Waterproof polyurethane material, preparation method and application of waterproof polyurethane material in flexible cable

Abstract

The invention discloses a waterproof polyurethane material, a preparation method and application of the waterproof polyurethane material in a flexible cable, and relates to the technical field of polymer cable materials. The polyurethane material comprises the following raw material components: polyurethane, a thermoplastic polyester elastomer, a compatilizer, an inorganic filler, a dynamic cross-linking agent and an organic tin catalyst, the dynamic cross-linking agent comprises lipoic acid and / or cystamine; the inorganic filler is composed of mica powder and zirconium oxide according to the mass ratio of (2-6): 1. According to the polyurethane material disclosed by the invention, a specific amount of the specific dynamic crosslinking agent is added, so that local failure caused by stress concentration can be avoided, the fatigue resistance and the water vapor permeation resistance are enhanced, and the environmental adaptability and durability of a seabed are improved.

Description

Technical Field

[0001] This invention relates to the field of polymer cable materials technology, and more specifically, to a waterproof polyurethane material and its preparation method, and its application in flexible cables. Background Technology

[0002] Underwater robot cables are key components connecting surface control systems and underwater equipment, responsible for transmitting power, signals, and data, while also withstanding the mechanical stress, water pressure, and corrosion of the complex marine environment. Their design and performance directly affect the robot's reliability, operating depth, and communication quality.

[0003] Currently, the main materials used for robot cables are polyvinyl chloride (PVC) and polyurethane (PU). Polyurethane (PU) possesses advantages such as high flexibility, high tensile strength, high fatigue stability, strong anti-interference performance, and good resistance to high and low temperatures, making it a promising material for underwater robot cables. However, polyurethane has poor water resistance, and its fatigue resistance significantly decreases when used in complex seabed environments with rock friction and mechanical impacts, making it prone to cracking or breakage.

[0004] Patent CN118580670A proposes a flexible cable material for robots and its preparation method. The plastic material is composed of polyurethane elastomer, EPDM rubber and TPEE. This flexible cable material has good mechanical properties, high temperature resistance and low temperature resistance, good fatigue stability after long-term use, and is not easy to deform or crack. However, this material is not suitable for underwater robot cables and cannot improve the defects of fatigue resistance and long-term reliability degradation when operating in complex seabed environments. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a polyurethane material for underwater robots that has excellent fatigue resistance and long-term reliability in complex seabed environments.

[0006] One of the objectives of this invention is to provide a method for preparing polyurethane materials for underwater robots.

[0007] One of the objectives of this invention is to provide a flexible cable made of the aforementioned polyurethane material.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A polyurethane material, the raw materials comprising the following components in parts by weight:

[0010] 100 parts of polyurethane

[0011] 50-60 parts of thermoplastic polyester elastomer,

[0012] 5-10 parts compatibilizer

[0013] 20-35 parts of inorganic filler

[0014] 8-16 parts of dynamic crosslinking agent

[0015] 0.1-2 parts of organotin catalyst;

[0016] The dynamic crosslinking agent includes lipoic acid and / or cystamine;

[0017] The inorganic filler is composed of mica powder and zirconium oxide in a mass ratio of (2-6):1, and the particle size of the inorganic filler satisfies the following: 25μm≤mica powder D95 particle size≤50μm, 0.5μm≤zirconia D95 particle size≤5μm.

[0018] The polyurethane material of this invention uses polyurethane (PU) as the matrix and is compounded with a specific amount of thermoplastic polyester elastomer (TPEE), giving the material good flexibility and fatigue resistance. Simultaneously, a specific amount of a dynamic crosslinking agent is added, enabling the grafting of disulfide dynamic crosslinking bonds onto the polyurethane chain segments. When the material is subjected to alternating stress from water flow impact, these dynamic crosslinking bonds break and absorb energy, reducing stress concentration and preventing macroscopic crack formation. Furthermore, the dynamic crosslinking bonds possess a certain degree of self-repairing and rebuilding properties, preventing the propagation of microcracks and resisting water vapor penetration, thereby improving the material's fatigue resistance and crack resistance. In addition, the inorganic filler of this invention uses layered mica powder and zirconium oxide with specific particle sizes, which combine with the dynamic crosslinking network through interfacial phase interaction, avoiding localized failure caused by stress concentration. This improves the tensile strength and shear strength of the cable, inhibits crack propagation, enhances fatigue resistance, strengthens water vapor penetration resistance, and improves environmental adaptability and durability.

[0019] Furthermore, the polyurethane is a polyether-type polyurethane and / or a polyester-type polyurethane.

[0020] Further, the thermoplastic polyester elastomer is a copolymer of a soft segment polyether glycol and a hard segment aliphatic polyester. Preferably, the soft segment polyether glycol is selected from polytetrahydrofuran monomer; preferably, the hard segment aliphatic polyester is selected from polybutylene terephthalate monomer.

[0021] Preferably, the thermoplastic polyester elastomer content that achieves the purpose of the invention can be any content within the range of 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts or more.

[0022] Furthermore, the dynamic crosslinking agent is lipoic acid and cystamine in a mass ratio of (2-5):1. Lipoic acid provides cyclic disulfide bonds to the material, while cystamine provides linear disulfide bonds. By using specific amounts of lipoic acid and cystamine in combination, a composite dynamic covalent crosslinking network can be constructed, reducing stress concentration and crack formation, and improving fatigue resistance.

[0023] Preferably, the content of the dynamic crosslinking agent that can achieve the purpose of the invention can be any content in the range of 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts or more.

[0024] Furthermore, the compatibilizer is POE-g-MAH and / or PS-g-MAH.

[0025] Furthermore, the mica powder and zirconium oxide are composed in a mass ratio of (3-5):1.

[0026] Preferably, the content of the inorganic filler that can achieve the purpose of the invention can be any content within the range of 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts or more.

[0027] Preferably, the particle size of the inorganic filler satisfies: 30μm≤mica powder D95 particle size≤40μm, 2μm≤zirconia D95 particle size≤4μm.

[0028] Furthermore, the organotin catalyst is dibutyltin dilaurate and / or stannous octoate.

[0029] Furthermore, it also includes: 0.1-2 parts antioxidant, 0.1-2 parts plasticizer, and 0.1-1 parts lubricant.

[0030] Preferably, the antioxidant is selected from hindered phenolic antioxidants, or a combination of hindered phenolic antioxidants and phosphites.

[0031] Preferably, the hindered phenolic antioxidant is selected from at least one of antioxidant 1010, antioxidant 1076 and antioxidant 2246.

[0032] Preferably, the hindered phenolic antioxidant is selected from antioxidant 168 and / or antioxidant 2103.

[0033] Preferably, the plasticizer is selected from at least one of dioctyl phthalate, polypropylene adipate, and epoxidized soybean oil.

[0034] Preferably, the lubricant is at least one selected from stearamide, zinc stearate, glyceryl monostearate, polyethylene wax, and polyethylene glycol.

[0035] This invention provides a flexible cable made of polyurethane material; specifically, the flexible cable is a cable material for underwater robots.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] The polyurethane material of this invention is a blend of polyurethane and thermoplastic polyester elastomer in specific proportions, giving the material good flexibility and fatigue resistance. Simultaneously, the addition of a specific dynamic crosslinking agent enables the formation of disulfide dynamic crosslinking bonds. When the material is subjected to alternating stress from water flow impact, these dynamic crosslinking bonds break and absorb energy, reducing stress concentration points. Furthermore, the dynamic crosslinking bonds can dynamically recombine and repair themselves, resulting in excellent fatigue resistance and crack resistance in complex seabed environments. Meanwhile, the inorganic filler, a combination of layered mica powder and zirconium oxide with specific particle sizes, combines with the dynamic crosslinking network through interfacial phase interaction, preventing localized failure caused by stress concentration, enhancing fatigue resistance and water vapor permeability resistance, and improving environmental adaptability and durability. Detailed Implementation

[0038] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0039] The reagents used in the various embodiments and comparative examples of this invention are as follows:

[0040] PU-1: Thermoplastic polyether polyurethane, Elastollan TPU 1180A, BASF (Germany).

[0041] PU-2: Thermoplastic polyether polyurethane, Elastollan TPU 1185A, BASF (Germany).

[0042] PU-NH: Amino ether polyurethane, NH 1520, Covestro, Germany.

[0043] TPEE-1: Hytrel 4056, DuPont, USA.

[0044] TPEE-2: Hytrel 4068, DuPont, USA.

[0045] Compatibilizer: POE-g-MAH, AMPLIFY GR216, Dow Chemical Company, USA.

[0046] Inorganic packing:

[0047] The inorganic filler raw materials were ground and sieved, and their D95 particle size was determined using a laser particle size analyzer. Among them, the mica powder was sourced from Lingshou County Huajing Mica Co., Ltd., G-8; the zirconium oxide was cubic zirconium oxide containing 8.5% yttrium oxide stabilizer, sourced from Saint-Gobain, France, YZ8.

[0048] Mica powder #1: D95 particle size is 15μm;

[0049] Mica powder #2: D95 particle size is 25μm;

[0050] Mica powder #3: D95 particle size is 35μm;

[0051] Mica powder #4: D95 particle size is 50μm;

[0052] Mica powder #5: D95 particle size is 70μm;

[0053] Zirconium oxide 1#: D95 particle size is 0.1μm;

[0054] Zirconia 2#: D95 particle size is 1μm;

[0055] Zirconia 3#: D95 particle size is 3μm;

[0056] Zirconia 4#: D95 particle size is 5μm;

[0057] Zirconia 5#: D95 has a particle size of 10μm.

[0058] Lipoic acid: Condis Chemical Company.

[0059] Cystamine: Cystamine dihydrochloride, Hubei Darli Chemical Co., Ltd.

[0060] Glutaraldehyde, Huayu Chemical Company.

[0061] Catalyst: Dibutyltin dilaurate.

[0062] Antioxidants: Antioxidant 1010 and Antioxidant 168 in a mass ratio of 1:1.

[0063] Plasticizer: Dioctyl phthalate (DOP).

[0064] Lubricant: stearamide.

[0065] Examples 1-19 and Comparative Examples 1-9

[0066] Examples 1-19 and Comparative Examples 1-9 provide different polyurethane materials, differing only in the types and amounts of each component. By weight, Examples 1-19 and Comparative Examples 1-9 include the components shown in Table 1-3.

[0067] The preparation method of the polyurethane material in the following examples and comparative examples includes the following steps: mixing each component evenly and heating to 150°C for 2 hours, then extruding and molding using a twin-screw extruder at 210±5°C, cooling and granulating to obtain the polyurethane material.

[0068] Table 1. Components (parts by weight) of Examples 1-9

[0069]

[0070] Table 2. Components (parts by weight) of Examples 10-19

[0071]

[0072]

[0073] Table 3. Components (parts by weight) of Comparative Examples 1-9

[0074]

[0075]

[0076] Performance testing

[0077] The following performance tests were performed on the polyurethane materials of each embodiment and comparative example:

[0078] 1. Tensile strength

[0079] Its tensile strength at room temperature was tested according to the test method of standard EN 50363-10-2 (2005).

[0080] 2. Long-term stability

[0081] Accelerated aging treatment was carried out for 192 hours according to the method of standard IEC 60811-507. The accelerated aging conditions were: irradiation by a xenon arc lamp (wavelength 290-800nm) with an irradiance of 0.51W / m². 2 The humidity was 50±5%RH; then the tensile strength after aging was tested.

[0082] 3. Bending fatigue test

[0083] Following the method of standard DNVGL-RP-F401 (2017), the sample was immersed in simulated seawater at 4±1℃ for 48 hours, and then subjected to cyclic bending test using a bending fatigue testing machine. The bending radius R = 10D and the cycle frequency was 0.5Hz. The number of cycles when the material cracked was recorded.

[0084] 4. Water vapor permeability

[0085] The test was conducted according to the method of standard E96 / E96M-24. The test conditions were: temperature 23℃, humidity 80%RH, and injection molded sample thickness 1.0±0.05mm.

[0086] The experimental results are shown in Table 4 below:

[0087] Table 4 Performance Test Results

[0088]

[0089]

[0090] As shown in Table 4, the polyurethane material of the present invention exhibits high tensile strength retention after aging, good long-term stability, excellent resistance to water vapor penetration, and a flexural fatigue resistance of up to 1.3 × 10⁻⁶. 6 More than once.

[0091] Compared to Example 1, Comparative Example 1, lacking a dynamic crosslinking agent, exhibited decreased aging resistance and flexural fatigue. Comparative Example 2, with its reversible Schiff base bonds, improved flexural fatigue to some extent, but its aging resistance was poor. Comparative Example 3, lacking TPEE compounding, showed decreased tensile strength and flexural fatigue. In Comparative Examples 4-9, when the content and particle size of inorganic fillers exceeded a certain range, their tensile strength, flexural fatigue, and water vapor permeability resistance decreased to varying degrees.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polyurethane material, characterized in that, The raw materials consist of the following components in parts by weight: The dynamic crosslinking agent includes lipoic acid and / or cystamine; The inorganic filler is composed of mica powder and zirconium oxide in a mass ratio of (2-6):1, and the particle size of the inorganic filler satisfies the following: 25μm≤mica powder D95 particle size≤50μm, 0.5μm≤zirconia D95 particle size≤5μm.

2. The polyurethane material as described in claim 1, characterized in that, The dynamic crosslinking agent is thioctic acid and cystamine in a mass ratio of (2-5):

1.

3. The polyurethane material as described in claim 1, characterized in that, The thermoplastic polyester elastomer is a copolymer of soft segment polyether glycol and hard segment aliphatic polyester.

4. The polyurethane material as described in claim 1, characterized in that, The compatibilizer is POE-g-MAH and / or PS-g-MAH.

5. The polyurethane material as described in claim 1, characterized in that, The mica powder and zirconium oxide are composed of a mass ratio of (3-5):

1.

6. The polyurethane material as described in claim 1, characterized in that, The organotin catalyst is dibutyltin dilaurate and / or stannous octoate.

7. The polyurethane material as described in claim 1, characterized in that, The polyurethane is a polyether-type polyurethane and / or a polyester-type polyurethane.

8. The polyurethane material as described in claim 1, characterized in that, Also includes: Antioxidant 0.1-2 parts, plasticizer 0.1-2 parts, lubricant 0.1-1 parts.

9. A method for preparing the polyurethane material according to any one of claims 1-8, characterized in that, include: The components are mixed evenly, melt-extruded and granulated to obtain the polyurethane material.

10. A flexible cable, characterized in that, Made using the polyurethane material described in any one of claims 1-8.

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