Nanometer carbon black synergistically modified by polyaniline and maleic anhydride as well as preparation method and application of nanometer carbon black

Abstract

The invention discloses polyaniline and maleic anhydride synergistically modified nano carbon black as well as a preparation method and application thereof. The preparation method comprises the following steps: blending an aniline monomer, maleic anhydride and nano carbon black in a mass ratio of (0.5-2): (0.1-0.5): 1 in an acidic aqueous solution, adding an oxidizing agent, and reacting at 0-5 DEG C for 8-12 hours to obtain the polyaniline and maleic anhydride synergistically modified nano carbon black. According to the invention, polyaniline and maleic anhydride are adopted to carry out synergistic modification on nano carbon black, a coating layer is formed by in-situ polymerization of polyaniline on the surface of carbon black, meanwhile, a ring-opening product of maleic anhydride and hydroxyl on the surface of carbon black form an ester bond, and the ring-opening product of maleic anhydride and amino on a polyaniline molecular chain form amido bond bridging, so that ternary synergistic covalent modification is realized. The structure effectively improves the dispersion stability of the nano carbon black, so that the nano carbon black is more uniformly dispersed in a polymer matrix, and the interface bonding is tighter.

Description

Technical Field

[0001] This invention relates to nanocomposite materials, specifically to a nanocarbon black synergistically modified with polyaniline and maleic anhydride, its preparation method, and its application in composite cable core wrapping materials. Background Technology

[0002] In the structural design of power and communication cables, the cable core wrapping tape, as a key component protecting the cable core and providing insulation shielding and mechanical buffering functions, plays a crucial role in ensuring the overall structural stability and long-term reliable operation of the cable. Thermoplastic polyurethane (TPU) is widely used as the wrapping tape matrix material due to its excellent elasticity, abrasion resistance, and high mechanical strength; however, it still has significant shortcomings in high-temperature resistance, flame retardancy, and electromagnetic interference resistance. Nano-carbon black, as a commonly used functional filler, can effectively enhance the conductivity, mechanical properties, and thermal stability of polymers; however, due to its extremely high specific surface area and surface energy, nano-carbon black particles are prone to agglomeration, resulting in poor interfacial compatibility with polymer matrices such as TPU. This leads to uneven dispersion within the matrix, easily forming stress defect points, and severely affecting the improvement of the overall performance of the composite material.

[0003] To improve the dispersibility and compatibility of nano-carbon black with the matrix, existing surface modification methods are mostly single chemical treatments, such as oxidation, silanization, or polymer coating. While these methods can improve dispersibility to some extent, the stability of the modified layer is insufficient, making it difficult to maintain long-term compatibility under complex stress or environments. Furthermore, improper matching of carbon black content with processing technology can also lead to large fluctuations in the performance of composite materials, making it difficult to meet the technical requirements of high-end cable wrapping tapes. Summary of the Invention

[0004] To address the problems of easy agglomeration, weak interfacial bonding, and limited functionality of nano-carbon black in TPU matrix composites, this invention provides a method for preparing nano-carbon black synergistically modified with polyaniline and maleic anhydride, and its application in composite cable core wrapping materials. This method significantly improves the dispersibility and interfacial compatibility of nano-carbon black in TPU and other polymer matrices containing polar groups by constructing a ternary synergistic covalent modification structure, while simultaneously endowing the material with excellent electrical conductivity and mechanical properties, making it suitable for the industrial production of high-performance composite cable core wrapping materials.

[0005] To achieve the above objectives, the present invention provides a method for preparing polyaniline and maleic anhydride synergistically modified nano-carbon black, comprising the following steps: mixing aniline monomer, maleic anhydride, and nano-carbon black in an acidic aqueous solution at a mass ratio of (0.5-2):(0.1-0.5):1, adding an oxidant, and then heating in an acidic aqueous solution at 0-5... o The reaction was carried out at C for 8–12 h to obtain nano-carbon black synergistically modified by polyaniline and maleic anhydride.

[0006] The modification mechanism of the above technical solution lies in the following: under the oxidizing action of the oxidant, aniline undergoes oxidative polymerization to form a polyaniline coating layer, while maleic anhydride undergoes ring-opening. After ring-opening, one end of the maleic anhydride forms an ester bond with the hydroxyl groups on the surface of the nano-carbon black through an esterification reaction, and the other end forms an amide bond with the amino groups on the polyaniline molecular chain through an amidation reaction, thereby constructing a stable and synergistic network with "ester bond-amide bond" bridging among the nano-carbon black, polyaniline, and maleic anhydride.

[0007] After this modification, the nano-carbon black is firmly loaded into the polyaniline-maleic anhydride composite system through chemical bonding, and its surface polarity and reactivity are significantly enhanced. The modified nano-carbon black can interact strongly with polar groups (such as amino and ester groups) in polymer matrices such as TPU, which greatly improves its dispersion uniformity and interfacial bonding in the composite cable core wrapping tape, thereby endowing the composite material with excellent comprehensive properties.

[0008] Reaction temperature has a crucial impact on the degree of polymerization of polyaniline and the grafting efficiency of maleic anhydride. Temperatures above 5°C... o C easily leads to excessively rapid polymerization of aniline and uneven product structure; temperatures below 0°C... o C results in a reaction rate that is too slow, reducing grafting efficiency. Preferably, the reaction temperature is 0–2 °C. o C, with a reaction time of 10 h, achieves high grafting efficiency while ensuring reaction uniformity.

[0009] Preferably, the mass ratio of the aniline monomer, maleic anhydride and nano carbon black is (0.8-1.2):(0.2-0.4):1, and more preferably 1:0.3:1.

[0010] Preferably, the acidic aqueous solution is a hydrochloric acid solution with a pH value of 1 to 3.

[0011] Specifically, the oxidant includes, but is not limited to, one of ammonium persulfate, potassium persulfate, sodium persulfate, ferric chloride, or ferric sulfate. Ammonium persulfate is preferred, and the amount of oxidant can be adjusted adaptively according to its oxidative equivalent, with a molar ratio of (0.5–1.5):1 to the aniline monomer.

[0012] Preferably, the molar ratio of ammonium persulfate to aniline monomer is 1:1.

[0013] Furthermore, after the reaction is complete, the reaction product is filtered, washed, and dried to obtain nano-carbon black synergistically modified by polyaniline and maleic anhydride.

[0014] The second aspect of the present invention provides nano-carbon black synergistically modified with polyaniline and maleic anhydride obtained by the above preparation method.

[0015] The third aspect of this invention provides the application of the above-mentioned polyaniline and maleic anhydride synergistically modified nano-carbon black in the preparation of composite cable core wrapping materials.

[0016] Through the above technical solution, the present invention achieves the following beneficial effects: 1. This invention employs polyaniline and maleic anhydride to synergistically modify nano-carbon black. The in-situ polymerization of polyaniline on the carbon black surface forms a coating layer, while the ring-opening product of maleic anhydride forms ester bonds with the hydroxyl groups on the carbon black surface and amide bonds with the amino groups on the polyaniline molecular chain, achieving ternary synergistic covalent modification. This structure effectively improves the dispersion stability of nano-carbon black, resulting in more uniform dispersion and tighter interfacial bonding within the polymer matrix.

[0017] 2. Through the aforementioned diversified chemical bonding, the modified nano-carbon black can be firmly embedded in the polymer matrix, making it less prone to agglomeration and detachment, thus significantly improving its dispersibility and interfacial compatibility in the composite material. This modification strategy effectively enhances the continuity of the conductive network while improving the mechanical properties and durability of the composite system.

[0018] 3. The introduction of polyaniline and maleic anhydride not only enhances the chemical compatibility between nano-carbon black and the matrix material, but also significantly improves interfacial adhesion through the formation of strong bonds such as amide bonds and ester bonds. Experiments show that the prepared nano-carbon black / TPU composite tape material possesses the following comprehensive properties: oxygen index ≥30%, thermal shrinkage ≤5%, smoke density ≤200, and power frequency dielectric strength (20...). o C) ≥15 kV / mm, tensile strength ≥25 MPa, fully meeting the technical requirements of high-performance cable core wrapping.

[0019] 4. The modification process used in this invention is mild, the reaction is carried out in the aqueous phase, no toxic byproducts are generated during the process, the process parameters are easy to control, and it has good potential for industrial production.

[0020] 5. This method effectively solves the problems of poor dispersion, weak interface, and easy migration of nano-carbon black in polymer matrices containing polar groups such as TPU. The optimized composite material exhibits excellent performance in terms of anti-interference, weather resistance, and anti-aging, and is suitable for the production of high-reliability cable core wrapping tape, with significant engineering application value and market prospects. Attached Figure Description

[0021] Figure 1 The image shows the distribution of polyaniline and maleic anhydride synergistically modified nano-carbon black in a TPU matrix, prepared by the methods of Example 1 and Comparative Example 1 of this invention. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in detail below with reference to examples. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0023] Example 1 Aniline monomer, maleic anhydride, and nano-carbon black were mixed in a hydrochloric acid aqueous solution at pH 2 at a mass ratio of 1:0.3:1. Ammonium persulfate was then added in a molar ratio of 1:1 to the aniline monomer. o The reaction was carried out at C for 10 h. After the reaction was completed, the mixture was filtered, washed, and dried to constant weight to obtain nano-carbon black synergistically modified with polyaniline and maleic anhydride. The modified nano-carbon black was melt-blended with TPU particles at a mass ratio of 1:19 in a twin-screw extruder, granulated, and then calendered to obtain a composite cable core wrapping material.

[0024] Examples 2 to 7: The same steps as in Example 1 were used, except that the mass ratio of aniline monomer, maleic anhydride and nano carbon black was changed (see table below).

[0025]

[0026] Examples 8 to 9: The same steps as in Example 1 were used, except that the type of acidic solution was changed (see table below).

[0027]

[0028] Examples 10 to 11: The same steps as in Example 1 were used, except that the pH of the acidic solution was changed (see table below).

[0029]

[0030] Examples 12 to 14: The same steps as in Example 1 were used, except that the type of oxidant was changed (see table below).

[0031]

[0032] Examples 15 to 16: The same steps as in Example 1 were used, except that the molar ratio of aniline monomer and ammonium persulfate was changed (see table below).

[0033]

[0034] Examples 17 to 19: The same steps as in Example 1 were used, except that the reaction temperature was changed (see table below).

[0035]

[0036] Examples 20 to 22: The same steps as in Example 1 were used, except that the reaction time was changed (see table below).

[0037]

[0038] Comparative Example 1 Other conditions were the same as in Example 1, but the nano-carbon black was not subjected to any surface modification treatment and was directly added to TPU at a mass fraction of 5% to prepare the composite material.

[0039] Comparative Example 2 Other conditions are the same as in Example 1, except that the reaction temperature is adjusted to 10 °C. o C.

[0040] Comparative Example 3 Other conditions are the same as in Example 1, except that the reaction time is adjusted to 6 h.

[0041] Comparative Example 4 Other conditions are the same as in Example 1, except that the amount of ammonium persulfate is adjusted to 0.3:1 (relative to the molar amount of aniline monomer).

[0042] Comparative Example 5 Other conditions are the same as in Example 1, except that the pH of the reaction system is adjusted to 5.

[0043] Comparative Example 6 Other conditions are the same as in Example 1, except that the aniline monomer is added first and then the maleic anhydride is added sequentially, instead of the simultaneous mixing and feeding method of the present invention.

[0044] Performance testing like Figure 1 As shown, the polyaniline and maleic anhydride synergistic modification obtained in Example 1 is uniformly dispersed in the TPU matrix without agglomeration; while the unmodified nano carbon black in Comparative Example 1 exhibits obvious agglomerated structure in TPU.

[0045] In addition, the comprehensive performance of the composite cable core wrapping materials obtained in the above embodiments and comparative examples was tested with reference to relevant national standards: Oxygen index: GB / T 2406.2 Heat shrinkage rate: GB / T 18380.3-2001 Smoke density: GB / T 8323.2 Power frequency dielectric strength: GB / T 5019.2 Tensile strength: JB / T 10259 The table below compares the performance of the samples prepared in the above embodiments and comparative examples.

[0046]

[0047] As can be seen from the table above: 1) The modified nano-carbon black prepared by the method of the present invention can significantly improve the comprehensive performance of the composite material, and all indicators meet or exceed the technical requirements.

[0048] 2) By comparing examples with different mass ratios, it can be found that under specific process conditions, when the mass ratio of aniline monomer: maleic anhydride: nano carbon black is 1:0.3:1 (Example 1), the resulting composite material has the best comprehensive performance, with an oxygen index of 32%, a thermal shrinkage rate of only 3.2%, a smoke density of 165, a dielectric strength of 16.8 kV / mm, and a tensile strength of 28.5 MPa.

[0049] 3) The results of each embodiment further verified the influence of mass ratio on product performance. When the proportion of aniline monomer is in the range of 0.8-1.2 and the proportion of maleic anhydride is in the range of 0.2-0.4, the product performance is relatively ideal, with 1:0.3:1 being the optimal ratio.

[0050] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0051] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0052] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing nano-carbon black synergistically modified with polyaniline and maleic anhydride, characterized in that, The process includes the following steps: Aniline monomer, maleic anhydride, and nano-carbon black are mixed in an acidic aqueous solution at a mass ratio of (0.5–2):(0.1–0.5):1; an oxidizing agent is added, and the mixture is then subjected to a solution of 0–5... o The reaction was carried out at C for 8–12 h to obtain nano-carbon black synergistically modified by polyaniline and maleic anhydride.

2. The preparation method according to claim 1, characterized in that, The mass ratio of the aniline monomer, maleic anhydride and nano carbon black is (0.8-1.2):(0.2-0.4):

1.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the aniline monomer, maleic anhydride, and nano carbon black is 1:0.3:

1.

4. The preparation method according to claim 1, characterized in that, The pH value of the acidic aqueous solution is 1 to 3.

5. The preparation method according to claim 1, characterized in that, The oxidant is ammonium persulfate, potassium persulfate, sodium persulfate, ferric chloride, or ferric sulfate, and its molar ratio with aniline monomer is (0.5-1.5):

1.

6. The preparation method according to claim 5, characterized in that, The molar ratio of ammonium persulfate to aniline monomer is 1:

1.

7. The preparation method according to claim 1, characterized in that, After the reaction was completed, the reaction product was filtered, washed and dried to obtain nano-carbon black synergistically modified by polyaniline and maleic anhydride.

8. The nano-carbon black synergistically modified with polyaniline and maleic anhydride prepared by the method of any one of claims 1 to 7.

9. The application of the polyaniline and maleic anhydride synergistically modified nano-carbon black according to claim 8 in the preparation of composite cable core wrapping materials.

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