Corrosion-resistant flame-retardant cable and preparation process thereof

Abstract

The invention discloses a corrosion-resistant flame-retardant cable and a preparation process thereof, and belongs to the technical field of cables. The corrosion-resistant flame-retardant cable provided by the invention is prepared from the following components in parts by mass: 45 to 55 parts of polyvinyl chloride, 30 to 40 parts of polyphenylene sulfide, 4 to 6 parts of boron nitride nanosheets, 2 to 4 parts of functional filler, 12 to 18 parts of maleic anhydride grafted SEBS (Styrene-Ethylene-Butylene-Styrene), 6 to 10 parts of flame retardant and 0.3 to 0.8 part of initiator. The preparation method comprises the following steps: firstly, uniformly mixing polyvinyl chloride, polyphenylene sulfide, boron nitride nanosheets and functional filler, then adding maleic anhydride grafted SEBS and a flame retardant, and uniformly mixing to obtain a premix; and finally, adding the premix and the dispersing agent into an extruder for extrusion granulation, and cooling, curing and shaping the extruded cable material to obtain the corrosion-resistant flame-retardant cable. According to the corrosion-resistant flame-retardant cable provided by the invention, the corrosion path can be prolonged, the corrosion resistance is improved, a PO. Natural base quenching combustion chain is generated through red phosphorus, the flame propagation rate is greatly reduced, and the flame retardance is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of cables, and in particular relates to a corrosion-resistant and flame-retardant cable and a preparation process thereof. Background Art

[0002] With the rapid development of industry and technology, the performance requirements for cables are becoming increasingly stringent, especially for applications in high-temperature and corrosive environments. While traditional cable sheath materials such as polyvinyl chloride (PVC), chloroprene rubber (CR), chlorosulfonated polyethylene (CSM), and polytetrafluoroethylene (PTFE) offer some protection, they lack corrosion resistance and flame retardancy, making them prone to safety incidents such as electrical leakage and fire.

[0003] Ordinary environmentally friendly polyvinyl chloride cables have poor weather resistance. When used outdoors, they are prone to cracking due to rain, fog, exposure to the sun, etc., and cannot meet the requirements of outdoor use. At the same time, cracking will cause the flame retardant performance of the surface to deteriorate, and the cable has low light transmittance and high smoke density when burning. Once a fire occurs, the cable is easily affected by the flames and spreads, accompanied by a large amount of smoke. If elements such as magnesium, copper, zinc, and iron are added to the cable to improve its performance, local corrosion is likely to occur, such as stress corrosion cracking, layer corrosion, and intergranular corrosion. In summary, existing cables have defects in terms of corrosion resistance and flame retardancy, such as easy cracking resulting in a short service life, easy burning, and inability to flame retardant in time. Further improvement and optimization are needed. It is very necessary to develop a cable that is both corrosion-resistant and has high-efficiency flame retardant properties. Summary of the Invention

[0004] Based on the deficiencies of the prior art, the present invention provides a corrosion-resistant and flame-retardant cable and a preparation process thereof.

[0005] The first aspect of the present invention is to provide a corrosion-resistant and flame-retardant cable, comprising the following components, calculated by weight: 45-55 parts of polyvinyl chloride, 30-40 parts of polyphenylene sulfide, 4-6 parts of boron nitride nanosheets, 2-4 parts of functional filler, 12-18 parts of maleic anhydride grafted SEBS, 6-10 parts of flame retardant, and 0.3-0.8 parts of initiator; Wherein, the functional filler is sulfonated graphene, which is prepared by the following steps: (1) dispersing graphene oxide in an acid solution and refluxing to activate it, then centrifuging to obtain a precipitate, washing the precipitate, and drying it to obtain pretreated graphene oxide; (2) dispersing the pretreated graphene oxide in a p-aminobenzenesulfonic acid solution, performing a hydrothermal reaction under the protection of an inert gas, and filtering and drying to obtain the grafted sulfonic acid group graphene oxide; (3) The grafted sulfonic acid group graphene oxide is dispersed in deionized water, and a reducing agent and a catalyst are added to carry out a reduction reaction. After the reaction is completed, the sulfonated graphene is obtained by drying.

[0006] It should be noted that due to storage and preparation residues, the surface functional groups of industrial-grade graphene oxide are often passivated by metal ions or converted into low-activity ether bonds, making it chemically inert and having low efficiency in direct sulfonation reaction. The present invention uses acid solution for activation treatment to restore the reaction activity of oxygen-containing groups such as carboxyl and hydroxyl groups on its surface. The p-aminobenzenesulfonic acid is thermally cracked at high temperature to produce benzenesulfonyl radicals that attack the oxygen-containing groups, and dehydration condensation forms highly stable sulfonamide bonds. The introduction of inert gas is to avoid oxidative decomposition of benzenesulfonic acid groups and to avoid combustion of graphene oxide in high-temperature oxygen. In addition, since the sulfonation reaction is carried out at high temperature, the graphene oxide lattice is easily destroyed by the strong oxidizing sulfonating agent to form a large amount of sp 3 Therefore, it is necessary to remove excess oxygen-containing groups through a reduction reaction to restore the conductivity of graphene oxide.

[0007] In some embodiments, the acid solution is selected from at least one of hydrochloric acid solution, sodium bisulfate solution, and phosphoric acid solution; the concentration of the p-aminobenzenesulfonic acid solution is 9-10 wt%; the reducing agent is a mixture of L-ascorbic acid and L-cysteine ​​in a mass ratio of 5-7:1; and the catalyst is selected from at least one of ferric chloride and phosphomolybdic acid.

[0008] In some embodiments, the mass ratio of graphene oxide to p-aminobenzenesulfonic acid is 1-3:2-4; the amount of the reducing agent is 1-2 times the mass of the graphene oxide; and the amount of the catalyst is 0.03-0.07% of the mass of the graphene oxide.

[0009] In some embodiments, in step (1), the reflux activation temperature is 88-98°C, the reflux activation time is 1.5-2.5 h, the washing is resuspended with deionized water to a pH of 6-7, the drying temperature is -60 to -40°C, and the drying time is 10-12 h; in step (2), the hydrothermal reaction temperature is 140-160°C, the hydrothermal reaction time is 8-12 h, the drying temperature is -60 to -40°C, and the drying time is 14-16 h; in step (3), the reaction temperature is 75-85°C, and the reaction time is 6-8 h.

[0010] In some embodiments, the flame retardant is coated red phosphorus @MIL-101, which is prepared by the following steps: Step 1: Dispersing chromium trichloride hexahydrate and terephthalic acid in solvent 1, and centrifugally drying after the reaction to obtain the MIL-101 (Cr) carrier; Step 2: Disperse the MIL-101(Cr) carrier and red phosphorus powder in solvent 2, centrifuge and dry to obtain coated red phosphorus@MIL-101.

[0011] In some embodiments, the mass ratio of chromium trichloride hexahydrate to terephthalic acid is 1:0.6-0.7; the mass ratio of MIL-101(Cr) carrier to red phosphorus is 5-6:1; the first solvent is selected from at least one of DMF and NMP; the particle size of the red phosphorus powder is 2-5 μm; and the second solvent is selected from at least one of anhydrous ethanol, isopropanol, and acetone.

[0012] In some embodiments, in the first step, the reaction temperature is 100-120° C., and the reaction time is 5-7 h; in the second step, the dispersion is carried out by stirring at a speed of 250-350 rpm for 2-3 h.

[0013] The second aspect of the present invention is to provide a preparation process of a corrosion-resistant flame-retardant cable, comprising the following steps: S1: uniformly mixing polyvinyl chloride, polyphenylene sulfide, boron nitride nanosheets and functional fillers; S2: Add maleic anhydride grafted SEBS and flame retardant to the S1 mixed system and mix evenly to obtain a premix; S3: adding the premix and dispersant into an extruder for extrusion and granulation, and cooling, solidifying and shaping the extruded cable material to obtain a corrosion-resistant and flame-retardant cable.

[0014] In some embodiments, the initiator is selected from at least one of DCP, BIBP, and DCPD.

[0015] In some embodiments, in S1, the mixing temperature is 60-80°C; in S2, the mixing temperature is 90-110°C.

[0016] Compared with the prior art, the present invention also has the following beneficial effects: 1. The present invention creatively adds sulfonated graphene, -SO3 in the sulfonic acid group - Coulomb repulsion pushes the sheets apart to create stacking space, and hydrogen bonds anchor the sheets on the polymer chains in a directional arrangement, thereby forming densely stacked graphene sheets. Sulfonated graphene is evenly dispersed in the PVC / PPS matrix to form an obstacle, extending the invasion path of the corrosive medium and reducing the acid (H + ), chloride ion (Cl - ), water molecules (H2O), oxygen (O2) and other corrosive media. In addition, the sulfonic acid group can actively capture H + Ion channels are formed to guide the corrosion current to the metal core and slow down the rate of electrical corrosion.

[0017] 2. The present invention creatively incorporates coated red phosphorus @MIL-101 as a flame retardant. The metal organic framework of MIL-101 encapsulates red phosphorus particles within the pores, forming a physical barrier that blocks their contact with oxygen and water, eliminating the risk of spontaneous combustion. When the PVC decomposition temperature is reached, the framework collapses and releases red phosphorus, generating PO· natural radicals that quench the combustion chain, greatly reducing the flame propagation rate and achieving a faster response speed. In addition, red phosphorus can also decompose to form phosphoric acid or polyphosphoric acid, promoting dehydration and carbonization of the material surface to form a heat-insulating and oxygen-isolating layer. The MIL-101 carbon residue can form a ceramic protective layer, greatly increasing the density of the carbon layer, thereby achieving a flame-retardant effect.

[0018] 3. The corrosion-resistant and flame-retardant cable provided by the present invention achieves long-term corrosion resistance through sulfonated graphene, and the red phosphorus @MIL-101 coating gives the cable high flame retardant properties, simultaneously solving the dual risks of corrosion and fire in chemical environments. It is suitable for scenarios such as wires and cables, oil platforms, and chemical pipelines. The present invention also adopts a one-step extrusion molding process to replace traditional multi-stage processing, simplifying the production process. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below with reference to specific embodiments.

[0020] Example 1 A corrosion-resistant and flame-retardant cable comprises the following components, calculated by mass: 50 parts of polyvinyl chloride, 35 parts of polyphenylene sulfide, 5 parts of boron nitride nanosheets, 3 parts of functional filler, 15 parts of maleic anhydride grafted SEBS, 8 parts of flame retardant, and 0.5 parts of initiator DCP.

[0021] The functional filler is sulfonated graphene, which is prepared by the following steps: (1) Graphene oxide was dispersed in a hydrochloric acid solution and refluxed at 95°C for 2 h, then centrifuged to obtain a precipitate, washed with deionized water to a pH of 6-7, and freeze-dried at -50°C for 11 h to obtain pretreated graphene oxide; (2) The pretreated graphene oxide was dispersed in a 10 wt% p-aminobenzenesulfonic acid solution, and the mixture was hydrothermally reacted at 150 °C for 10 h under inert gas protection. After filtration, the mixture was freeze-dried at -50 °C for 15 h to obtain the grafted sulfonic acid-grouped graphene oxide. (3) The grafted sulfonic acid-grouped graphene oxide was dispersed in deionized water, and a reducing agent consisting of a mixture of L-ascorbic acid and L-cysteine ​​in a mass ratio of 6:1 and ferric chloride was added to carry out a reduction reaction at 80°C for 7 h. After the reaction was completed, the sulfonated graphene was obtained by drying.

[0022] Among them, the mass ratio of graphene oxide and p-aminobenzenesulfonic acid is 2:3; the amount of reducing agent used is 1.5 times the mass of graphene oxide; and the amount of catalyst used is 0.05% of the mass of graphene oxide.

[0023] The flame retardant is coated red phosphorus @MIL-101 and is prepared by the following steps: Step 1: Disperse chromium trichloride hexahydrate and terephthalic acid in a mass ratio of 1:0.6 in DMF, react at 110°C for 6 h, and centrifuge to obtain the MIL-101(Cr) carrier; Step 2: The MIL-101(Cr) carrier and red phosphorus powder were dispersed in anhydrous ethanol at a mass ratio of 5:1, stirred and dispersed at 300 rpm for 2.5 h, centrifuged and dried to obtain the coated red phosphorus@MIL-101.

[0024] The above-mentioned corrosion-resistant flame-retardant cable is prepared by the following steps: S1: polyvinyl chloride, polyphenylene sulfide, boron nitride nanosheets and functional fillers were mixed uniformly at 70°C; S2: Add maleic anhydride grafted SEBS and flame retardant to the S1 mixed system and mix them evenly at 100°C to obtain a premix; S3: adding the premix and dispersant into an extruder for extrusion and granulation, and cooling, solidifying and shaping the extruded cable material to obtain a corrosion-resistant and flame-retardant cable.

[0025] Example 2 It is basically the same as Example 1, except that: The corrosion-resistant flame-retardant cable provided in this Example 2 includes the following components, in parts by mass: 55 parts of polyvinyl chloride, 40 parts of polyphenylene sulfide, 6 parts of boron nitride nanosheets, 4 parts of functional filler, 18 parts of maleic anhydride grafted SEBS, 10 parts of flame retardant, and 0.8 parts of initiator BIBP.

[0026] Example 3 It is basically the same as Example 1, except that: The corrosion-resistant flame-retardant cable provided in this Example 3 includes the following components, in parts by mass: 45 parts of polyvinyl chloride, 30 parts of polyphenylene sulfide, 4 parts of boron nitride nanosheets, 2 parts of functional filler, 12 parts of maleic anhydride grafted SEBS, 6 parts of flame retardant, and 0.3 parts of initiator DCPD.

[0027] Example 4 It is basically the same as Example 1, except that: The sulfonated graphene in this embodiment 4 was prepared by the following steps: (1) Graphene oxide was dispersed in a sodium bisulfate solution and refluxed at 98°C for 2.5 h, then the precipitate was centrifuged and washed with deionized water until the pH was 6-7, and then freeze-dried at -60°C for 12 h to obtain pretreated graphene oxide; (2) The pretreated graphene oxide was dispersed in a 10 wt% p-aminobenzenesulfonic acid solution, and the mixture was hydrothermally reacted at 160 °C for 12 h under inert gas protection. After filtration, the mixture was freeze-dried at -60 °C for 16 h to obtain the grafted sulfonic acid-grouped graphene oxide. (3) The grafted sulfonic acid-grouped graphene oxide was dispersed in deionized water, and a reducing agent consisting of a mixture of L-ascorbic acid and L-cysteine ​​in a mass ratio of 7:1 and phosphomolybdic acid were added to carry out a reduction reaction at 85°C for 8 h. After the reaction was completed, the sulfonated graphene was obtained by drying.

[0028] Among them, the mass ratio of graphene oxide and p-aminobenzenesulfonic acid is 3:4; the amount of reducing agent is twice the mass of graphene oxide; and the amount of catalyst is 0.07% of the mass of graphene oxide.

[0029] The coated red phosphorus @MIL-101 in Example 4 was prepared by the following steps: Step 1: Disperse chromium trichloride hexahydrate and terephthalic acid in a mass ratio of 1:0.7 in NMP, react at 120°C for 7 h, and centrifuge to obtain the MIL-101(Cr) carrier; Step 2: The MIL-101(Cr) carrier and red phosphorus powder were dispersed in isopropanol at a mass ratio of 6:1, stirred and dispersed at 350 rpm for 3 h, centrifuged and dried to obtain the coated red phosphorus@MIL-101.

[0030] Example 5 It is basically the same as Example 1, except that: The sulfonated graphene in this embodiment 5 was prepared by the following steps: (1) Graphene oxide was dispersed in a phosphoric acid solution and refluxed at 88°C for 1.5 h, then the precipitate was centrifuged, washed with deionized water to a pH of 6-7, and freeze-dried at -40°C for 10 h to obtain pretreated graphene oxide; (2) The pretreated graphene oxide was dispersed in a 9 wt% p-aminobenzenesulfonic acid solution, and the mixture was hydrothermally reacted at 140 °C for 8 h under inert gas protection. After filtration, the mixture was freeze-dried at -40 °C for 14 h to obtain the grafted sulfonic acid-grouped graphene oxide. (3) The grafted sulfonic acid-grouped graphene oxide was dispersed in deionized water, and a reducing agent consisting of a mixture of L-ascorbic acid and L-cysteine ​​in a mass ratio of 5:1 and ferric chloride was added to carry out a reduction reaction at 75°C for 6 h. After the reaction was completed, the sulfonated graphene was obtained by drying.

[0031] The mass ratio of graphene oxide to p-aminobenzenesulfonic acid is 1:2; the amount of reducing agent is 1 times the mass of graphene oxide; and the amount of catalyst is 0.03% of the mass of graphene oxide.

[0032] The coated red phosphorus @MIL-101 in Example 5 was prepared by the following steps: Step 1: Disperse chromium trichloride hexahydrate and terephthalic acid in a mass ratio of 1:0.6 in DMF, react at 100°C for 5 h, and centrifuge to obtain the MIL-101(Cr) carrier; Step 2: The MIL-101(Cr) carrier and red phosphorus powder were dispersed in acetone at a mass ratio of 5:1, stirred and dispersed at 250 rpm for 2 h, centrifuged and dried to obtain the coated red phosphorus@MIL-101.

[0033] Comparative Example 1 The method is basically the same as Example 1, except that the sulfonated graphene is replaced by the same amount of graphene.

[0034] Comparative Example 2 The method is basically the same as Example 1, except that the coated red phosphorus @MIL-101 is replaced with the same amount of red phosphorus.

[0035] Comparative Example 3 The method is basically the same as Example 1, except that the coated red phosphorus@MIL-101 is replaced with the same amount of red phosphorus+MIL-101 blend.

[0036] The red phosphorus + MIL-101 blend is prepared by the following steps: equal amounts of red phosphorus powder and MIL-101 powder are dry-milled and mixed.

[0037] In order to verify that the corrosion-resistant and flame-retardant cables provided by the present invention have excellent corrosion resistance and flame retardancy, the cables prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to performance tests. The test results are shown in Table 1.

[0038] Flame retardant performance test: flame retardant time is tested according to GB / T2918-1996 standard; oxidation index is tested according to GB / T 2406-1993 standard; Corrosion resistance test: An aging test was conducted in which the cable material was aged at 80°C for 14 days to test the tensile strength and elongation at break of the cable. The tensile strength was tested in accordance with GB / T 1040.3-2006; the elongation at break was tested in accordance with GB / T1040.3-2006.

[0039] Table 1 As can be seen from Table 1, Examples 1-5 all exhibit excellent flame retardancy, corrosion resistance, and mechanical properties. In conjunction with the comparative examples, it can be found that comparative example 1 does not add sulfonated graphene, resulting in a faster corrosion rate. Although an equal amount of graphene is added, the unsulfonated graphene easily agglomerates in the polymer, and there is no sulfonic acid group and proton channels cannot be constructed, resulting in loss of electrochemical anti-corrosion function. Within 14 days, the mechanical properties show a significant decrease; comparative example 2 replaces the coated red phosphorus @ MIL-101 with an equal amount of red phosphorus, and comparative example 3 replaces the coated red phosphorus @ MIL-101 with an equal amount of red phosphorus + MIL-101 blend. Since red phosphorus is not wrapped, the area exposed to oxygen increases, making it easy to release during processing and easily dispersed unevenly. It is unable to form a ceramic protective layer in coordination with MIL-101 in a timely manner, resulting in a significant decrease in the flame retardant properties of the cable.

[0040] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A corrosion-resistant flame-retardant cable, characterized in that: The composition comprises the following components in parts by mass: 45-55 parts of polyvinyl chloride, 30-40 parts of polyphenylene sulfide, 4-6 parts of boron nitride nanosheets, 2-4 parts of functional filler, 12-18 parts of maleic anhydride grafted SEBS, 6-10 parts of flame retardant, and 0.3-0.8 parts of initiator; Wherein, the functional filler is sulfonated graphene, which is prepared by the following steps: (1) dispersing graphene oxide in an acid solution and refluxing to activate it, then centrifuging to obtain a precipitate, washing the precipitate, and drying it to obtain pretreated graphene oxide; (2) dispersing the pretreated graphene oxide in a p-aminobenzenesulfonic acid solution, performing a hydrothermal reaction under the protection of an inert gas, and filtering and drying to obtain the grafted sulfonic acid group graphene oxide; (3) The grafted sulfonic acid group graphene oxide is dispersed in deionized water, and a reducing agent and a catalyst are added to carry out a reduction reaction. After the reaction is completed, the sulfonated graphene is obtained by drying.

2. The corrosion-resistant flame-retardant cable according to claim 1, characterized in that: The acid solution is selected from at least one of hydrochloric acid solution, sodium bisulfate solution, and phosphoric acid solution; the concentration of the p-aminobenzenesulfonic acid solution is 9-10 wt%; the reducing agent is a mixture of L-ascorbic acid and L-cysteine ​​in a mass ratio of 5-7:1; and the catalyst is selected from at least one of ferric chloride and phosphomolybdic acid.

3. The corrosion-resistant flame-retardant cable according to claim 2, characterized in that: The mass ratio of the graphene oxide to the p-aminobenzenesulfonic acid is 1-3:2-4; the amount of the reducing agent is 1-2 times the mass of the graphene oxide; and the amount of the catalyst is 0.03-0.07% of the mass of the graphene oxide.

4. The corrosion-resistant flame-retardant cable according to claim 1, characterized in that: In the step (1), the reflux activation temperature is 88-98°C, the reflux activation time is 1.5-2.5 h, the washing is resuspended with deionized water to a pH of 6-7, the drying temperature is -60 to -40°C, and the drying time is 10-12 h; in the step (2), the hydrothermal reaction temperature is 140-160°C, the hydrothermal reaction time is 8-12 h, the drying temperature is -60 to -40°C, and the drying time is 14-16 h; in the step (3), the reaction temperature is 75-85°C, and the reaction time is 6-8 h.

5. The corrosion-resistant flame-retardant cable according to claim 1, characterized in that: The flame retardant is coated red phosphorus @MIL-101 and is prepared by the following steps: Step 1: Dispersing chromium trichloride hexahydrate and terephthalic acid in solvent 1, and centrifugally drying after the reaction to obtain the MIL-101 (Cr) carrier; Step 2: Disperse the MIL-101(Cr) carrier and red phosphorus powder in solvent 2, centrifuge and dry to obtain coated red phosphorus@MIL-101.

6. The corrosion-resistant flame-retardant cable according to claim 5, characterized in that: The mass ratio of the chromium chloride hexahydrate to the terephthalic acid is 1:0.6-0.7; the mass ratio of the MIL-101 (Cr) carrier to the red phosphorus is 5-6:1; the first solvent is selected from at least one of DMF and NMP; the particle size of the red phosphorus powder is 2-5 μm; and the second solvent is selected from at least one of anhydrous ethanol, isopropyl alcohol, and acetone.

7. The corrosion-resistant flame-retardant cable according to claim 5, characterized in that: In the first step, the reaction temperature is 100-120° C. and the reaction time is 5-7 h. In the second step, the dispersion is carried out by stirring at a speed of 250-350 rpm for 2-3 h.

8. A process for preparing the corrosion-resistant flame-retardant cable according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: uniformly mixing polyvinyl chloride, polyphenylene sulfide, boron nitride nanosheets and functional fillers; S2: Add maleic anhydride grafted SEBS and flame retardant to the S1 mixed system and mix evenly to obtain a premix; S3: adding the premix and dispersant into an extruder for extrusion and granulation, and cooling, solidifying and shaping the extruded cable material to obtain a corrosion-resistant and flame-retardant cable.

9. The process for preparing the corrosion-resistant flame-retardant cable according to claim 8, characterized in that: The initiator is selected from at least one of DCP, BIBP and DCPD.

10. The preparation process of the corrosion-resistant flame-retardant cable according to claim 8, characterized in that: In the S1, the mixing temperature is 60-80°C; in the S2, the mixing temperature is 90-110°C.

Images