Corrosion-resistant waterstop and method of making same

Abstract

The application discloses a kind of corrosion-resistant waterstop and preparation method thereof, relate to the technical field of waterstop of polymer compound composition.A kind of corrosion-resistant waterstop is composed of the following mass parts of raw materials: ethylene-propylene-diene rubber 50-70 parts, chloroprene rubber 20-40 parts, zinc oxide 3-8 parts, stearic acid 1-3 parts, antioxidant 1-2 parts, paraffin oil 5-15 parts, white carbon black 20-40 parts, calcium carbonate 30-50 parts, sulfur 1.5-3 parts, accelerator 0.5-1.5 parts.Accelerator precisely controls sulfur crosslinking process, forms high-density and uniform sulfur bond network structure, so that the material can still maintain excellent tensile strength, elongation at break and other mechanical properties in corrosive environment, to avoid sealing failure caused by swelling or aging.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polymer compound composition waterstop, in particular to a corrosion-resistant waterstop and a preparation method thereof. BACKGROUND

[0002] In the scenarios of building engineering expansion joints, tunnel joints, water conservancy engineering joints, and chemical plant joints, waterstops play a crucial role in waterproof sealing. However, existing waterstops still have many problems in practical application.

[0003] Traditional waterstops are mainly made of rubber materials such as natural rubber and nitrile rubber. These materials have certain elasticity and sealing properties, but their corrosion resistance is poor. In complex environmental conditions, such as long-term contact with groundwater, acid and alkali substances in the soil, and corrosive media in chemical plants, waterstops are prone to aging and corrosion. This can lead to a decline in their structural properties, causing cracks, deformation, and other problems, which can affect the waterproofing effect and cause leakage hazards.

[0004] In building engineering, if the expansion joint waterstop is corroded, it will not only cause the interior of the building to be damp and damaged, affecting the service life of the building, but also may cause serious structural safety problems. In tunnel engineering, corrosion of the waterstop can cause water seepage on the inner wall of the tunnel, affecting the normal use and safety of the tunnel. In water conservancy engineering, failure of the waterstop can lead to waste of water resources and damage to water conservancy facilities, and even cause floods and other disasters. In chemical plants, corrosion of the waterstop can cause leakage of chemicals, leading to environmental pollution and safety accidents, causing huge economic losses and social harm.

[0005] In addition, the existing waterstop preparation process has limitations in improving the corrosion resistance of the material. The treatment of raw materials in the preparation process is not fine enough, and the synergistic effect of the components cannot be fully utilized to improve the corrosion resistance. At the same time, the optimization of key process parameters such as vulcanization is insufficient, and the rubber molecules cannot be fully cross-linked to form a dense protective structure, so they cannot effectively resist the corrosion of corrosive substances.

[0006] In summary, the development of a waterstop with excellent corrosion resistance and a preparation method thereof has important practical significance for ensuring the safe and reliable operation of building engineering, tunnels, water conservancy engineering, and chemical plants. SUMMARY

[0007] The present application aims to solve the problem of insufficient corrosion resistance of existing waterstops by optimizing the material formula and preparation process, and provides a waterstop with excellent corrosion resistance in complex environments and a preparation method thereof to meet the waterproof sealing needs in the fields of building engineering, tunnels, water conservancy engineering, and chemical plants.

[0008] To achieve the above object, the technical scheme adopted by the present application is as follows: A kind of corrosion-resistant waterstop, which is composed of the following raw materials by mass fraction: ethylene-propylene-diene rubber 50-70 parts, chlorobutyl rubber 20-40 parts, zinc oxide 3-8 parts, stearic acid 1-3 parts, antioxidant 1-2 parts, paraffin oil 5-15 parts, white carbon black 20-40 parts, calcium carbonate 30-50 parts, sulfur 1.5-3 parts, accelerator 0.5-1.5 parts;

[0009] The accelerator is a structure shown in formula 1:

[0010] Formula 1;

[0011] The Z1 is selected from: O, S, C (CH3) (CH3), NH.

[0012] Further, the ethylene content of the ethylene-propylene-diene rubber is 50-60wt%, and the Mooney viscosity [ML (1+4) 125℃] is 50-70.

[0013] Further, the chlorobutyl rubber is CR122 type chlorobutyl rubber.

[0014] Further, the antioxidant is N-isopropyl-N , -phenyl-p-phenylenediamine and / or N- (1, 3-dimethylbutyl) -N , -phenyl-p-phenylenediamine.

[0015] Further, the structure of the N-isopropyl-N , -phenyl-p-phenylenediamine is: .

[0016] Further, the structure of the N- (1, 3-dimethylbutyl) -N , -phenyl-p-phenylenediamine is: .

[0017] Further, the accelerator is any one of the compounds shown in the following structures:

[0018] .

[0019] Further, the synthesis method of the accelerator is:

[0020] ;

[0021] First step: raw material 1 and raw material 2 are subjected to substitution reaction to synthesize intermediate 1;

[0022] Second step: intermediate 1 and raw material 3 are subjected to Buchwald-Hartwig aryl amination reaction to synthesize intermediate 2;

[0023] Step 3: The promoter is synthesized by Buchwald-Hartwig aryl amination reaction of intermediate 2 and raw material 4.

[0024] A preparation method of a corrosion-resistant waterstop, comprising the following steps:

[0025] S1. The EPDM rubber, chloroprene rubber, zinc oxide, stearic acid, antioxidant are added into a mixer, and mixed at 80-100 DEG C for 3-5 minutes to obtain material A;

[0026] S2. The paraffin oil, white carbon black and calcium carbonate are added into the material A, and mixed at 120-140 DEG C for 8-12 minutes to obtain material B;

[0027] S3. The material B is transferred into an open mill, and the sulfur and the promoter are added, and mixed at 40-60 DEG C for 3-5 times to obtain a mixed rubber;

[0028] S4. The mixed rubber is placed into a mold, and vulcanized at 160-180 DEG C and 10-20 MPa for 10-30 minutes in a vulcanizing machine, and heat-treated at 70-80 DEG C for 2-4 hours in an oven, and cooled to room temperature to obtain a corrosion-resistant waterstop.

[0029] Further, the mixing process of S1 and S2 is carried out under inert gas protection.

[0030] Further, the vulcanization temperature is 165-175 DEG C, and the vulcanization time is 15-25 minutes.

[0031] Further, the mixing times are 4 times, and the roller distance of the open mill is 0.5-1.0 mm.

[0032] The application of the corrosion-resistant waterstop in waterproof sealing of building engineering expansion joints, tunnel joints, water conservancy engineering joints or chemical facility joints.

[0033] The promoter in the application is used in rubber processing, and the sulfur is a vulcanizing agent, but the reaction rate is slow and the efficiency is low when the sulfur acts alone, and the promoter accelerates the crosslinking reaction of sulfur and rubber molecules. Through the action of the promoter, the rubber molecular chain can form a more dense and uniform crosslinking network in a shorter time and lower energy consumption. This structure is the basis for the rubber to have high strength, elasticity and medium corrosion resistance. The promoter in the application improves the crosslinking density and uniformity, so that the rubber forms a more dense protective barrier, thereby reducing the diffusion of corrosive medium to the inside of the material, delaying swelling and aging, and maintaining long-term sealing performance (especially in corrosive environments such as chemical facilities and water conservancy projects). The promoter optimizes the vulcanization efficiency, ensures the uniform dispersion of the antioxidant in the crosslinking network, maximizes the anti-aging effect, and further prolongs the service life of the waterstop in the corrosive environment.

[0034] The application builds a dual-phase corrosion protection barrier by synergizing polar and non-polar properties of ethylene-propylene-diene monomer rubber and chloroprene rubber: the ethylene-propylene-diene monomer rubber provides an inert matrix resistant to ozone / acid-base corrosion, and the chlorine-containing structure of CR122 chloroprene rubber endows oil and polar medium stability. On this matrix, a gradient filling network is formed by white carbon black and calcium carbonate - white carbon black enhances crosslinking density, and calcium carbonate fills micro voids, synergistically reducing the permeability of corrosion medium. In the core additive system, the dual active center of the accelerator precisely controls sulfur crosslinking, forming a high-density uniform sulfur bond network that physically blocks corrosion diffusion; at the same time, it synergizes with the anti-aging agent to ensure that the anti-aging components are uniformly dispersed in the crosslinked skeleton, and long-term inhibit oxidative degradation. In the preparation process, segmented mixing under inert atmosphere ensures uniform dispersion of components and avoids high-temperature oxidation; low-temperature thin passage and precise vulcanization optimize crosslinking kinetics, allowing rubber molecules to form a dense three-dimensional network; post-heat treatment eliminates internal stress, ultimately obtaining a corrosion-resistant sealing structure with high crosslinking density, low defect rate, and long-term anti-aging, significantly reducing swelling rate and extending service life.

[0035] Compared with the prior art, the application has the following beneficial effects:

[0036] 1. Significantly improve corrosion resistance: by optimizing the rubber matrix (synergizing ethylene-propylene-diene monomer rubber and chloroprene rubber) and the filler system (white carbon black / calcium carbonate gradient filling), a more dense anti-permeation barrier is formed, effectively resisting the corrosion of acid-base medium, oil, and chemical corrosive substances, extending the service life of the waterstop in a corrosive environment.

[0037] 2. Strengthen mechanical property stability: the new accelerator precisely controls the sulfur crosslinking process, forming a high-density and uniform sulfur bond network structure, allowing the material to maintain excellent mechanical properties such as tensile strength and elongation at break in a corrosive environment, avoiding sealing failure due to swelling or aging.

[0038] 3. Optimize process and performance synergy: the combination of segmented mixing (inert gas protection), low-temperature thin passage, and precise vulcanization process ensures uniform dispersion of components and formation of a low-defect crosslinked network; post-heat treatment further eliminates internal stress, making the material structure more stable and improving the reliability and durability of the waterstop. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The synthesis method of the accelerator 1 described in the application is as follows: 1 HNMR chart.

[0040] Figure 2 The synthesis method of the accelerator described in the application is as follows: DETAILED DESCRIPTION

[0041] The technical solutions of the present application will be clearly and completely described below with reference to the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present application.

[0042] Synthesis Example 1

[0043] Synthesis of Accelerator 1:

[0044]

[0045] First step: under nitrogen atmosphere, 20 g of raw material 1, 21.67 g of aluminum chloride and 150 g of toluene were sequentially added into the reaction system, after stirring and mixing uniformly, the system temperature was reduced to-20℃, and then 12.73 g of raw material 2 in 50 ml of toluene solution was added dropwise, the temperature was increased to room temperature, and the reaction was carried out for 6 h. After the reaction was completed, the pH of the system was adjusted to neutral with 0.1 mol / L hydrochloric acid aqueous solution, 200 g of water was added, stirred, and then allowed to stand, and the organic phase was separated, dried, and column chromatography was performed with petroleum ether and dichloromethane mixture as eluent to obtain 20.60 g of intermediate 1. MS [MS+1]: 339.

[0046] Second step: under nitrogen atmosphere, 20.60 g of intermediate 1, 20.81 g of raw material 3, 1.66 g of tris(dibenzylideneacetone)dipalladium, 16.74 g of potassium carbonate, 0.6 g of tri-tert-butylphosphine and 210 g of toluene were sequentially added into the reaction system, the temperature was increased to 120℃, and the reaction was carried out for 12 h under reflux. After the reaction was completed, the temperature was slightly reduced, diatomite was used for filtration to remove the salt and catalyst, and then the filtrate was cooled to room temperature, washed with water for three times, and the organic phase was retained, and then the water phase was extracted with ethyl acetate. After the organic phases were combined, anhydrous magnesium sulfate was used for drying, and then dried and column chromatography was performed on silica gel with petroleum ether and ethyl acetate mixture as eluent to obtain 21.18 g of intermediate 2. MS [MS+1]: 546.

[0047] Third step: under nitrogen atmosphere, 21.18 g of intermediate 2, 13.66 g of raw material 4, 1.07 g of tris(dibenzylideneacetone)dipalladium, 10.72 g of potassium carbonate, 0.4 g of tri-tert-butylphosphine and 220 g of toluene were sequentially added into the reaction system, the temperature was increased to 120℃, and the reaction was carried out for 12 h under reflux. After the reaction was completed, the temperature was slightly reduced, diatomite was used for filtration to remove the salt and catalyst, and then the filtrate was cooled to room temperature, washed with water for three times, and the organic phase was retained, and then the water phase was extracted with ethyl acetate. After the organic phases were combined, anhydrous magnesium sulfate was used for drying, and then dried and column chromatography was performed on silica gel with petroleum ether and ethyl acetate mixture as eluent to obtain 23.08 g of accelerator 1. ​

[0048] Final product structure identification:

[0049] MS [MS+1] of Promoter 1: 758;

[0050] MS [MS+1] of Promoter 1: 1 HNMR-deuterated chloroform- Figure 1 : δ 8.63-8.56 (m, 1H), 7.90 (m, 1H), 7.86-7.73 (m, 5H), 7.72-7.52 (m, 3H), 7.27-7.19 (m, 1H), 6.95 (dd, 1H), 6.77 (dd, 1H), 5.24 (dd, 1H), 5.15 (dd, 1H), 4.88 (m, 1H), 4.61 (t, 3H), 3.80 (d, 6H), 2.62 (m, 1H), 2.41 (m, 1H), 0.87 (s, 9), 0.10 (s, 6H).

[0051] Synthesis Examples 2-4

[0052] Synthesis Examples 2-4 were synthesized in turn, and the synthesis method of Synthesis Example 1 was referred to, and raw material 2 therein was replaced, and the rest was the same as Synthesis Example 1. The specific structure of raw material 2, the structures of Promoters 2-4, and MS [MS+1] data are shown in the following table.

[0053]

[0054] Example 1

[0055] Preparation of a corrosion-resistant waterstop

[0056] Raw material composition: ethylene propylene diene rubber: 60 parts (ethylene content 55wt%, Mooney viscosity [ML (1+4) 125℃] 60), chlorobutyl rubber: 30 parts (CR122 type), zinc oxide: 5 parts, stearic acid: 2 parts, antioxidant: 1.5 parts (N-(1,3-dimethylbutyl)-N , phenyl-p-phenylenediamine), paraffin oil: 10 parts, white carbon black: 30 parts, calcium carbonate: 40 parts, sulfur: 2 parts, promoter: 1 part (Promoter 1 prepared in Synthesis Example 1 is selected).

[0057] Preparation method

[0058] S1. Add ethylene propylene diene rubber, chlorobutyl rubber, zinc oxide, stearic acid, antioxidant into a Banbury mixer, and mix at 90℃ for 4 minutes under nitrogen protection to obtain material A.

[0059] S2. Add paraffin oil, white carbon black, calcium carbonate into material A, and mix at 130℃ for 10 minutes under nitrogen protection to obtain material B.

[0060] S3. Transfer material B to the mill (roller gap 0.8 mm), add sulfur and accelerator 1, and thin pass 4 times at 50 °C to obtain a rubber compound.

[0061] S4. Place the rubber compound in a mold, and vulcanize in a vulcanizing machine at 170 °C, 15 MPa for 20 minutes, and then heat treat in an oven at 75 °C for 3 hours, and cool to room temperature to obtain a corrosion-resistant waterstop.

[0062] Examples 2-4

[0063] A corrosion-resistant waterstop was prepared according to the preparation method of Example 1, wherein the accelerator therein was replaced by the accelerator prepared in Synthesis Example 2-Synthesis Example 4 in turn, and the rest was the same as Example 1.

[0064] Comparative Example 1

[0065] A corrosion-resistant waterstop was prepared according to the preparation method of Example 1, wherein the accelerator therein was replaced by Comparative Compound 1, and the rest was the same as Example 1.

[0066] Comparative Compound 1: .

[0067] Comparative Example 2

[0068] A corrosion-resistant waterstop was prepared according to the preparation method of Example 1, wherein the accelerator therein was not added, and the rest was the same as Example 1.

[0069] Performance test:

[0070] The waterstop (a corrosion-resistant waterstop prepared in the examples and comparative examples) was cut into dumbbell-shaped samples of equal size according to the method specified in GB / T 9865.1, and immersed in a 0.2 mol / L aqueous hydrochloric acid solution for 4 h. The tensile stress-strain performance of the waterstop was determined according to GBT 528-1998, and the dumbbell-shaped waterstop sample was uniformly placed on the upper and lower clamps of a constant-speed moving tensile testing machine, and stretched. The testing machine was started to detect. The higher the tensile strength, breaking tensile strength and breaking elongation, the better the corrosion resistance.

[0071]

[0072] The embodiment group using the specific accelerator of the application exhibits overall superior mechanical property retention ability in acid corrosion environment, and the tensile strength and elongation at break are both significantly higher than those of the traditional accelerator control group and the no accelerator group. The accelerators with different heteroatom structures have a slight gradient effect on performance, and the N / O-containing accelerator is slightly better than the S / C-containing variant, which confirms the structure-activity relationship between molecular design and corrosion resistance. What is particularly key is that the performance of the control group presents a cliff-like decline, especially the comparative example 2, which leads to serious deterioration of material structure due to insufficient vulcanization, fully verifying the necessity of efficient accelerator for building a dense crosslinked network. The overall trend proves that the synergistic effect of ternary ethylene-propylene rubber / chlorobutyl rubber matrix, gradient filler and new accelerator successfully realizes the strengthening of anti-permeation corrosion barrier, and fundamentally solves the technical defect that the existing waterstop is easy to fail in the corrosion medium.

[0073] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A corrosion resistant waterstop, characterized by, The application relates to a kind of corrosion-resistant waterstop belts, which are prepared from the following raw materials in parts by mass: 50-70 parts of ethylene-propylene-diene rubber, 20-40 parts of chloroprene rubber, 3-8 parts of zinc oxide, 1-3 parts of stearic acid, 1-2 parts of antioxidant, 5-15 parts of paraffin oil, 20-40 parts of white carbon black, 30-50 parts of calcium carbonate, 1.5-3 parts of sulfur, and 0.5-1.5 parts of accelerator. The accelerator is a compound represented by the following formula 1: Formula 1; Z1 is selected from O, S, C(CH3)2, and NH. The ethylene content of the ethylene-propylene-diene rubber is 50-60 wt%, and the Mooney viscosity ML (1+4) 125℃ is 50-70. The chloroprene rubber is CR122 type chloroprene rubber; the antioxidant is N- isopropyl-N , - phenyl-p-phenylenediamine and / or N-(1,3-dimethylbutyl)-N , - phenyl-p-phenylenediamine.

2. A corrosion resistant waterstop as claimed in claim 1, wherein The accelerator is any one of the compounds represented by the following structures: 。 3. A method of producing a corrosion-resistant waterstop according to any one of claims 1 to 2, characterized in that, The application also discloses a preparation method of the corrosion-resistant waterstop belt. S1. The ethylene-propylene-diene rubber, chloroprene rubber, zinc oxide, stearic acid, and antioxidant are added into a mixer, and mixed at 80-100℃ for 3-5 minutes to obtain material A. S2. The paraffin oil, white carbon black, and calcium carbonate are added into the material A, and mixed at 120-140℃ for 8-12 minutes to obtain material B. S3. The material B is transferred into an open mill, and the sulfur and accelerator are added, and mixed for 3-5 times at 40-60℃ to obtain a mixed rubber. S4. The mixed rubber is placed in a mold, and vulcanized in a vulcanizing machine at 160-180℃ and 10-20 MPa for 10-30 minutes, and then heated in an oven at 70-80℃ for 2-4 hours, and then cooled to room temperature to obtain the corrosion-resistant waterstop belt.

4. The method of claim 3, wherein the corrosion-resistant waterstop is prepared by the steps of: The mixing process of S1 and S2 is carried out under the protection of inert gas.

5. The method for preparing a corrosion-resistant waterstop according to claim 3, characterized in that, The vulcanization temperature is 165-175℃, and the vulcanization time is 15-25 minutes.

6. The method of claim 3, wherein the corrosion-resistant waterstop is prepared by the steps of: The mixing times are 4 times, and the roller distance of the open mill is 0.5-1.0 mm.

7. The corrosion-resistant waterstop belt according to any one of claims 1-2 is used in the waterproof sealing of building engineering expansion joints, tunnel joints, water conservancy engineering joints, or chemical facility joints.

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