Polyurethane composite material for mining cable as well as preparation method and application of polyurethane composite material
Through the molecular design of polyurethane prepolymer and grafted functional filler and the synergistic effect of borate bonds and thiol groups, a hydrophobic-hydrophilic two-phase network structure is constructed, which solves the problem of insufficient self-repair efficiency of mining cables in high humidity and complex environments, achieves the unity of high water absorption and expansion and mechanical strength, and improves the long-term sealing reliability of the material.
Patent Information
- Application Number
- CN202510728600.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-03
- Publication Date
- 2025-09-16
AI Technical Summary
In the high humidity, strong vibration and complex geological environment of mining cables, existing polyurethane materials are difficult to balance high water absorption and expansion with mechanical strength, and the self-repair efficiency is insufficient, resulting in moisture penetration and insulation failure.
Through the molecular design of polyurethane prepolymer and grafted functional filler, combined with the synergistic effect of borate bonds and thiol groups, a hydrophobic-hydrophilic two-phase network structure is constructed. Surface composite modification technology and multi-scale filler design are used to achieve self-repair of the material in humid and low-temperature environments underground.
It achieves the unity of high water absorption and expansion performance and mechanical strength. The material can repair itself after damage, significantly improving the long-term sealing reliability of the sheath, avoiding phase separation, and meeting the long-term sealing requirements of mining cables under complex working conditions.
Smart Images
Figure CN120648212A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of cable protection materials, and in particular relates to a polyurethane composite material for mining cables, a preparation method and an application thereof. Background Art
[0002] Mining cables are subject to long-term exposure to high humidity, strong vibration, and complex geological environments, placing extremely stringent demands on the waterproof sealability and mechanical durability of the sheath material. Traditional cable shielding materials, often made of chlorinated polyethylene or nitrile rubber systems, offer some water-blocking properties but suffer from low water absorption and expansion rates and poor dynamic fatigue resistance. Especially in tunnel water seepage conditions, existing materials, due to their low water absorption and expansion rates, are unable to effectively seal microcracks within the cable, leading to longitudinal water penetration and insulation failure.
[0003] Polyurethane materials, due to their strong designability and excellent wear resistance, have been explored in recent years for use in cable protection. Invention Publication No. CN105384909A discloses a method for synthesizing composite polyurethane for cable applications. This invention improves the mechanical properties and stability of polyurethane through composite components and inorganic fillers, but it still fails to effectively address the key technical bottlenecks of polyurethane materials in mining applications: the introduction of hydrophobic monomers such as methyl methacrylate and styrene inhibits the material's water absorption and expansion, making it difficult for a single network system to balance high water absorption and expansion with mechanical strength. Furthermore, the curing process relies on dibenzoyl peroxide to initiate chemical crosslinking, resulting in a traditional covalent bond network that lacks a dynamic reversible bonding mechanism. Consequently, the material cannot achieve self-repair in the low-temperature and humid underground environment after damage. Summary of the Invention
[0004] To address the existing challenges of polyurethanes in achieving both high water swelling and mechanical strength, as well as insufficient self-repair efficiency after damage, the present invention provides a polyurethane composite material for mining cables, its preparation method, and its application. Through the molecular design of a polyurethane prepolymer and a grafted functional filler, the present invention achieves high water swelling while effectively maintaining the mechanical strength of the material matrix. The synergistic effect of borate bonds and thiol groups enables the material to autonomously repair damage in humid and low-temperature environments underground, significantly improving the long-term sealing reliability of the sheath. A surface composite modification process and multi-scale filler design are employed to achieve uniform dispersion of nano-reinforced materials within the polyurethane matrix and stable interfacial bonding.
[0005] To achieve the above objectives, the present invention provides the following technical solutions:
[0006] A polyurethane composite material for mining cables, comprising the following components in parts by weight: 100 parts of polyoxypropylene glycol, 25-30 parts of toluene diisocyanate, 15-20 parts of grafted sodium polyacrylate polyurethane, 5-8 parts of nano-montmorillonite modified cellulose, 3-5 parts of borate bond modified polysiloxane, 2-3 parts of polyethylene glycol thiol, 0.05-0.1 part of catalyst, 3-5 parts of plasticizer, 0.1-0.3 part of defoamer, and 0.2-0.5 part of antioxidant.
[0007] Preferably, the NCO content of the toluene diisocyanate is 6-8%.
[0008] Preferably, the catalyst is dibutyltin dilaurate.
[0009] Preferably, the plasticizer is polyethylene glycol.
[0010] Preferably, the defoaming agent is a silicone defoaming agent.
[0011] Preferably, the antioxidant is one or more of 1010 antioxidant or butylated hydroxytoluene.
[0012] The present invention also provides a method for preparing a polyurethane composite material for mining cables, comprising the following steps: (1) reacting polyoxypropylene glycol and toluene diisocyanate in the presence of a catalyst to prepare a polyurethane prepolymer; (2) mixing grafted sodium polyacrylate polyurethane with nano-montmorillonite modified cellulose to perform surface composite modification to obtain a modified functional filler; (3) the polyurethane prepolymer prepared in step (1), the modified functional filler prepared in step (2), the borate bond-modified polysiloxane and the polyethylene glycol thiol are put into a high-speed mixer for mixing, and then the remaining materials are added into a low-speed stirring tank for homogenization; (4) The mixed material is injected into a mold after vacuum degassing, and is formed through a step curing and post-curing process to obtain a polyurethane composite material for mining cables.
[0013] Preferably, the reaction temperature in step (1) is 70-80° C., and the reaction time is 2-3 h.
[0014] Preferably, the step curing process in step (4) is as follows: first curing at 80°C for 1 to 3 hours, then heating to 120°C for curing for 1 to 2 hours; and the post-curing process is standing and curing in a 25°C environment for 12 to 36 hours.
[0015] The present invention also provides a tensile-resistant and corrosion-resistant mining cable, comprising: Three wire cores are evenly distributed in a 120° circle, and each wire core is composed of a conductor 1, an aramid fiber water-blocking layer 2 wrapped around the conductor, an inner insulating layer 3, an outer insulating layer 4 and a semi-conductive water-blocking layer 5 from the inside to the outside; the outer sides of the three wire cores are sequentially coated with a filling layer 6, a wrapping layer 7, an armor layer 8 and an outer sheath layer 9; the filling layer 6 uses the above-mentioned polyurethane composite material for mining cables.
[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) Through the molecular design of polyurethane prepolymer and grafted functional filler, a hydrophobic-hydrophilic dual-phase network structure is constructed, which effectively maintains the mechanical strength of the material matrix while achieving high water absorption and expansion performance, overcoming the defect of traditional materials that the mechanical properties of traditional materials decrease rapidly after water absorption; (2) Through the synergistic effect of borate bonds and thiol groups, a dynamic cross-linked network with environmental responsiveness is formed, which enables the material to autonomously repair damage in the humid and low-temperature environment underground, significantly improving the long-term sealing reliability of the sheath; (3) The surface composite modification process and multi-scale filler design are used to achieve uniform dispersion of nano-reinforced materials in the polyurethane matrix and stable interface bonding, avoiding phase separation during processing and use. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the main cross-sectional structure of a tensile-resistant and corrosion-resistant mining cable proposed by the present invention.
[0018] In the figure: 1. Conductor; 2. Aramid fiber water-blocking layer; 3. Inner insulation layer; 4. Outer insulation layer; 5. Semiconductor water-blocking layer; 6. Filling layer; 7. Wrapping layer; 8. Armor layer; 9. Outer sheath layer. DETAILED DESCRIPTION
[0019] The present invention will be further described below with reference to specific embodiments.
[0020] Example 1
[0021] This embodiment provides a total polyurethane composite material formula for mining cables, comprising the following components in parts by weight: 100 parts of polyoxypropylene glycol, 25-30 parts of toluene diisocyanate, 15-20 parts of grafted sodium polyacrylate polyurethane, 5-8 parts of nano-montmorillonite modified cellulose, 3-5 parts of borate bond modified polysiloxane, 2-3 parts of polyethylene glycol thiol, 0.05-0.1 part of a catalyst, 3-5 parts of a plasticizer, 0.1-0.3 parts of a defoaming agent, and 0.2-0.5 parts of an antioxidant.
[0022] In some preferred embodiments, the NCO content of the toluene diisocyanate is 6-8%. The technical benefit lies in precisely controlling the isocyanate group content, optimizing the balance between the crosslinking density and segment flexibility of the polyurethane prepolymer, and enabling the material to form a stable three-dimensional network structure during water absorption and expansion. This ensures volume stability under high expansion rates while avoiding the risk of brittle fracture caused by excessive crosslinking.
[0023] In some preferred embodiments, the catalyst is dibutyltin dilaurate. Its technical effect is that the catalyst selectively accelerates the reaction rate between isocyanate and hydroxyl groups, inhibits side reactions, ensures uniform molecular weight distribution during the prepolymer synthesis stage, and provides a structurally regular basic framework for subsequent dynamic cross-linking network construction.
[0024] In some preferred embodiments, the plasticizer is polyethylene glycol. The technical benefit lies in utilizing the polar segments of polyethylene glycol to form hydrogen bonds with the polyurethane matrix, which not only improves the material's processing fluidity but also alleviates internal stress caused by water absorption and expansion through a dynamic plasticizing effect, preventing interfacial delamination after multiple wet-dry cycles.
[0025] In some preferred embodiments, the defoaming agent is a silicone defoaming agent. Its technical benefits include reducing the surface tension of bubbles in the mixed system, rapidly dissolving bubbles entrapped during stirring, preventing the formation of microporous defects within the cured material, and ensuring the tightness and long-term sealing reliability of the jacket layer under high-pressure water seepage conditions.
[0026] In some preferred embodiments, the antioxidant is one or more of 1010 antioxidant or butylated hydroxytoluene. This has the technical effect of synergistically inhibiting the oxidative degradation of polyurethane molecular chains during high-temperature processing and in the hot and humid environment of underground mines. By capturing free radicals and decomposing peroxides, the chemical stability of the dynamic cross-linked network is maintained, extending the service life of the material.
[0027] This embodiment also provides a method for preparing a polyurethane composite material for mining cables, comprising the following steps: (1) reacting polyoxypropylene glycol and toluene diisocyanate in the presence of a catalyst to prepare a polyurethane prepolymer; (2) mixing grafted sodium polyacrylate polyurethane with nano-montmorillonite modified cellulose to perform surface composite modification to obtain a modified functional filler; (3) the polyurethane prepolymer prepared in step (1), the modified functional filler prepared in step (2), the borate bond-modified polysiloxane and the polyethylene glycol thiol are put into a high-speed mixer for mixing, and then the remaining materials are added into a low-speed stirring tank for homogenization; (4) The mixed material is injected into a mold after vacuum degassing, and is formed through a step curing and post-curing process to obtain a polyurethane composite material for mining cables. Its technical effect is that the dynamic cross-linking network is accurately constructed through step-by-step synthesis and in-situ compounding of functional fillers. The polyurethane prepolymer serves as a flexible matrix skeleton and forms a multi-level interface bond with the surface-composite modified functional filler; the vacuum degassing process eliminates internal defects, and the step curing process guides the orderly cross-linking of borate bonds and thiol groups, ultimately forming a three-dimensional network structure with high elasticity, self-healing properties and gradient water absorption properties, which meets the long-term sealing requirements of mining cables for sheath materials under complex working conditions.
[0028] In some preferred implementation cases, the reaction temperature in step (1) is 70-80°C, and the reaction time is 2-3 hours. The technical effect is that at a reaction temperature of 70-80°C, the addition reaction rate of isocyanate and polyol and the suppression of side reactions reach an optimal balance, and the 2-3 hour reaction window ensures a uniform molecular weight distribution of the prepolymer, providing a low-viscosity, highly reactive base material for subsequent dynamic crosslinking, and avoiding the risk of yellowing or gelation of the prepolymer caused by high temperature.
[0029] In some preferred implementation cases, the step curing process in step (4) is specifically as follows: first curing at 80°C for 1-3 hours, then heating to 120°C for curing for 1-2 hours; and the post-curing process is to stand and mature in a 25°C environment for 12-36 hours. The technical effect is that pre-curing at 80°C promotes the initial cross-linking of borate bonds to form a reversible network framework; high-temperature curing at 120°C activates the thiol-ene click reaction to construct permanent cross-linking points to enhance network stability; and post-curing at 25°C for 12-36 hours eliminates internal stress through molecular chain relaxation and dynamic bond rearrangement, allowing the material to maintain shape memory recovery within a temperature range of -40°C to 125°C.
[0030] This embodiment also provides a tensile and corrosion-resistant mining cable, the main cross-sectional structure of which is as follows: Figure 1 As shown, including:
[0031] Three wire cores are evenly spaced in a 120° circle. Each wire core is composed, from the inside to the outside, of a conductor 1, an aramid fiber water-blocking layer 2 wrapped around the conductor, an inner insulating layer 3, an outer insulating layer 4, and a semi-conductive water-blocking layer 5. The outer sides of the three wire cores are sequentially coated with a filling layer 6, a wrapping layer 7, an armor layer 8, and an outer sheath layer 9. The filling layer 6 uses the above-mentioned polyurethane composite material for mining cables. Its technical effect is that, by utilizing the shape memory effect and water absorption and expansion properties of the polyurethane composite material for mining cables provided by the present invention, when the cable is squeezed and deformed by external force, the filling layer absorbs mechanical energy through molecular chain rearrangement. When water penetrates, the ionic groups in the grafted sodium polyacrylate polyurethane induce controllable expansion, synergistically acting with the interlayer confinement effect of the nano-montmorillonite to achieve self-regulating sealing protection. At the same time, the dynamic reversible properties of the borate bonds enable the material to maintain a high elastic recovery rate during dry-wet cycles.
[0032] Example 2
[0033] This embodiment provides a polyurethane composite material formulation for mining cables, comprising the following components in parts by weight: 100 parts of polyoxypropylene glycol, 25 parts of toluene diisocyanate (NCO content 7%), 15 parts of grafted sodium polyacrylate polyurethane, 6 parts of nano-montmorillonite modified cellulose, 4 parts of borate bond modified polysiloxane, 2 parts of polyethylene glycol thiol, 0.1 parts of dibutyltin dilaurate, 5 parts of polyethylene glycol, 0.2 parts of silicone defoamer, and 0.4 parts of dibutylhydroxytoluene.
[0034] This embodiment also provides a method for preparing a polyurethane composite material for mining cables, comprising the following steps: (1) Polyoxypropylene glycol and toluene diisocyanate were mixed in proportion, dibutyltin dilaurate was added as a catalyst, and the mixture was reacted at 75° C. for 2 h to prepare a polyurethane prepolymer; (2) Grafted sodium polyacrylate polyurethane and nano-montmorillonite modified cellulose were mixed and placed in a high-speed mixer, mixed at 900 rpm at 65°C for 30 minutes; then transferred to a ball mill, zirconia ball milling beads were added, and ball milling was carried out at 300 rpm for 2 hours to obtain a modified functional filler; (3) putting the polyurethane prepolymer prepared in step (1), the modified functional filler prepared in step (2), the borate bond-modified polysiloxane and the polyethylene glycol thiol into a planetary high-speed mixer, controlling the temperature at 40° C., the rotation speed at 2000 rpm, and mixing for 5 minutes to form a uniform paste; then transferring the mixture to a low-speed stirring tank, adding a plasticizer, a defoaming agent and an antioxidant, and homogenizing at 15 rpm for 20 minutes to obtain a mixed material; (4) The mixed material is injected into the mold after vacuum degassing treatment, first cured at 80°C for 2 hours, then heated to 120°C for curing for 1 hour; and allowed to stand and mature at 25°C for 24 hours to obtain a polyurethane composite material for mining cables.
[0035] This embodiment also provides a tensile-resistant and corrosion-resistant mining cable, comprising: Three wire cores are evenly distributed in a 120° circle, each core comprising, from the inside to the outside, a conductor 1, an aramid fiber water-blocking layer 2 wrapped around the conductor, an inner insulating layer 3, an outer insulating layer 4, and a semi-conductive water-blocking layer 5; the outer sides of the three wire cores are sequentially coated with a filling layer 6, a wrapping layer 7, an armor layer 8, and an outer sheath layer 9; The conductor 1 is made of galvanized copper; the inner insulation layer 3 is made of XLPE material; the outer insulation layer 4 is made of CR material; the filling layer 6 is made of the above-mentioned polyurethane composite material for mining cables; the wrapping layer 7 is made of aluminum-plastic composite tape with an overlap rate of 25%; the armor layer 8 is woven with aramid fiber; and the outer sheath layer 9 is made of PU, capsaicin and glass fiber.
[0036] Example 3
[0037] This embodiment provides a polyurethane composite material formulation for mining cables, comprising the following components in parts by weight: 100 parts of polyoxypropylene glycol, 28 parts of toluene diisocyanate (NCO content 7%), 15 parts of grafted sodium polyacrylate polyurethane, 8 parts of nano-montmorillonite modified cellulose, 4 parts of borate bond modified polysiloxane, 2 parts of polyethylene glycol thiol, 0.1 parts of dibutyltin dilaurate, 5 parts of polyethylene glycol, 0.2 parts of silicone defoamer, and 0.4 parts of dibutylhydroxytoluene.
[0038] This embodiment also provides a method for preparing a polyurethane composite material for mining cables, comprising the following steps: (1) Polyoxypropylene glycol and toluene diisocyanate were mixed in proportion, dibutyltin dilaurate was added as a catalyst, and the mixture was reacted at 75° C. for 2 h to prepare a polyurethane prepolymer; (2) Grafted sodium polyacrylate polyurethane and nano-montmorillonite modified cellulose were mixed and placed in a high-speed mixer, mixed at 900 rpm at 65°C for 30 minutes; then transferred to a ball mill, zirconia ball milling beads were added, and ball milling was carried out at 300 rpm for 2 hours to obtain a modified functional filler; (3) putting the polyurethane prepolymer prepared in step (1), the modified functional filler prepared in step (2), the borate bond-modified polysiloxane and the polyethylene glycol thiol into a planetary high-speed mixer, controlling the temperature at 40° C., the rotation speed at 2000 rpm, and mixing for 5 minutes to form a uniform paste; then transferring the mixture to a low-speed stirring tank, adding a plasticizer, a defoaming agent and an antioxidant, and homogenizing at 15 rpm for 20 minutes to obtain a mixed material; (4) The mixed material is injected into the mold after vacuum degassing treatment, first cured at 80°C for 2 hours, then heated to 120°C for curing for 1 hour; and allowed to stand and mature at 25°C for 24 hours to obtain a polyurethane composite material for mining cables.
[0039] This embodiment also provides a tensile-resistant and corrosion-resistant mining cable, comprising: Three wire cores are evenly distributed in a 120° circle, each core comprising, from the inside to the outside, a conductor 1, an aramid fiber water-blocking layer 2 wrapped around the conductor, an inner insulating layer 3, an outer insulating layer 4, and a semi-conductive water-blocking layer 5; the outer sides of the three wire cores are sequentially coated with a filling layer 6, a wrapping layer 7, an armor layer 8, and an outer sheath layer 9; The conductor 1 is made of galvanized copper; the inner insulation layer 3 is made of XLPE material; the outer insulation layer 4 is made of CR material; the filling layer 6 is made of the above-mentioned polyurethane composite material for mining cables; the wrapping layer 7 is made of aluminum-plastic composite tape with an overlap rate of 25%; the armor layer 8 is woven with aramid fiber; and the outer sheath layer 9 is made of PU, capsaicin and glass fiber.
[0040] Comparative Example 1
[0041] The difference between this comparative example and Example 2 is that the polyurethane used in this comparative example is not grafted with sodium polyacrylate.
[0042] This comparative example provides a formula of a polyurethane composite material for mining cables, comprising the following components in parts by weight: 100 parts of polyoxypropylene glycol, 25 parts of toluene diisocyanate (NCO content 7%), 15 parts of polyurethane, 6 parts of nano-montmorillonite modified cellulose, 4 parts of borate bond modified polysiloxane, 2 parts of polyethylene glycol thiol, 0.1 parts of dibutyltin dilaurate, 5 parts of polyethylene glycol, 0.2 parts of silicone defoamer, and 0.4 parts of dibutylhydroxytoluene.
[0043] This comparative example also provides a method for preparing a polyurethane composite material for mining cables, comprising the following steps: (1) Polyoxypropylene glycol and toluene diisocyanate were mixed in proportion, dibutyltin dilaurate was added as a catalyst, and the mixture was reacted at 75° C. for 2 h to prepare a polyurethane prepolymer; (2) The polyurethane and the nano-montmorillonite modified cellulose were mixed and put into a high-speed mixer, and mixed at 65° C. and 900 rpm for 30 minutes; then the mixture was transferred to a ball mill, zirconia ball milling beads were added, and the mixture was ball milled at 300 rpm for 2 hours to obtain a modified functional filler; (3) The polyurethane prepolymer prepared in step (1), the modified functional filler prepared in step (2), the borate bond modified polysiloxane and the polyethylene glycol thiol were put into a planetary high-speed mixer, the temperature was controlled at 40° C., the speed was 2000 rpm, and the mixing time was 5 minutes to form a uniform paste; then the mixture was transferred to a low-speed stirring tank, a plasticizer, a defoamer and an antioxidant were added, and the mixture was homogenized at 15 rpm for 20 minutes to obtain a mixed material; (4) The mixed material is injected into the mold after vacuum degassing treatment, first cured at 80°C for 2 hours, then heated to 120°C for curing for 1 hour; and allowed to stand and mature at 25°C for 24 hours to obtain a polyurethane composite material for mining cables.
[0044] This comparative example also provides a tensile-resistant and corrosion-resistant mining cable, comprising: Three wire cores are evenly distributed in a 120° circle, each core comprising, from the inside to the outside, a conductor 1, an aramid fiber water-blocking layer 2 wrapped around the conductor, an inner insulating layer 3, an outer insulating layer 4, and a semi-conductive water-blocking layer 5; the outer sides of the three wire cores are sequentially coated with a filling layer 6, a wrapping layer 7, an armor layer 8, and an outer sheath layer 9; The conductor 1 is made of galvanized copper; the inner insulation layer 3 is made of XLPE material; the outer insulation layer 4 is made of CR material; the filling layer 6 is made of the above-mentioned polyurethane composite material for mining cables; the wrapping layer 7 is made of aluminum-plastic composite tape with an overlap rate of 25%; the armor layer 8 is woven with aramid fiber; and the outer sheath layer 9 is made of PU, capsaicin and glass fiber.
[0045] Comparative Example 2
[0046] The difference between this comparative example and Example 2 is that this comparative example uses polysiloxane instead of borate bond-modified polysiloxane.
[0047] This comparative example provides a formula of a polyurethane composite material for mining cables, comprising the following components in parts by weight: 100 parts of polyoxypropylene glycol, 25 parts of toluene diisocyanate (NCO content 7%), 15 parts of grafted sodium polyacrylate polyurethane, 6 parts of nano-montmorillonite modified cellulose, 4 parts of polysiloxane, 2 parts of polyethylene glycol thiol, 0.1 parts of dibutyltin dilaurate, 5 parts of polyethylene glycol, 0.2 parts of silicone defoamer, and 0.4 parts of dibutylhydroxytoluene.
[0048] This comparative example also provides a method for preparing a polyurethane composite material for mining cables, comprising the following steps: (1) Polyoxypropylene glycol and toluene diisocyanate were mixed in proportion, dibutyltin dilaurate was added as a catalyst, and the mixture was reacted at 75° C. for 2 h to prepare a polyurethane prepolymer; (2) Grafted sodium polyacrylate polyurethane and nano-montmorillonite modified cellulose were mixed and placed in a high-speed mixer, mixed at 900 rpm at 65°C for 30 minutes; then transferred to a ball mill, zirconia ball milling beads were added, and ball milling was carried out at 300 rpm for 2 hours to obtain a modified functional filler; (3) putting the polyurethane prepolymer prepared in step (1), the modified functional filler prepared in step (2), polysiloxane and polyethylene glycol thiol into a planetary high-speed mixer, controlling the temperature at 40° C., the rotation speed at 2000 rpm, and mixing for 5 minutes to form a uniform paste; then transferring the mixture to a low-speed stirring tank, adding a plasticizer, a defoamer, and an antioxidant, and homogenizing at 15 rpm for 20 minutes to obtain a mixed material; (4) The mixed material is injected into the mold after vacuum degassing treatment, first cured at 80°C for 2 hours, then heated to 120°C for curing for 1 hour; and allowed to stand and mature at 25°C for 24 hours to obtain a polyurethane composite material for mining cables.
[0049] This comparative example also provides a tensile-resistant and corrosion-resistant mining cable, comprising: Three wire cores are evenly distributed in a 120° circle, each core comprising, from the inside to the outside, a conductor 1, an aramid fiber water-blocking layer 2 wrapped around the conductor, an inner insulating layer 3, an outer insulating layer 4, and a semi-conductive water-blocking layer 5; the outer sides of the three wire cores are sequentially coated with a filling layer 6, a wrapping layer 7, an armor layer 8, and an outer sheath layer 9; The conductor 1 is made of galvanized copper; the inner insulation layer 3 is made of XLPE material; the outer insulation layer 4 is made of CR material; the filling layer 6 is made of the above-mentioned polyurethane composite material for mining cables; the wrapping layer 7 is made of aluminum-plastic composite tape with an overlap rate of 25%; the armor layer 8 is woven with aramid fiber; and the outer sheath layer 9 is made of PU, capsaicin and glass fiber.
[0050] Test example
[0051] The water absorption and sealing performance and dynamic self-repairing performance of the polyurethane composite materials for mining cables prepared using the formulations and preparation methods of Examples 2 to 3 and Comparative Examples 1 to 2 were tested, and the results are shown in Table 1.
[0052] Table 1.
[0053] It can be seen from the performance comparison data that the polyurethane composite material for mining cables prepared using the technical solution of the present invention shows significant advantages in core performance indicators such as water absorption and sealing, self-repairing and mechanical retention.
[0054] Comparative Example 1, which did not use grafted sodium polyacrylate polyurethane, showed significant decreases in both water absorption and swelling performance and mechanical strength after expansion. This indicates that the ionic hydrophilic groups in the grafted sodium polyacrylate polyurethane significantly enhance water absorption efficiency through an osmotic pressure effect, and that their synergistic effect with the nano-montmorillonite-modified cellulose forms a high-strength three-dimensional framework, significantly improving the compressive resistance of the expanded material.
[0055] In Comparative Example 2, replacing borate-modified polysiloxane with conventional polysiloxane resulted in a significant decrease in self-repair efficiency and mechanical retention after repair. This demonstrates that the dynamically reversible nature of borate bonds enables efficient self-repair through molecular reconstruction in a humid environment. This, combined with the stress-responsive mechanism of polyethylene glycol thiol, forms a dual repair network, ensuring stable recovery of material performance after damage.
[0056] In summary, the present invention constructs a gradient water absorption network to enable the hydrophilic / hydrophobic microphase separation structure to synergistically achieve the unity of high expansion rate and high strength, uses a dual-mechanism response to break through the bottleneck of self-repair technology in low-temperature environments, and effectively suppresses the phase separation phenomenon by finely dispersing nanofillers.
[0057] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.
Claims
1. A polyurethane composite material for mining cables, characterized in that: Contains the following components in parts by weight: Polyoxypropylene glycol: 100 parts; toluene diisocyanate: 25-30 parts; grafted sodium polyacrylate polyurethane: 15-20 parts; Nano-montmorillonite modified cellulose: 5-8 parts; borate bond modified polysiloxane: 3-5 parts; polyethylene glycol thiol: 2-3 parts; Catalyst: 0.05-0.1 parts; Plasticizer: 3-5 parts; Defoaming agent: 0.1-0.3 parts; Antioxidant: 0.2-0.5 parts.
2. The polyurethane composite material for mining cables according to claim 1, characterized in that: The NCO content of the toluene diisocyanate is 6-8%.
3. The polyurethane composite material for mining cables according to claim 1, characterized in that: The catalyst is dibutyltin dilaurate.
4. The polyurethane composite material for mining cables according to claim 1, characterized in that: The plasticizer is polyethylene glycol.
5. The polyurethane composite material for mining cables according to claim 1, characterized in that: The defoaming agent is an organosilicon defoaming agent.
6. The polyurethane composite material for mining cables according to claim 1, characterized in that: The antioxidant is one or more of 1010 antioxidant or butylated hydroxytoluene.
7. A method for preparing the polyurethane composite material for mining cables according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) reacting polyoxypropylene glycol and toluene diisocyanate in the presence of a catalyst to prepare a polyurethane prepolymer; (2) mixing grafted sodium polyacrylate polyurethane with nano-montmorillonite modified cellulose to perform surface composite modification to obtain a modified functional filler; (3) the polyurethane prepolymer prepared in step (1), the modified functional filler prepared in step (2), the borate bond-modified polysiloxane and the polyethylene glycol thiol are put into a high-speed mixer for mixing, and then the remaining materials are added into a low-speed stirring tank for homogenization; (4) The mixed material is injected into a mold after vacuum degassing, and is formed through a step curing and post-curing process to obtain a polyurethane composite material.
8. The preparation method according to claim 7, characterized in that The reaction temperature in step (1) is 70-80° C., and the reaction time is 2-3 hours.
9. The preparation method according to claim 7 or 8, characterized in that The step curing process in step (4) is specifically as follows: first curing at 80°C for 1 to 3 hours, then heating to 120°C for curing for 1 to 2 hours; and the post-curing process is standing and curing in a 25°C environment for 12 to 36 hours.
10. A tensile and corrosion-resistant mining cable, characterized in that: include: Three wire cores are evenly distributed in a 120° circle, and each wire core is composed of a conductor (1) and an aramid fiber wrapped around the conductor from the inside to the outside. It consists of a fiber water-blocking layer (2), an inner insulating layer (3), an outer insulating layer (4) and a semi-conductive water-blocking layer (5); The outer sides of the three wire cores are sequentially coated with a filling layer (6), a wrapping layer (7), an armor layer (8) and an outer sheath layer (9); The filling layer (6) uses the polyurethane composite material for mining cables according to any one of claims 1 to 6.
Citation Information
Patent Citations
Synthesis method of composite polyurethane for cable
CN105384909A