylene, 5-8 parts of carbon nanotubes, 12-14 parts of modified conductive carbon black, 4-6 parts of anti-aging additives, compatible 5-7 parts of additives, 0.1-0.5 parts of polydimethylsiloxane;

Further, the modified conductive carbon black is prepared by the following steps:

Step S11: Mix the conductive carbon black, the silane coupling agent KH-560 and the aqueous ethanol solution, and stir at a temperature of 80° C. for 60 min. After the stirring, filter and dry the obtained product to obtain a modified coupling agent. carbon black;

Step S12, mix aniline and aqueous hydrochloric acid solution, ultrasonically disperse for 15 minutes, then add ammonium persulfate, stir and react for 6 hours at a temperature of 10 °C, then add coupling agent modified carbon black and additives, keep the temperature unchanged, and continue The reaction was stirred for 4 h to obtain modified conductive carbon black.

Aniline undergoes a polymerization reaction under the action of the initiator ammonium persulfate to form a soluble prepolymer. During the reaction, the carbon black modified by the coupling agent is added to the reaction system, and the epoxy resin on the surface of the carbon black modified by the coupling agent is added. The modified conductive carbon black was prepared by reacting the base with the secondary amine in the prepolymer. Polyaniline is grafted on the surface of conductive carbon black. Polyaniline has high conductivity and belongs to conductive polymer materials. Using the conductivity of polyaniline, at the same time, after grafting polyaniline on the surface of conductive carbon black, it can also improve the Compatibility of conductive carbon blacks in materials.

Further, the auxiliary agent is prepared by the following steps:

Mix n-propyl methacrylate, octafluoropentyl methacrylate and N,N-dimethylformamide, add initiator benzoyl peroxide at 90°C, stir for 60min, and then add methacrylic acid Glycidyl ester, keep the temperature unchanged, continue to stir and react for 3 hours, after the reaction is completed, add it to cool to room temperature, and then dilute with deionized water until the solid content is about 30% to obtain the auxiliary agent. The auxiliary agent belongs to the copolymer, n-propyl methacrylate, octafluoropentyl methacrylate and glycidyl methacrylate are used as reaction monomers, and octafluoropentyl methacrylate is introduced as a hydrophobic monomer. Glycerides link the hydrophobic structure with polyaniline to improve the hydrophobicity of the surface.

Further, the molar ratio of n-propyl methacrylate and octafluoropentyl methacrylate is 1:1, and the amount-to-mass ratio of octafluoropentyl methacrylate and glycidyl methacrylate is 10:0.4; the initiator The molar ratio of the amount to n-propyl methacrylate is 0.05:1.

Further, in step S11, the volume fraction of the ethanol aqueous solution is 90%, and the dosage ratio of the conductive carbon black, the silane coupling agent KH-560 and the ethanol aqueous solution is 100 g: 5 g: 200 mL;

Further, in step S12, the molar ratio of ammonium persulfate and aniline is 1:1; the molar concentration of the hydrochloric acid aqueous solution is 1mol/L, and the consumption-mass ratio of coupling agent modified carbon black, auxiliary agent and aniline is 4:2: 9.

Further, anti-aging additives include lignin and antioxidant components.

Further, the mass ratio of lignin and antioxidant components is 1:10.

Further, the antioxidant component is prepared by the following steps:

Step S21, at 0°C, add octadecylamine and potassium carbonate into N,N-dimethylformamide and mix, and then add β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride After the addition, the reaction was stirred at a temperature of 20 ° C for 15 h. After the reaction was completed, the solvent was removed, extracted with dichloromethane, and then washed with aqueous sodium bicarbonate solution, aqueous hydrochloric acid solution and saturated brine in turn. After washing, rotary evaporation Remove the solvent and dry to obtain the intermediate product a;

Step S22 , mixing the titanate coupling agent and absolute ethanol, then adding chopped carbon fibers, adding intermediate product a while stirring at 65° C., and continuing to stir for 4 hours. Then, the antioxidant component is obtained by standing, filtering and drying.

Further, in step S21, the molar ratio of octadecylamine, potassium carbonate and β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl chloride is 1:1:1;

In step S22, the dosage ratio of titanate coupling agent, absolute ethanol, chopped carbon fiber and intermediate product a is 3 g: 100 mL: 20 g: 3 g.

When using the titanate coupling agent, use acetone to dissolve it before use; the titanate coupling agent chooses NDZ-311, which contains long-chain alkyl groups. The chain and the long-chain molecules in the intermediate product a are intertwined with each other, thereby restricting the movement of the intermediate product a and improving the thermal stability of the intermediate product a.

Further, the compatibilizing additives include EPDM grafted maleic anhydride and lubricating components. The lubricating components include polyethylene glycol and stearic acid; the mass ratio of polyethylene glycol and stearic acid is 10:1; the mass ratio of EPDM rubber grafted maleic anhydride and the lubricating component is 5:1.

A preparation method of high-strength conductive plastic, comprising the following steps:

In parts by weight, the raw materials are mixed to obtain a blend, and then the obtained blend is added to a twin-screw extruder, and the extrusion temperature of the twin-screw extruder is set at 170-190°C, and the extrusion rate is 50- 150r/min for extrusion processing to obtain an extrudate; the extrudate is put into a hot press with a hot pressing temperature of 160-190 ° C for hot pressing, and after hot pressing for 3-10 minutes, it is naturally cooled to obtain a high Strong conductive plastic.

Beneficial effects of the present invention:

In view of some problems existing in the conductive plastics in the prior art, in the present invention, by modifying the carbon black, polyaniline is grafted on the surface of the conductive carbon black. Polyaniline has high electrical conductivity and belongs to the conductive polymer material. The conductivity of polyaniline, and at the same time, after grafting polyaniline on the surface of the conductive carbon black, the compatibility of the conductive carbon black in the material can also be improved.

At the same time, the problem of thermal aging is improved by adding anti-aging additives in the present invention. The anti-aging additives include lignin and antioxidant components; lignin contains a large amount of phenylpropane structural skeleton, which has a certain compatibility with polypropylene, and It contains a large amount of phenolic hydroxyl groups, which can improve the weather resistance of polypropylene materials. The titanate coupling agent in the present invention is NDZ-311, which contains a long-chain alkyl group. On the one hand, it can reduce the polarity of the carbon fiber surface, and use the long chain to interact with the long-chain molecules in the intermediate product a. entanglement, thereby restricting the movement of the intermediate product a, and achieving the effect of improving the thermal stability of the intermediate product a; thereby achieving the purpose of restricting the migration of the antioxidant.

Detailed ways

The technical solutions in the embodiments 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 a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

Preparation of modified conductive carbon black:

Step S11: Mix the conductive carbon black, the silane coupling agent KH-560 and the aqueous ethanol solution, and stir at a temperature of 80° C. for 60 min. After the stirring, filter and dry the obtained product to obtain a modified coupling agent. The volume fraction of ethanol aqueous solution is 90%, and the dosage ratio of conductive carbon black, silane coupling agent KH-560 and ethanol aqueous solution is 100g:5g:200mL;

Mix n-propyl methacrylate, octafluoropentyl methacrylate and N,N-dimethylformamide, add initiator benzoyl peroxide at 90°C, stir for 60min, and then add methacrylic acid Glycidyl ester, keep the temperature unchanged, continue to stir the reaction for 3h, after the reaction is over, add it and cool it to room temperature, then dilute with deionized water until the solid content is about 30%, to obtain the auxiliary agent; n-propyl methacrylate, methyl methacrylate The molar ratio of octafluoropentyl base acrylate is 1:1, the mass ratio of octafluoropentyl methacrylate and glycidyl methacrylate is 10:0.4; the molar ratio of initiator and n-propyl methacrylate is 0.05:1.

Step S12, mix aniline and aqueous hydrochloric acid solution, ultrasonically disperse for 15 minutes, then add ammonium persulfate, stir and react for 6 hours at a temperature of 10 °C, then add coupling agent modified carbon black and additives, keep the temperature unchanged, and continue The reaction was stirred for 4 h to obtain modified conductive carbon black. The molar ratio of ammonium persulfate and aniline is 1:1; the molar concentration of the hydrochloric acid aqueous solution is 1mol/L, and the amount-to-mass ratio of coupling agent modified carbon black, auxiliary agent and aniline is 4:2:9.

Example 2

The anti-aging additive includes lignin and antioxidant components; the mass ratio of lignin and antioxidant components is 1:10. The antioxidant component is prepared by the following steps:

Step S21, at 0°C, add octadecylamine and potassium carbonate into N,N-dimethylformamide and mix, and then add β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride After the addition, the reaction was stirred at a temperature of 20 ° C for 15 h. After the reaction was completed, the solvent was removed, extracted with dichloromethane, and then washed with aqueous sodium bicarbonate solution, aqueous hydrochloric acid solution and saturated brine in turn. After washing, rotary evaporation The solvent is removed and dried to obtain intermediate product a; the molar ratio of octadecylamine, potassium carbonate and β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride is 1:1:1;

Step S22 , mixing the titanate coupling agent and absolute ethanol, then adding chopped carbon fibers, adding intermediate product a while stirring at 65° C., and continuing to stir for 4 hours. Then, the antioxidant component is obtained by standing, filtering and drying. The dosage ratio of titanate coupling agent, absolute ethanol, chopped carbon fiber and intermediate product a is 3g:100mL:20g:3g.

Example 3

A preparation method of high-strength conductive plastic, comprising the following steps:

In parts by weight, 70 parts of homopolypropylene, 5 parts of carbon nanotubes, 12 parts of modified conductive carbon black prepared in Example 1, 4 parts of anti-aging additives in Example 2, 5 parts of compatible additives, 0.1 part of polydimethylsiloxane was mixed to obtain a blend, and then the obtained blend was added to a twin-screw extruder, and the extrusion temperature of the twin-screw extruder was set to 170 ° C and the extrusion rate was 50 r/ The extrudate is extruded for 3 minutes to obtain an extrudate; the extrudate is placed in a hot press with a hot pressing temperature of 190° C. for hot pressing, and after hot pressing for 3 minutes, it is naturally cooled to obtain a high-strength conductive plastic. Among them, the compatibilizing additives include EPDM rubber grafted maleic anhydride and lubricating components. The lubricating components include polyethylene glycol and stearic acid; the mass ratio of polyethylene glycol and stearic acid is 10:1; the mass ratio of EPDM rubber grafted maleic anhydride and the lubricating component is 5:1.

Example 4

A preparation method of high-strength conductive plastic, comprising the following steps:

In parts by weight, 80 parts of homopolypropylene, 7 parts of carbon nanotubes, 13 parts of modified conductive carbon black prepared in Example 1, 5 parts of anti-aging additives in Example 2, 6 parts of compatible additives, 0.3 part of polydimethylsiloxane was mixed to obtain a blend, and then the obtained blend was added to the twin-screw extruder, and the extrusion temperature of the twin-screw extruder was set to 180 ° C and the extrusion rate was 100 r/ The extrudate is extruded for 1 min to obtain an extrudate; the extrudate is placed in a hot press with a hot pressing temperature of 180° C. for hot pressing, and after hot pressing for 6 minutes, it is naturally cooled to obtain a high-strength conductive plastic. Among them, the compatibilizing additives include EPDM rubber grafted maleic anhydride and lubricating components. The lubricating components include polyethylene glycol and stearic acid; the mass ratio of polyethylene glycol and stearic acid is 10:1; the mass ratio of EPDM rubber grafted maleic anhydride and the lubricating component is 5:1.

Example 5

A preparation method of high-strength conductive plastic, comprising the following steps:

By weight, 90 parts of homopolypropylene, 8 parts of carbon nanotubes, 14 parts of modified conductive carbon black prepared in Example 1, 6 parts of anti-aging additives in Example 2, 7 parts of compatible additives, 0.5 part of polydimethylsiloxane was mixed to obtain a blend, and then the obtained blend was added to a twin-screw extruder, and the extrusion temperature of the twin-screw extruder was set to 190 ° C and the extrusion rate was 150 r/ The extrudate is extruded for 10 minutes to obtain an extrudate; the extrudate is placed in a hot press with a hot pressing temperature of 160° C. for hot pressing, and after hot pressing for 10 minutes, it is naturally cooled to obtain a high-strength conductive plastic. Among them, the compatibilizing additives include EPDM rubber grafted maleic anhydride and lubricating components. The lubricating components include polyethylene glycol and stearic acid; the mass ratio of polyethylene glycol and stearic acid is 10:1; the mass ratio of EPDM rubber grafted maleic anhydride and the lubricating component is 5:1.

Comparative Example 1

The modified conductive carbon black in Example 4 was replaced with unmodified conductive carbon black, and the remaining raw materials and preparation process remained unchanged.

Comparative Example 2

The anti-aging additive in Example 4 was replaced with lignin and chopped carbon fiber, and the mass ratio of lignin and chopped carbon fiber was 1:10.

The samples prepared in Examples 3-5 and Comparative Examples 1-2 were tested; volume resistivity JJG-1993 (Ω·cm); tensile strength GB/T1040.3-2006; performance after thermal aging (100°C ×168h); the test results are shown in Table 1 below:

Table 1

It can be seen from the above table 1 that the conductive plastic prepared by the present invention has good aging resistance, good mechanical properties, and small volume resistivity, and has good application prospects.

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

The above contents are only examples and descriptions of the present invention, and those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them in similar ways, as long as they do not deviate from the invention or exceed the present rights The scope defined by the claims shall all belong to the protection scope of the present invention.

Claims (8)

1. a high-strength conductive plastic, is characterized in that, comprises the following raw materials in parts by weight: 70-90 parts of homopolypropylene, 5-8 parts of carbon nanotubes, 12-14 parts of modified conductive carbon black, 4 parts of anti-aging additives -6 parts, 5-7 parts of compatibility additives, 0.1-0.5 parts of polydimethylsiloxane; The modified conductive carbon black is prepared by the following steps: Step S11 , mixing the conductive carbon black, the silane coupling agent and the ethanol aqueous solution, and stirring for 60 minutes at a temperature of 80° C. to obtain the coupling agent-modified carbon black; Step S12, mix aniline and aqueous hydrochloric acid solution, ultrasonically disperse for 15 minutes, then add ammonium persulfate, stir and react for 6 hours at a temperature of 10 °C, then add coupling agent modified carbon black and additives, keep the temperature unchanged, and continue The reaction was stirred for 4 h to obtain modified conductive carbon black. 2. a kind of high-strength conductive plastic according to claim 1, is characterized in that, described auxiliary agent is prepared by following steps: Mix n-propyl methacrylate, octafluoropentyl methacrylate and N,N-dimethylformamide, add initiator at 90°C, stir for 60min, then add glycidyl methacrylate, keep The temperature remained unchanged, and the stirring reaction was continued for 3 h to obtain the auxiliary agent. 3. A kind of high-strength conductive plastic according to claim 2, wherein the molar ratio of n-propyl methacrylate and octafluoropentyl methacrylate is 1:1, and octafluoropentyl methacrylate and The mass ratio of glycidyl methacrylate is 10:0.4; the molar ratio of initiator and n-propyl methacrylate is 0.05:1. 4 . The high-strength conductive plastic according to claim 1 , wherein the anti-aging additive comprises lignin and antioxidant components. 5 . 5 . The high-strength conductive plastic according to claim 4 , wherein the mass ratio of lignin and antioxidant components is 1:10. 6 . 6. A kind of high-strength conductive plastic according to claim 4, is characterized in that, anti-oxidation component is prepared by following steps: Step S21, at 0°C, add octadecylamine and potassium carbonate into N,N-dimethylformamide and mix, and then add β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl chloride , and after the addition, the reaction was stirred for 15 h at a temperature of 20 °C to obtain an intermediate product a; Step S22 , mixing the titanate coupling agent and absolute ethanol, then adding chopped carbon fibers, adding the intermediate product a while stirring at 65° C., and continuing to stir for 4 hours to obtain the antioxidant component. 7. a kind of high-strength conductive plastic according to claim 1, is characterized in that, compatible additive comprises EPDM grafted maleic anhydride and lubricating component; Lubricating component comprises polyethylene glycol, stearin acid; the mass ratio of polyethylene glycol and stearic acid is 10:1; the mass ratio of EPDM rubber grafted maleic anhydride and lubricating component is 5:1. 8. the preparation method of a kind of high-strength conductive plastic according to claim 1, is characterized in that, comprises the steps: In parts by weight, the raw materials are mixed to obtain a blend, and then the obtained blend is added to a twin-screw extruder for extrusion processing to obtain an extrudate; the extrudate is placed in a hot-pressing temperature of 160 Hot pressing is carried out in a hot press at -190°C, and after hot pressing for 3-10 minutes, it is naturally cooled to obtain a high-strength conductive plastic.