Corrosion-resistant rubber dam and preparation method thereof

Abstract

The invention relates to the technical field of hydraulic engineering materials, and particularly discloses a corrosion-resistant rubber dam and a preparation method thereof. The rubber dam is prepared by the following steps: forming a composite matrix (in a mass ratio of 60: 25: 15) by using ethylene propylene diene monomer (EPDM), brominated butyl rubber (BIIR) and hydrogenated butadiene-acrylonitrile rubber (HNBR), adding silane coupling agent modified nano zirconium oxide-aluminum oxide composite powder (ZrO2-Al2O3 with the particle size of 30-80nm) as a corrosion-resistant filler, and carrying out two-stage mixing and gradient vulcanization processes. The tensile strength retention rate of the obtained product in a corrosive environment with the pH value of 1-14 is larger than or equal to 92%, the ultraviolet aging resistance life reaches 30 years, the air tightness is improved by 5 times (the leakage rate is smaller than or equal to 2% / month) compared with a traditional EPDM dam, and the dam is suitable for high-corrosive water areas such as seawater backflow and acid rain.

Description

Technical Field

[0001] The present invention relates to a layered composite rubber dam, which is particularly suitable for an anti-seepage dam with an EPDM-BIIR-HNBR three-layer structure combined with a modified nylon canvas reinforcement layer, wherein nano ceramic powder (111) is dispersed near the surface of the BIIR layer (102). Background Art

[0002] A rubber dam, also known as a rubber sluice, is constructed with a high-strength synthetic fiber fabric as a load-bearing frame, coated internally and externally with rubber as a protective layer. This is then processed into a tape, anchored to a base plate to form a closed dam bag. This bag-type retaining dam is inflated with water (or air) through filling and discharge pipes. The dam top allows for overflow, and the dam height can be adjusted as needed to control upstream water levels, thereby maximizing benefits such as irrigation, power generation, shipping, flood control, and tide control.

[0003] Current rubber dam technology has the following core defects:

[0004] (1) Instability of anchoring structure

[0005] The essence of the problem: Traditional bolt anchoring relies on lateral locking force. Riverbed settlement causes the anchor groove to shift, causing the dam bag to slide sideways.

[0006] Consequences: Frequent manual calibration is required, and maintenance costs are significantly higher than those of rigid gates (steel dam lifespan 50 years vs. rubber dam lifespan 15-25 years).

[0007] (2) Bottleneck of dam bag material performance

[0008] Insufficient air tightness: EPDM rubber is inherently air permeable, with a standard permeability of 1.8×10 -8 cm 3 cm / cm 2 ·s·Pa (ISO 2782:2006); In actual projects, the dam height decays by ≥5% per week, and high-frequency inflation equipment is required.

[0009] Aging failure: Ultraviolet radiation causes EPDM molecular chains to break (GB / T 3511-2018 accelerated aging test: 1000-hour tensile strength retention rate ≤ 65%). Summary of the Invention

[0010] In view of the shortcomings of the existing technology, the present invention designs a corrosion-resistant rubber dam and a preparation method thereof, which is suitable for highly corrosive waters such as seawater backflow and acid rain.

[0011] To achieve the above object, the present invention provides the following technical solution: a corrosion-resistant rubber dam, comprising the following components in parts by weight:

[0012] 50-70 parts of ethylene propylene diene monomer (EPDM) with an ethylene content of 68%

[0013] 20-35 parts of brominated butyl rubber (BIIR)

[0014] 10-20 parts of hydrogenated nitrile rubber (HNBR, acrylonitrile content 34%)

[0015] 15-30 parts of nanocomposite ceramic powder (ZrO2-Al2O3, mass ratio 7:3, particle size 30-80nm)

[0016] Silane coupling agent KH-560 1.5~3.5 parts

[0017] Peroxide curing agent di-2,5 2.5~4.5 parts

[0018] Antioxidant 445 1~2.5 parts

[0019] 4-6 parts zinc oxide

[0020] Modified nylon canvas reinforcement layer (impregnated with epoxy resin, impregnation amount 25g / m 2 )

[0021] As an optional solution of the technical solution of the present invention, the nanocomposite ceramic powder is modified with a silane coupling agent by the following method: drying the powder at 120°C for 2 hours, ultrasonically dispersing it in an ethanol solution at a mass ratio of powder:KH-560=100:6 for 40 minutes, and curing it at 75°C for 2 hours.

[0022] As an optional solution of the technical solution of the present invention, the Mooney viscosity ML (1+4) of the brominated butyl rubber at 125° C. is 45±5, and the bromine content is 1.8 to 2.2 wt %.

[0023] As an optional solution of the technical solution of the present invention, it also includes 10 to 18 parts of reinforcing agent fumed silica and 6 to 10 parts of plasticizer cyclohexane oil.

[0024] A method for preparing a corrosion-resistant rubber dam comprises the following steps:

[0025] (1) Plasticizing: EPDM, BIIR, and HNBR were plasticized in an internal mixer at 65°C for 12 min;

[0026] (2) One-stage mixing: adding modified nano-ceramic powder, fumed silica, zinc oxide, and naphthenic oil, and mixing at 85°C for 10 min;

[0027] (3) Second stage mixing: add di-2,5 and antioxidant 445, mix at 55℃ for 4 minutes;

[0028] (4) Calendering compound: Calender the rubber compound to a thickness of 3-6 mm and cover both sides on the modified nylon canvas at a calendering temperature of 70°C;

[0029] (5) Gradient vulcanization: the first stage is 145℃×12min, pressure 18MPa; the second stage is 165℃×25min, pressure 22MPa.

[0030] As an optional solution of the technical solution of the present invention, the modified nylon canvas is treated with a composite impregnation solution of epoxy resin and carbon nanotubes (carbon nanotube content 3wt%), and the peel strength is ≥12kN / m.

[0031] As an optional solution of the technical solution of the present invention, after vulcanization, the joints of the dam body are coated with sealant, which is compounded by liquid brominated butyl rubber and graphene oxide in a ratio of 100:18, and has a thermal conductivity coefficient of ≥0.52W / (m·K).

[0032] As an optional solution of the technical solution of the present invention, after immersion in a 10% HSO solution for 30 days, the tensile strength retention rate is ≥94% (GB / T 1690).

[0033] As an optional solution of the technical solution of the present invention, after 1500 hours of ultraviolet accelerated aging, there is no crack on the surface and the elongation loss is ≤5% (ISO 4892-3).

[0034] As an optional solution of the technical solution of the present invention, the dam body adopts hot pressing seamless splicing technology, and the strength of the splicing reaches 98%±2% of the main body strength.

[0035] Beneficial effects of the present invention:

[0036] 1. Breakthrough improvement in air tightness: The gradient composite structure and nano-ceramic layer increase the gas permeability from the traditional EPDM cm 3 cm / cm 2 ·s·Pa reduced to ≤5.0×10 -9 cm 3 cm / cm 2 The dam's height reduction rate was optimized from ≥5% to ≤2%, the inflation frequency was reduced from once a week to once a month, and the energy consumption for operation and maintenance was reduced by 60%.

[0037] 2. Enhanced anchorage and settlement adaptability: The serrated hot-pressed anchoring system works in conjunction with a weighing base, ensuring anchorage force loss of ≤5% for a ±15cm riverbed displacement (compared to ≥30% for traditional anchoring). This system can achieve zero settlement maintenance for two consecutive years (compared to ≥3 annual maintenance visits for traditional anchoring systems), reducing lifecycle maintenance costs by 40% compared to steel gates.

[0038] 3. Low-temperature operational reliability: The air-water dual-control system, combined with the HNBR high-elastic layer (elastic modulus ≤ 5MPa at -40°C), enables normal operation at -25°C (the Mohe pilot project achieved a dam height error of ≤3% at -35°C extreme testing). Applicable areas have been expanded to cold temperate zones, increasing winter operating time by 60%.

[0039] 4. Doubled service life: A gradient vulcanization process (145°C x 12 minutes → 165°C x 8 minutes) and modified antioxidants ensure a strength retention rate of ≥ 90% after 1000 hours of UV-accelerated aging (GB / T 3511-2011, traditional EPDM ≤ 65%). The strength loss over 10 years of natural aging is ≤ 15%, extending the design life from 15 years to 30 years. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The present invention is a flow chart of the method for preparing the corrosion-resistant rubber dam. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] A corrosion-resistant rubber dam has a rectangular cross-section, an EPDM layer as a weather-resistant layer, a BIIR layer as an airtight layer, and an HNBR layer as an anti-hydrolysis layer; a canvas layer is longitudinally embedded between the layers, and has a tensile strength of ≥180 MPa. The total thickness of the dam is 12 mm, of which the EPDM outer layer is 3±0.2 mm thick, the BIIR middle layer is 5 mm thick, and the HNBR inner layer is 4 mm thick; the modified nylon canvas is embedded between the BIIR layer and the HNBR layer, and has a thickness of 0.8 mm. Nano-ceramic powder is densely distributed within the range of 0.05-0.1 mm on the upper surface of the BIIR layer (102), with a density gradient of 120 particles / μm. 2 →40 particles / μm 2 (0.2mm from the surface). The hot pressing joint is serrated, with a seam width of ≤0.2mm and an inclination of 45°.

[0043] A corrosion-resistant rubber dam, comprising the following components in parts by weight:

[0044] 50-70 parts of ethylene propylene diene monomer (EPDM) with an ethylene content of 68%

[0045] 20-35 parts of brominated butyl rubber (BIIR)

[0046] 10-20 parts of hydrogenated nitrile rubber (HNBR, acrylonitrile content 34%)

[0047] 15-30 parts of nanocomposite ceramic powder (ZrO2-Al2O3, mass ratio 7:3, particle size 30-80nm)

[0048] Silane coupling agent KH-560 1.5~3.5 parts

[0049] Peroxide curing agent di-2,5 2.5~4.5 parts

[0050] Antioxidant 445 1~2.5 parts

[0051] 4-6 parts zinc oxide

[0052] Modified nylon canvas reinforcement layer (impregnated with epoxy resin, impregnation amount 25g / m 2 )

[0053] Furthermore, the nanocomposite ceramic powder is modified with a silane coupling agent by drying the powder at 120° C. for 2 h, ultrasonically dispersing the powder in an ethanol solution at a mass ratio of powder:KH-560=100:6 for 40 min, and curing the powder at 75° C. for 2 h.

[0054] Furthermore, the Mooney viscosity ML (1+4) of the brominated butyl rubber at 125° C. is 45±5, and the bromine content is 1.8 to 2.2 wt %.

[0055] Furthermore, it also includes 10 to 18 parts of reinforcing agent fumed silica and 6 to 10 parts of plasticizer naphthenic oil.

[0056] like Figure 1 As shown, a method for preparing a corrosion-resistant rubber dam comprises the following steps:

[0057] (1) Plasticizing: EPDM, BIIR, and HNBR were plasticized in an internal mixer at 65°C for 12 min;

[0058] (2) One-stage mixing: adding modified nano-ceramic powder, fumed silica, zinc oxide, and naphthenic oil, and mixing at 85°C for 10 min;

[0059] (3) Second stage mixing: add di-2,5 and antioxidant 445, mix at 55℃ for 4 minutes;

[0060] (4) Calendering compound: Calender the rubber compound to a thickness of 3-6 mm and cover both sides on the modified nylon canvas at a calendering temperature of 70°C;

[0061] (5) Gradient vulcanization: the first stage is 145℃×12min, pressure 18MPa; the second stage is 165℃×25min, pressure 22MPa.

[0062] Furthermore, the modified nylon canvas is treated with a composite impregnation solution of epoxy resin and carbon nanotubes (the carbon nanotube content is 3 wt%), and the peel strength is ≥12 kN / m.

[0063] Furthermore, after vulcanization, the joints of the dam body are coated with a sealant, which is compounded by liquid brominated butyl rubber and graphene oxide in a ratio of 100:18, and has a thermal conductivity coefficient of ≥0.52W / (m·K).

[0064] Furthermore, after immersion in a 10% H2SO4 solution for 30 days, the tensile strength retention rate is ≥94% (GB / T 1690).

[0065] Furthermore, after 1500h of UV accelerated aging, there is no surface cracking and the elongation loss is ≤5% (ISO 4892-3).

[0066] Furthermore, the dam body adopts hot-pressed seamless splicing technology, and the strength of the splicing reaches 98%±2% of the body strength.

[0067] The present invention is further described below by way of examples. The examples are provided to illustrate the present invention in detail, but the present invention is not limited thereto. The animals, cells, drugs, and reagents used in the following examples are all commercially available products.

[0068] Example 1 (optimal ratio)

[0069] Raw materials: EPDM 60 parts, BIIR 25 parts, HNBR 15 parts, modified ZrO2-Al2O3 25 parts, KH-560 2.5 parts, bis-2,5 3.5 parts, antioxidant 445 2 parts, fumed silica 15 parts, and naphthenic oil 8 parts.

[0070] Process: The steps of claim 5 are performed, wherein the canvas impregnation liquid contains 3 wt% carbon nanotubes.

[0071] Performance testing:

[0072] Test items The present invention Comparative Example (CN44231647A) Test standards tensile strength 21.3MPa 16.8MPa GB / T 528 Resistant to 10% HCl (30 days) Strength retention rate 95% 85％ GB / T 1690 UV aging 1500h No cracks Crack length>3mm ISO 4892-3 Monthly leakage rate ≤2％ ≥15％ SL 227-2018 Canvas-rubber peel strength 13.6kN / m 8.2kN / m GB / T 532

[0073] Example 2 (low-cost solution):

[0074] Filler adjustment: nano ceramic powder is reduced to 18 parts, and modified clay is added to 12 parts;

[0075] Performance: tensile strength 19.1MPa, alkali resistance (10% NaOH) retention rate 90%, cost reduction 22%.

[0076] Comparative experiment:

[0077] Traditional CR dam: After immersion in 10% H2SO4 for 30 days, the strength decays to 68%;

[0078] Single EPDM dam: Surface powdering (weight loss rate > 5%) occurs after 800 hours of UV aging.

[0079] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

[0080] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A corrosion-resistant rubber dam, characterized in that: Calculated by weight, it includes the following components: 50-70 parts of ethylene propylene diene monomer (EPDM) with an ethylene content of 68% 20-35 parts of brominated butyl rubber (BIIR) 10-20 parts of hydrogenated nitrile rubber (HNBR, acrylonitrile content 34%) 15-30 parts of nanocomposite ceramic powder (ZrO2-Al2O3, mass ratio 7:3, particle size 30-80nm) 1.5-3.5 parts of silane coupling agent KH-560 Peroxide curing agent di-2,5 2.5~4.5 parts Antioxidant 445 1~2.5 parts 4-6 parts zinc oxide Modified nylon canvas reinforcement layer (impregnated with epoxy resin, impregnation amount 25g / m 2 ).

2. The corrosion-resistant rubber dam according to claim 1, characterized in that: The nanocomposite ceramic powder is modified with a silane coupling agent by drying the powder at 120° C. for 2 h, ultrasonically dispersing the powder in an ethanol solution at a mass ratio of powder to KH-560 of 100:6 for 40 min, and curing the powder at 75° C. for 2 h.

3. The corrosion-resistant rubber dam according to claim 1, characterized in that: The Mooney viscosity ML (1+4) of the brominated butyl rubber at 125° C. is 45±5, and the bromine content is 1.8-2.2 wt %.

4. The corrosion-resistant rubber dam according to claim 1, characterized in that: The invention also includes 10 to 18 parts of reinforcing agent fumed silica and 6 to 10 parts of plasticizer naphthenic oil.

5. A method for preparing a corrosion-resistant rubber dam according to claims 1-4, characterized in that: The following steps are involved: (1) Plasticizing: EPDM, BIIR, and HNBR were plasticized in an internal mixer at 65°C for 12 min; (2) One-stage mixing: adding modified nano-ceramic powder, fumed silica, zinc oxide, and naphthenic oil, and mixing at 85°C for 10 min; (3) Second stage mixing: add di-2,5 and antioxidant 445, mix at 55℃ for 4 minutes; (4) Calendering compound: Calender the rubber compound to a thickness of 3-6 mm and cover both sides on the modified nylon canvas at a calendering temperature of 70°C; (5) Gradient vulcanization: the first stage is 145℃×12min, pressure 18MPa; the second stage is 165℃×25min, pressure 22MPa.

6. The method for preparing the corrosion-resistant rubber dam according to claim 5, characterized in that: The modified nylon canvas is treated with a composite impregnation solution of epoxy resin and carbon nanotubes (the carbon nanotube content is 3 wt%), and has a peel strength of ≥12 kN / m.

7. The method for preparing the corrosion-resistant rubber dam according to claim 5, characterized in that: After vulcanization, the joints of the dam body are coated with sealant, which is a compound of liquid brominated butyl rubber and graphene oxide at a ratio of 100:18, and has a thermal conductivity of ≥0.52W / (m·K).

8. The corrosion-resistant rubber dam according to claim 1, characterized in that: After immersion in 10% H2SO4 solution for 30 days, the tensile strength retention rate is ≥94% (GB / T 1690).

9. The corrosion-resistant rubber dam according to claim 1, characterized in that: After 1500h of UV accelerated aging, there is no crack on the surface and the elongation loss is ≤5% (ISO 4892-3).

10. The corrosion-resistant rubber dam according to claim 1, characterized in that: The dam body adopts hot pressing seamless splicing technology, and the strength of the splicing reaches 98%±2% of the body strength.

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