Chitosan-black talc composite for mildew and antibacterial properties of rubber cables and its preparation and application

Abstract

The present invention discloses a chitosan-black talc composite for rubber cable mildew and antibacterial properties, and its preparation and application. The chitosan-black talc composite is obtained by a graft copolymerization method. As a natural mildew and antibacterial agent, the composite can be directly added to the preparation of rubber cables without much effect on the mechanical properties of the rubber itself. The mildew and antibacterial agent can inhibit the growth of 1 to 5 × 10 6 The compound inhibits mold growth, particularly Aspergillus niger and Penicillium funiculosum. Compared to the single-use mildew inhibitors of organic mildew inhibitors, the compound achieves maximum inhibition rates of 97% against Staphylococcus aureus and 99% against Escherichia coli, achieving a synergistic mildew and antibacterial effect on rubber cables. Compared to the oxidation issue associated with the direct addition of methyl sorbate as a mildew inhibitor, the compound grafted with chitosan and combined with black talc to form a polymer stabilizes its structure, extending its mildew-proof life by 2-3 times.

Description

(1) Technical field

[0001] The invention belongs to the field of mildew and antibacterial agents, and relates to a chitosan and black talc composite for mildew and antibacterial properties of rubber cables, and the preparation and application thereof. (2) Background technology

[0002] When rubber cables are exposed to damp, dark environments for extended periods, the proteins and cellulose in natural rubber, as well as additives like plasticizers and stabilizers in synthetic rubber, become nutrients for microorganisms. This can lead to mold growth, degrading the cable's mechanical properties and accelerating its aging process. Failure to replace these cables promptly can lead to a range of safety issues. Therefore, a simple, effective, and environmentally friendly method is needed to prevent mold and aging in rubber cables and extend their service life.

[0003] Common treatment methods for mildew and antibacterial properties include coating and pre-addition of mildew inhibitors. Applying a mildew-resistant coating to the surface of rubber cables offers strong mildew resistance in the initial stage of use, but over time, problems such as coating shedding and decreased mildew resistance often occur. Furthermore, the post-treatment coating process is complex, and the larger the cable surface area, the higher the relative cost. Therefore, mildew and antibacterial agents are often added as additives during the rubber cable manufacturing process. These agents are categorized as inorganic, organic, and natural. While inorganic mildew inhibitors, such as silver-based and non-silver-based (zinc oxide / copper) agents, offer long-lasting mildew resistance, they often suffer from material incompatibility, yellowing and discoloration due to reactions with additives, and are generally expensive. Organic mildew inhibitors, such as isothiazolinone and polyhexamethylbiguanide, offer immediate and effective mildew resistance, but liquid mildew inhibitors often lack long-lasting properties, leak, and are highly toxic, causing significant environmental pollution. Natural mildew inhibitors are low-cost, readily available, and non-toxic. However, single natural materials offer limited effectiveness and are prone to decomposition.

[0004] In summary, it is necessary to find a green, efficient, and low-cost natural mildew and antibacterial agent to improve the problem of mildew and aging of rubber cables in dark and humid environments. (3) Summary of the invention

[0005] The present invention provides a chitosan-black talc composite for the mildew and antibacterial properties of rubber cables, and its preparation and application. The composite comprises a chitosan-black talc composite structure comprising a sorbic acid organic derivative chitosan grafted copolymer and a black talc composite structure, prepared by grafting and polymerizing the carbon-carbon unsaturated bonds of an organic sorbic acid derivative with the amino groups of chitosan and then compounding with the amino groups of silane-modified black talc. The polymer formed by copolymerization of the organic sorbic acid derivative with chitosan is stable and resistant to decomposition. The grafting of chitosan and the composite of black talc enhance its antibacterial properties, while also providing protection against anaerobic bacteria. The resulting composite and rubber, both natural polymers, exhibit good compatibility, thus resolving the problem of poor compatibility between inorganic and organic mildew inhibitors and rubber. As a natural mildew and antibacterial agent, the composite offers advantages such as environmental friendliness, good compatibility, and long-term stability, making it particularly suitable as an additive to alleviate mildew and aging issues in rubber cables.

[0006] The technical solution adopted in the present invention is:

[0007] The present invention provides a chitosan-black talc composite for preventing mildew and resisting bacteria in rubber cables. The composite is prepared according to the following method:

[0008] S1: Preparation of activated chitosan solution: Dissolve chitosan (CHI) in an organic acid aqueous solution, stir until the CHI is completely dissolved, heat to 40-60°C, slowly add an aqueous solution of an initiator dropwise, and keep the temperature to react for 3-4 hours after the addition is complete to obtain an activated chitosan solution; the initiator is one of benzoyl peroxide, tert-butyl benzoyl peroxide, and ammonium persulfate, preferably ammonium persulfate;

[0009] S2: Preparation of modified black talc powder: black talc (BT) was dispersed in water, heated to 60-80°C, sodium hydroxide was added, and the mixture was stirred and reacted for 4-6 hours. The mixture was allowed to stand and cool to room temperature. The mixture was filtered with suction, and the filter cake was washed with water and ethanol, respectively, and dried to obtain a gray powder, which is the alkalized black talc. The alkalized black talc was then dissolved in toluene, heated to 60-80°C, γ-aminoethylaminopropyltrimethoxysilane (A-1120) was added, and the mixture was stirred and reacted for 6-10 hours. After the reaction was completed, the mixture was cooled to room temperature. The mixture was filtered with suction, and the filter cake was washed with water and ethanol, respectively, and dried to obtain the modified black talc powder.

[0010] S3: Preparation of chitosan-black talc composite: dissolve sorbic acid organic derivative in deionized water and stir until completely dissolved to obtain sorbic acid organic derivative solution; add sorbic acid organic derivative solution and modified black talc powder prepared in step S2 to the entire activated chitosan solution prepared in step S1, introduce N2, stir and polymerize at 40-60°C for 4-8 hours. When the solution gradually changes from transparent to a light yellow suspension, introduce air to stop the reaction, let it stand and cool to room temperature, filter, wash with water, acetone and ethanol in sequence, and dry to obtain a light yellow powdery chitosan-black talc composite.

[0011] Furthermore, in step S1, the organic acid in the organic acid aqueous solution includes acetic acid, acetic acid, and citric acid; the concentration of the organic acid aqueous solution is 2-10 g / L (preferably 10 g / L), and preferably the organic acid aqueous solution is a 10 g / L acetic acid aqueous solution.

[0012] Furthermore, in step S1, the mass ratio of CHI to initiator is 1:0.005-0.02 (preferably 1:0.01-0.02, particularly preferably 1:0.015); the volume of the organic acid aqueous solution is 40-120 mL / g (preferably 80 mL / g) based on the mass of chitosan; and the concentration of the initiator aqueous solution is 1-5 g / L (preferably 1.5 g / L).

[0013] Furthermore, in step S2, the mass ratio of the black talc to sodium hydroxide is 1:0.5-2 (preferably 1:1); the volume of water used to disperse the black talc is 10-15 mL / g (preferably 12.5 mL / g) based on the mass of the black talc; the volume of toluene is 10-30 mL / g (preferably 20 mL / g) based on the mass of the alkalized black talc; the mass ratio of the alkalized black talc to A-1120 is 1:0.5-2 (preferably 1:1).

[0014] Furthermore, in step S3, the polymerization reaction is stirred at 50° C. for 6 hours.

[0015] Furthermore, in step S3, the sorbic acid organic derivative is one of sorbic acid, methyl sorbate (HA), and isopropyl sorbate, preferably methyl sorbate; the volume of deionized water is 5 to 40 mL / g (preferably 20 mL / g) based on the mass of the sorbic acid organic derivative; the mass ratio of the sorbic acid organic derivative to the modified black talc powder is 1:0.01-0.1 (preferably 1:0.05); the amount of the activated chitosan solution is based on the mass of the chitosan in step S1, and the mass ratio of the sorbic acid organic derivative to the chitosan is 1:0.2-3 (preferably 1:3).

[0016] Furthermore, the drying in steps S2 and S3 is performed at 60-100° C. for 10-24 hours, preferably at 80° C. for 12 hours.

[0017] The present invention also provides an application of the chitosan-black talc composite in preparing a rubber cable mildew and antibacterial agent.

[0018] Furthermore, the mold inhibited by the mildew and antibacterial agent is one or a mixture of two or more of Aspergillus niger, Aspergillus versicolor, Fusarium spp. or Penicillium funiculosum, preferably Aspergillus niger, Penicillium funiculosum or a mixture of the two; the inhibited bacteria include Staphylococcus aureus or Escherichia coli.

[0019] Furthermore, the application is to add the chitosan black talc compound to a rubber cable raw material to prepare a mildew-proof and antibacterial rubber cable, and the amount of the chitosan black talc compound added is 0.5-2% of the mass of the rubber cable raw material.

[0020] The sorbic acid organic derivative used to prepare the chitosan-black talc composite of the present invention acts as a natural mildew inhibitor. It binds to sulfhydryl groups in the microbial mildew system, disrupting the enzyme activity within it. It also interacts with lipids in the microbial cell membrane, disrupting the cell structure and hindering its reproduction and survival, leading to the death of the microorganisms, resulting in a strong mildew-proofing effect. Chitosan, also a commonly used natural antimicrobial agent, interacts with negatively charged groups on the bacterial cell surface through its polycationic properties, destroying the bacterial cell wall, thereby achieving antibacterial activity. It can form a synergistic antimicrobial effect with sorbic acid and its organic derivatives. Furthermore, as a natural polysaccharide biomass, chitosan exhibits film-forming and biocompatibility properties, which can improve the compatibility of antimicrobial materials with rubber. Black talc, a natural magnesium-rich silicate mineral, produces ROS outside the cells in humid environments. This magnesium oxide attacks the cell membrane, causing it to rupture and leak proteins from the microbial cells, killing bacteria. This improves the insufficient antimicrobial properties of chitosan alone, enhances the chemical stability of natural mildew inhibitors, and, due to its hydrophobicity, enhances compatibility with rubber cables.

[0021] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in:

[0022] The chitosan-black talc composite is obtained by a graft copolymerization method. As a natural mildew and antibacterial agent, it can be used in the preparation of rubber cables by direct addition, and has little effect on the mechanical properties of the rubber itself. The mildew and antibacterial agent can inhibit 1 to 5×10 6 The compound can inhibit the growth of molds, particularly Aspergillus niger and Penicillium funiculosum. Compared to the single-use mildew inhibitory effect of organic mildew inhibitors, the compound achieves maximum inhibition rates of 97% against Staphylococcus aureus and 99% against Escherichia coli, achieving a synergistic mildew and antibacterial effect on rubber cables. Compared to the susceptibility to oxidation associated with the direct addition of methyl sorbate as a mildew inhibitor, the compound grafted with chitosan and combined with black talc to form a polymer stabilizes its structure, extending its mildew-proof life by 2-3 times. (IV) Description of the accompanying drawings

[0023] Figure 1 is the reaction formula of CHI-g-HA / BT in Example 1.

[0024] Figure 2 This is the FT-IR spectrum of CHI-g-HA / BT prepared in Example 1.

[0025] Figure 3This is the anti-mildew performance diagram of CHI-g-HA / BT.

[0026] Figure 4 This is the antibacterial performance diagram of CHI-g-HA / BT.

[0027] Figure 5 This is a test diagram of the mechanical properties of anti-mildew rubber. (V) Specific implementation methods

[0028] The present invention is further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto:

[0029] Example 1: CHI-g-HA / BT (CHI / HA mass ratio 1:3)

[0030] (1) Preparation of activated chitosan solution: Weigh 1 g (6.2 mmol) of chitosan and dissolve it in 80 mL of acetic acid aqueous solution (0.8 g of acetic acid), heat to 50°C, stir until the chitosan is completely dissolved, and slowly add 10 mL of ammonium persulfate aqueous solution (0.015 g of ammonium persulfate dissolved in 10 mL of water). After the addition is complete, react at 50°C for 4 h to obtain the activated chitosan solution.

[0031] (2) Preparation of modified black talc powder: 8 g of black talc was weighed and dispersed in 100 mL of water, heated to 60°C, 8 g of sodium hydroxide was added, and the mixture was stirred and reacted at 60°C for 6 h. After the reaction was completed, the mixture was filtered and the filter cake was washed with water and ethanol respectively, and dried at 80°C for 12 h to obtain 7.8 g of alkaline black talc; 7 g of alkaline black talc was dissolved in 140 mL of toluene, heated to 60°C, 7 g of A-1120 was added, and the mixture was stirred and reacted at 60°C for 8 h. The mixture was allowed to stand and cool to room temperature, filtered, washed three times with water and ethanol respectively, and dried at 80°C for 12 h to obtain 11.3 g of modified black talc powder.

[0032] (3) Chitosan-black talc composite: 3 g (23.8 mmol) of methyl sorbate was weighed and dissolved in 60 mL of deionized water, and stirred until the methyl sorbate was completely dissolved. The methyl sorbate aqueous solution was slowly added to the entire activated chitosan solution of step (1), and then 0.05 g of the modified black talc powder prepared in step (2) was added. N2 was introduced and the polymerization reaction was carried out at 50°C under stirring for 6 h. When the solution gradually changed from transparent to a light yellow suspension, air was introduced to stop the reaction (air was introduced to react with excess free radicals), and the mixture was allowed to stand and cool to room temperature. 100 mL of ethanol was added to precipitate the product, and the filter cake was washed with water and ethanol three times respectively, and dried at 80°C for 12 h to obtain 3.2 g of light yellow powder, which was the chitosan-black talc composite, recorded as CHI-g-HA / BT.

[0033] The infrared spectrometer (Nicolet iS50, Thermo Fisher Scientific) was used for scanning observation at 10 kV. Figure 2 As shown, 1045cm -1 and 797cm -1 The peaks at 993 cm are the Si-O-Si stretching vibration peak and the symmetrical stretching peak, respectively, which prove the composite structure of talc. -1 is the NC amide vibration peak, 1570 cm -1 The stretching vibration of C=C double bond proved the successful grafting of chitosan, thus, the successful grafting copolymerization of methyl sorbate and chitosan was achieved.

[0034] Example 2: Antifungal and antibacterial performance test of CHI-g-HA / BT

[0035] (1) Spore suspension

[0036] Nutrient medium: Dissolve 0.7g potassium dihydrogen phosphate, 0.7g magnesium sulfate heptahydrate, 1g ammonium nitrate, 0.005g sodium chloride, 0.002g ferrous sulfate heptahydrate, 0.002g zinc sulfate heptahydrate, 0.001g manganese sulfate monohydrate, 0.7g potassium dihydrogen phosphate, and 15g agar by heating. Adjust the pH to 6 with 0.001mol / L NaOH solution. Aliquot and autoclave at 121°C for 20 min. The nutrient medium is prepared by removing the agar.

[0037] Preparation of potato-glucose culture medium: Peel 200g of potatoes and extract the juice, add 20g of glucose, 20g of agar and 1L of water, heat to melt, divide into test tubes, sterilize under high pressure at 121℃ for 20min, take out and place at an angle.

[0038] Aspergillus niger spore suspension: Aspergillus niger China Industrial Microbiological Culture Collection Administration Center) was inoculated on potato-glucose medium and cultured at 28°C and 90% humidity until the slant was covered with spores (10 days), and then stored at 5°C. 10 mL of physiological saline was added dropwise, and the physiological saline containing a large number of spores was poured into a conical flask, glass beads were added, the bottle mouth was plugged, and the flask was shaken in a constant temperature oscillator for 2 hours (28°C) to obtain a fully dispersed spore suspension. The filter cake was washed with 50 mL of sterile water and centrifuged (4000 r / min) for 3 times. The number of spores was determined by hemocytometer counting and diluted to 3×10 6 / mL to obtain Aspergillus niger spore suspension.

[0039] Penicillium funiculosum spore suspension: Replace Aspergillus niger with Penicillium funiculosum China Industrial Microorganism Culture Collection Center), other operations were the same as those for Aspergillus niger spore suspension, and 3×10 6 / mL of Penicillium funiculosum spore suspension.

[0040] Mixed mold spore suspension: Mix equal volumes of Aspergillus niger spore suspension and Penicillium funiculosum spore suspension to obtain 3×10 6 / mL of mixed spore suspension.

[0041] (2) Antifungal and antibacterial liquid: CHI-g-HA / BT prepared by the method of Example 1 was dissolved in propylene glycol and stirred until uniformly dispersed to obtain 2 g / L antifungal and antibacterial liquid.

[0042] (3) Anti-mildew performance

[0043] The anti-mildew performance test is carried out according to the requirements of HG / T 4301-2012 "Rubber Anti-mildew Test Standard".

[0044] Take 20 μL of the antifungal and antibacterial solution from step (2) and drip it onto a 6 mm circular filter paper to prepare a sample, which is then air-dried under aseptic conditions. Pour 20 mL of nutrient solution culture medium into a 9 cm diameter culture dish. After solidification, place three parallel samples in the center of the culture medium. Spray 0.5 mL of Aspergillus niger spore suspension, Penicillium funiculosum spore suspension, and mixed mold spore suspension on the surface of each three samples and the surface of the culture medium to keep them moist. Place the sample in a constant temperature and humidity incubator at 28°C and 90% humidity for 7 days. After the incubation period, measure the diameter of the inhibition zone with a vernier caliper and take a photo. The control group is a blank sample.

[0045] The results are as follows Figure 3 As shown in the 1:3 group, the diameters of the inhibition zones of CHI-g-HA / BT against Aspergillus niger, Aspergillus funiculosus and mixed molds were 18 mm, 15 mm and 13 mm, respectively.

[0046] (4) Antibacterial properties

[0047] The antibacterial rate of the antifungal and antibacterial liquid against Staphylococcus aureus and Escherichia coli was tested according to the method of WST650-2019 "Evaluation Method for Antibacterial and Antimicrobial Effects". The results are shown in the table below. Figure 4 In the 1:3 group, the rates were 90% and 93% respectively.

[0048] The calculation formula for the inhibition rate is:

[0049] X=(A0-A1) / A0×100%

[0050] Where:

[0051] X——inhibition rate, %;

[0052] A0——the amount of bacteria recovered in the positive control group, in CFU / ml;

[0053] A1——The amount of bacteria recovered from the test group, in CFU / ml.

[0054] Example 3: CHI-g-HA / BT (CHI / HA mass ratio 3:1, 1:1)

[0055] The amounts of chitosan and methyl sorbate in Example 1 were changed to 3 g (18.6 mmol) and 1 g (7.9 mmol), respectively. Other operations were the same. The mildew and antibacterial tests were carried out using the method of Example 2. The results are shown in FIG. Figure 3 、 4 The diameters of the inhibition zones against Aspergillus niger, Aspergillus funiculosus and mixed molds were 10 mm, 11 mm and 8 mm respectively, and the inhibition rates against Staphylococcus aureus and Escherichia coli were 97% and 99% respectively.

[0056] The dosage of chitosan and methyl sorbate in Example 1 was changed to 2g and 2g respectively, and other operations were the same. The method of Example 2 was used to carry out mildew and antibacterial tests. The results are shown in FIG. Figure 3 、 Figure 4 The diameters of the inhibition zones against Aspergillus niger, Aspergillus funiculosus and mixed molds were 14mm, 13mm and 11mm respectively, and the inhibition rates against Staphylococcus aureus and Escherichia coli were 95% and 93% respectively.

[0057] As the proportion of chitosan increases, the bacterial inhibition effect shows an upward trend, but the mold inhibition effect shows a downward trend. The optimal methyl sorbate doping ratio, that is, the dosage ratio of chitosan to methyl sorbate is 1g (6.2mmol):3g (23.8mmol).

[0058] Example 4: Mechanical properties test of CHI-g-HA / BT

[0059] The quality formula of rubber composite material is: 100 parts of natural rubber, 30 parts of carbon black-N330, 5 parts of zinc oxide, 2 parts of stearic acid, 1.5 parts of accelerator M (2-mercaptobenzothiazole), 2 parts of sulfur and 0.5 parts of antioxidant 4010 (molecular formula C18H 22 N2).

[0060] First, the masterbatch prepared from the rubber composite material according to the formula was placed in an internal mixer and kneaded at 100°C and 40 r / min for 5 minutes. Then, 0 parts, 0.5 parts (0.25 g), and 2 parts (1 g) of CHI-g-HA / BT prepared in Example 1 were added to the masterbatch, and kneaded for 15 minutes to obtain a mildew-proof rubber. The mechanical properties of the obtained mildew-proof rubber were tested in accordance with GB / T 528-2009 "Vulcanized rubber or thermoplastic rubber - Determination of tensile stress and strain". Figure 5As shown in the figure, the tensile strengths were 17.76MPa, 17.53MPa, and 16.87MPa, and the elongations at break were 427%, 418%, and 404%, respectively. The results showed that with the increase in the amount of CHI-g-HA / BT antifungal and antimicrobial agent added, although the tensile strength and elongation at break decreased, the mechanical properties were not significantly affected.

[0061] Comparative Example 1: Antifungal and antibacterial properties of methyl sorbate

[0062] The antifungal and antibacterial liquid in Example 2 was replaced with a 2 g / L methyl sorbate (HA) solution in propylene glycol. Other operations were the same. The results showed that the diameters of the inhibition zones against Aspergillus niger, Aspergillus funiculosus and mixed molds were 16 mm, 12 mm and 9 mm, respectively; the inhibition rates against Staphylococcus aureus and Escherichia coli were 83% and 85%, respectively.

[0063] Comparative Example 2:

[0064] The modified black talc powder in step (3) of Example 1 was removed, and the other operations were the same to obtain CHI-g-HA. The CHI-g-HA / BT in the mildew and antibacterial liquid of Example 2 was replaced with CHI-g-HA, and the other operations were the same. The results were the same as in Example 2. The results showed that the diameters of the inhibition zones against Aspergillus niger, Aspergillus funiculosus, and mixed mildew were 17 mm, 15 mm, and 13 mm, respectively; the inhibition rates against Staphylococcus aureus and Escherichia coli were 87% and 91%, respectively.

[0065] Comparative Example 3:

[0066] The antifungal and antibacterial liquid in Example 2 was replaced with a 2 g / L iodopropynyl butylcarbamate (IPBC) propylene glycol solution. Other operations were the same. The results showed that the diameters of the inhibition zones for Aspergillus niger, Aspergillus funiculosus and mixed molds were 21 mm, 17 mm and 16 mm, respectively; the inhibition rates for Staphylococcus aureus and Escherichia coli were 83% and 87%, respectively.

[0067] Example 5:

[0068] The amount of modified black talc powder in step (3) of Example 1 was changed to 0.1 g, and the obtained chitosan black talc composite was tested according to the method of Example 2. The results showed that the diameters of the inhibition zones for Aspergillus niger, Aspergillus funiculosus and mixed mold were 17 mm, 15 mm and 12 mm, respectively; the inhibition rates for Staphylococcus aureus and Escherichia coli were 92% and 94%, respectively.

Claims

1. A chitosan-black talc composite for mildew and antibacterial properties of rubber cables, characterized in that: The complex was prepared as follows: S1: Preparation of activated chitosan solution: dissolving chitosan in an organic acid aqueous solution, stirring until the chitosan is completely dissolved, heating to 40-60°C, slowly adding an aqueous solution of an initiator dropwise, and keeping the temperature to react for 3-4 hours after the addition is complete to obtain an activated chitosan solution; the initiator is one of benzoyl peroxide, tert-butyl benzoyl peroxide, and ammonium persulfate; the organic acid in the organic acid aqueous solution includes acetic acid, acetic acid, and citric acid; the concentration of the organic acid aqueous solution is 2-10 g / L; S2: Preparation of modified black talc powder: disperse black talc in water, heat to 60-80°C, add sodium hydroxide, keep warm and stir to react for 4-6 hours, let stand and cool to room temperature, filter with suction, wash the filter cake with water and ethanol, respectively, and dry to obtain a gray powder, which is the alkalized black talc; then dissolve the alkalized black talc in toluene, heat to 60-80°C, add γ-aminoethylaminopropyltrimethoxysilane, keep warm and stir to react for 6-10 hours, cool to room temperature after the reaction, filter with suction, wash the filter cake with water and ethanol, respectively, and dry to obtain the modified black talc powder; S3: Preparation of chitosan black talc composite: dissolve sorbic acid organic derivative in deionized water and stir until completely dissolved to obtain sorbic acid organic derivative solution; add sorbic acid organic derivative solution and modified black talc powder prepared in step S2 to all activated chitosan solution prepared in step S1, introduce N2, stir and polymerize at 40-60 ℃ for 4-8h, when the solution gradually changes from transparent to light yellow suspension, introduce air to stop the reaction, let stand and cool to room temperature, filter, and wash with water, acetone and ethanol in turn, and dry to obtain light yellow powdery chitosan black talc composite; the sorbic acid organic derivative is one of sorbic acid, methyl sorbate and isopropyl sorbate; the volume of deionized water is 5-40% based on the mass of the sorbic acid organic derivative. mL / g; the mass ratio of the organic sorbic acid derivative to the modified black talc powder is 1:0.01-0.1; the amount of the activated chitosan solution is based on the mass of the chitosan in step S1, and the mass ratio of the organic sorbic acid derivative to the chitosan is 1:0.2-3.

2. The chitosan-black talc composite according to claim 1, wherein In step S1, the mass ratio of chitosan to initiator is 1:0.005-0.02; the volume of the organic acid aqueous solution is 40-120 mL / g based on the mass of chitosan; and the concentration of the initiator aqueous solution is 1-5 g / L.

3. The chitosan-black talc composite according to claim 1, wherein In step S2, the mass ratio of the black talc to sodium hydroxide is 1:0.5~2; the volume of water used to disperse the black talc is 10-15 mL / g based on the mass of the black talc; the volume of toluene is 10-30 mL / g based on the mass of the alkalized black talc; and the mass ratio of the alkalized black talc to γ-aminoethylaminopropyltrimethoxysilane is 1:0.5~2.

4. The chitosan-black talc composite according to claim 1, wherein In step S3, the polymerization reaction is stirred at 50° C. for 6 h.

5. The chitosan-black talc composite according to claim 1, wherein The drying in steps S2 and S3 is performed at 60-100°C for 10-24 hours.

6. Use of the chitosan-black talc composite according to claim 1 in preparing a mildew and antibacterial agent for rubber cables.

7. The use according to claim 6, characterized in that The mold inhibited by the mildew and antibacterial agent is one or a mixture of two or more of Aspergillus niger, Aspergillus versicolor, Fusarium spp. or Penicillium funiculosum; the inhibited bacteria include Staphylococcus aureus or Escherichia coli.

8. The use according to claim 6, characterized in that The application is to add the chitosan-black talc compound to a rubber cable raw material to prepare a mildew-proof and antibacterial rubber cable, and the amount of the chitosan-black talc compound added is 0.5-2% of the mass of the rubber cable raw material.

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