Rubber waterstop suitable for low-temperature environment of tunnel in cold region and preparation method of rubber waterstop

Abstract

The invention relates to the technical field of rubber waterstops, and discloses a rubber waterstop suitable for a low-temperature environment of a tunnel in a cold region and a preparation method of the rubber waterstop. The rubber waterstop suitable for the low-temperature environment of the tunnel in the cold region is prepared from the following raw materials in parts by mass: 100 to 150 parts of ethylene propylene diene monomer, 5 to 15 parts of homopolymerized epichlorohydrin rubber, 20 to 40 parts of acrylate rubber, 1 to 3 parts of liquid nitrile rubber, 0.01 to 0.1 part of phthalic anhydride, 5 to 10 parts of nano graphene oxide, 1 to 3 parts of tetraethoxysilane, 1 to 2 parts of amino silane and 40 to 60 parts of reinforcing agent. 1-3 parts of an anti-aging agent, 1-5 parts of a plasticizer, 1-2 parts of a vulcanizing agent and 1-2 parts of an accelerant. The obtained water stop belt is excellent in mechanical performance, tensile strength, tearing strength and compression set at the low temperature of-40 DEG C are excellent, cracking is avoided at the low temperature, and the water stop belt can better adapt to the extreme environment.

Description

Technical Field

[0001] The invention relates to the technical field of rubber waterstops, and in particular to a rubber waterstop suitable for low-temperature environments of tunnels in cold regions and a preparation method thereof. Background Art

[0002] With the construction of infrastructure, construction joints, settlement joints, and deformation joints are required due to deformation of the foundation and temperature changes. Rubber waterstops must be used at these joints to prevent leakage. Rubber waterstop materials use the high elasticity and compression deformation of rubber to produce elastic deformation under load, thereby effectively tightening and sealing. The elasticity of the rubber waterstop itself is used to compensate for the changes in the gaps at the structural joints, thereby achieving waterproof and anti-seepage effects. With the increasingly diversified development of industry, especially the increasingly complex working environment, more requirements are put forward for the use of waterstops.

[0003] The cold resistance of rubber refers to its ability to maintain elasticity and work normally under a specified low temperature environment. Under low temperature environment, the relaxation process of vulcanized rubber slows down sharply, the hardness, modulus and intramolecular friction increase, and the elasticity decreases significantly, resulting in a decrease in the working ability of rubber products, especially under dynamic conditions. In order to make rubber have good cold resistance, the coagulation energy between its molecules must be relatively small, the melting entropy must be large, that is, the movement between molecules must be relatively easy, and the crystallinity must be low.

[0004] The rubber industry uses a large amount of nanomaterials as fillers, and the amount of fillers used is second only to the amount of rubber consumed. The effect of fillers on the cold resistance of rubber depends on the structure formed after the interaction between the filler and the rubber. Different physical adsorption and strong chemical adsorption bonds will be formed between the activated carbon black particles and the rubber molecules, and an interface layer of raw rubber will be formed on the surface of the carbon black particles. The addition of fillers will hinder the change of the chain segment configuration. When this type of rubber is placed in a low temperature state, its molecular motion will be constrained, showing a higher molecular modulus, so its low temperature resistance effect will be weakened.

[0005] Nanomaterials refer to new materials with specific properties made by regulating the structure of matter at the nanoscale. At present, the development of the rubber industry is closely related to the use of nanomaterials. The operating conditions of waterstops are complex and changeable. The operating environment temperature of waterstops in cold areas is low, which leads to the deterioration of the elasticity and mechanical properties of rubber waterstops. If nanomaterials are used to regulate the rubber structure, a waterstop with good low-temperature resistance, high elasticity and excellent mechanical properties can be obtained, which will have great practical significance. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a rubber waterstop suitable for low-temperature environments of cold-region tunnels and a preparation method thereof.

[0007] A rubber waterstop suitable for low-temperature environments of tunnels in cold regions, wherein the raw materials thereof include, by mass, 100-150 parts of EPDM rubber, 5-15 parts of homopolymer epichlorohydrin rubber, 20-40 parts of acrylate rubber, 1-3 parts of liquid nitrile rubber, 0.01-0.1 parts of phthalic anhydride, 5-10 parts of nano-graphene oxide, 1-3 parts of tetraethyl orthosilicate, 1-2 parts of aminosilane, 40-60 parts of reinforcing agent, 1-3 parts of antioxidant, 1-5 parts of plasticizer, 1-2 parts of vulcanizer and 1-2 parts of accelerator.

[0008] Preferably, the aminosilane is γ-aminopropyltriethoxysilane.

[0009] Preferably, the liquid nitrile rubber is a carboxyl-terminated liquid nitrile rubber.

[0010] Preferably, the reinforcing agent is carbon black N550.

[0011] Preferably, the antioxidant is at least one of antioxidant AW, antioxidant D, antioxidant CPPD, and antioxidant IPPD.

[0012] Preferably, the plasticizer is at least one of dioctyl sebacate, dioctyl phthalate, dioctyl adipate, trioctyl phosphate and dibutyl phthalate.

[0013] Preferably, the vulcanizing agent is sulfur.

[0014] Preferably, the accelerator is at least one of zinc dibutyl dithiocarbamate and tetramethylthiuram disulfide.

[0015] The method for preparing the rubber waterstop suitable for low-temperature environments in cold-region tunnels comprises the following steps:

[0016] S1. Add nano-graphene oxide to ethanol aqueous solution and stir for 10-30 min, add tetraethyl orthosilicate and aminosilane thereto under stirring, stir at 80-90° C. for 1-2 h, filter, wash, and vacuum dry to obtain pretreated graphene;

[0017] S2, adding liquid nitrile rubber to an organic solvent and stirring evenly, adding pretreated graphene and phthalic anhydride thereto, stirring at 140-150° C. for 2-4 hours, filtering, vacuum drying, adding ethylene propylene diene rubber, homopolymer chloroether rubber, and acrylate rubber, and mixing at 140-160° C. for 1-3 minutes to obtain a premix;

[0018] S3. Add reinforcing agent, antioxidant and plasticizer to the premix and mix for 1-2 minutes. Thin it 2-6 times, cool it to 50-60℃, add vulcanizer and accelerator and mix evenly. Extrusion molding and vulcanization at 200-220℃.

[0019] Preferably, in S2, the organic solvent is N,N-dimethylformamide.

[0020] Beneficial effects:

[0021] 1. EPDM rubber has the advantages of good ozone resistance, heat resistance and weather resistance, but the low temperature performance of EPDM rubber cannot meet the performance requirements of the low temperature environment water stop of cold tunnels. It quickly fails when used in a -30°C environment and cannot be used. The present invention uses EPDM rubber, homopolymerized epichlorohydrin rubber and acrylate rubber as the base material, which can effectively reduce the glass transition temperature of the mixed rubber and improve the cold resistance of the rubber material.

[0022] 2. The present invention selects EPDM rubber, homopolymer epichlorohydrin rubber and acrylate rubber from raw rubber varieties, uses sulfur as a vulcanizing agent, and cooperates with an accelerator to form polysulfide bonds with less firmness and longer length, thereby further improving the cold resistance of the rubber.

[0023] 3. After the siloxane molecular structure is combined with the surface of nano-graphene oxide, the present invention is coated with nitrile rubber, and the graphene sheet structure is pre-crosslinked to form a macromolecular entanglement structure. A large number of active hydroxyl and carboxyl groups on it are further mixed with EPDM rubber, homopolymer chloroether rubber, and acrylate rubber, thereby entering the molecular chain structure, which not only achieves nano-scale dispersion, but also plays a plasticizing role in the processing process and participates in the reaction. On the one hand, while ensuring elasticity, it has excellent low-temperature resistance. On the other hand, it can fully promote uniform mixing of the system, which can be beneficial to the subsequent vulcanization of the waterstop.

[0024] If the present invention does not add aminosilane, and combines a silicon dioxide nanolayer structure on the nanographene oxide sheet and then combines it with liquid nitrile rubber, although the interface bonding effect between the nanographene oxide and the substrate can be improved, its cold resistance cannot meet the requirements, its elasticity is significantly reduced at a low temperature of -40°C, and its compression deformation resistance and tear resistance are extremely poor.

[0025] The present invention polycondenses tetraethyl orthosilicate and aminosilane and combines them on graphene oxide sheets, and then combines them with liquid nitrile rubber, which not only ensures a large interface phase size between the substrate and the interface phase size and interface strength in the substrate are extremely high, and elastic energy is stored, but also solidifies with the substrate, which is conducive to giving full play to the reinforcing and toughening effects of nano graphene oxide, and has excellent mechanical properties, especially little elasticity reduction at -40°C, and good low-temperature resistance.

[0026] 4. The pretreated graphene obtained in the present invention and the reinforcing agent can complement each other in the substrate and be used as an auxiliary reinforcing agent, which can significantly improve the compression deformation resistance, tear resistance and tensile strength of the product. At the same time, the process is simple, the processing performance is good, and the cost is low.

[0027] The waterstop obtained by the present invention has excellent mechanical properties, excellent tensile strength, tear strength and compression permanent deformation at a low temperature of -40°C, does not crack at low temperatures, and can better adapt to extreme environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a comparison chart of the hardness and compression permanent deformation of the rubber waterstop obtained in Example 5 and Comparative Examples 1-2 at room temperature and low temperature (-40°C).

[0029] Figure 2 This is a comparison chart of the tensile strength and tear strength of the rubber waterstop obtained in Example 5 and Comparative Examples 1-2 at room temperature and low temperature (-40°C).

[0030] Figure 3 This is a comparison chart of the brittle temperatures of the rubber waterstops obtained in Example 5 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0031] Example 1

[0032] A rubber waterstop suitable for low-temperature environments of tunnels in cold regions, wherein the raw materials include: 100 kg of EPDM rubber, 5 kg of homopolymer epichlorohydrin rubber, 20 kg of acrylate rubber, 1 kg of carboxyl-terminated liquid nitrile rubber, 0.01 kg of phthalic anhydride, 5 kg of nanographene oxide, 1 kg of tetraethyl orthosilicate, 1 kg of γ-aminopropyltriethoxysilane, 40 kg of carbon black N550, 1 kg of antioxidant AW, 1 kg of dioctyl sebacate, 1 kg of sulfur, and 1 kg of zinc dibutyl dithiocarbamate.

[0033] The method for preparing the rubber waterstop suitable for low-temperature environments in cold-region tunnels is characterized by comprising the following steps:

[0034] S1. Add nano-graphene oxide to 50 kg of 50% ethanol aqueous solution, stir at a speed of 1000 r / min for 10 min, add ethyl orthosilicate and γ-aminopropyltriethoxysilane thereto under stirring, stir at a temperature of 80° C. for 1 h, filter, wash once with ethanol, and vacuum dry to obtain pretreated graphene;

[0035] S2, add the carboxyl-terminated liquid nitrile rubber to 30 kg of toluene and stir evenly, add pretreated graphene and phthalic anhydride thereto, stir at a temperature of 140 ° C for 2 hours, filter, vacuum dry, add ethylene propylene diene rubber, homopolymer chloroether rubber, and acrylate rubber to an internal mixer, mix at a temperature of 140 ° C for 1 minute to obtain a premix;

[0036] S3. Add carbon black N550, antioxidant AW and dioctyl sebacate to the premix and mix for 1 minute. Send it to an open mixer and thin it twice. Cool it to 50°C. Add vulcanizing agent and zinc dibutyl dithiocarbamate and mix evenly. Send it to an extruder for extrusion molding. Send it to a vulcanizer for vulcanization at a vulcanization temperature of 200°C.

[0037] Example 2

[0038] A rubber waterstop suitable for low-temperature environments of tunnels in cold regions, the raw materials of which include: 150kg of EPDM rubber, 15kg of homopolymer epichlorohydrin rubber, 40kg of acrylate rubber, 3kg of carboxyl-terminated liquid nitrile rubber, 0.1kg of phthalic anhydride, 10kg of nano-graphene oxide, 3kg of tetraethyl orthosilicate, 2kg of γ-aminopropyltriethoxysilane, 60kg of carbon black N550, 3kg of antioxidant CPPD, 5kg of dioctyl adipate, 2kg of sulfur, and 2kg of zinc dibutyl dithiocarbamate.

[0039] The method for preparing the rubber waterstop suitable for low-temperature environments in cold-region tunnels is characterized by comprising the following steps:

[0040] S1. Add nano-graphene oxide to 100 kg of 70% ethanol aqueous solution, stir at a speed of 2000 r / min for 30 min, add ethyl orthosilicate and γ-aminopropyltriethoxysilane thereto under stirring, stir at a temperature of 90° C. for 2 h, filter, wash with ethanol 3 times, and vacuum dry to obtain pretreated graphene;

[0041] S2, add the carboxyl-terminated liquid nitrile rubber to 60 kg of xylene and stir evenly, add pretreated graphene and phthalic anhydride thereto, stir at a temperature of 150 ° C for 4 hours, filter, vacuum dry, add ethylene propylene diene rubber, homopolymer chloroether rubber, and acrylate rubber to an internal mixer, mix at a temperature of 160 ° C for 3 minutes to obtain a premix;

[0042] S3. Add carbon black N550, antioxidant CPPD and dioctyl adipate to the premix and mix for 2 minutes. Send it to an open mixer and pass it through for 6 times. Cool it to 60°C. Add vulcanizing agent and zinc dibutyl dithiocarbamate and mix evenly. Send it to an extruder for extrusion molding. Send it to a vulcanizer for vulcanization at a vulcanization temperature of 220°C.

[0043] Example 3

[0044] A rubber waterstop suitable for low-temperature environments of tunnels in cold regions, the raw materials of which include: 110kg of EPDM rubber, 12kg of homopolymer epichlorohydrin rubber, 25kg of acrylate rubber, 2.5kg of carboxyl-terminated liquid nitrile rubber, 0.03kg of phthalic anhydride, 9kg of nano-graphene oxide, 1.5kg of tetraethyl orthosilicate, 1.7kg of γ-aminopropyltriethoxysilane, 45kg of carbon black N550, 2.5kg of antioxidant IPPD, 2kg of dibutyl phthalate, 1.8kg of sulfur, and 1.4kg of tetramethylthiuram disulfide.

[0045] The method for preparing the rubber waterstop suitable for low-temperature environments in cold-region tunnels is characterized by comprising the following steps:

[0046] S1. Add nano-graphene oxide to 90 kg of 55% ethanol aqueous solution, stir at a speed of 1800 r / min for 15 min, add ethyl orthosilicate and γ-aminopropyltriethoxysilane thereto under stirring, stir at a temperature of 88° C. for 80 min, filter, wash twice with ethanol, and vacuum dry to obtain pretreated graphene;

[0047] S2, add the carboxyl-terminated liquid nitrile rubber to 50 kg of N, N-dimethylformamide and stir evenly, add pretreated graphene and phthalic anhydride thereto, stir at a temperature of 142 ° C for 3.5 hours, filter, vacuum dry, add ethylene propylene diene rubber, homopolymer chloroether rubber, and acrylate rubber to an internal mixer, mix at a temperature of 145 ° C for 2.5 minutes to obtain a premix;

[0048] S3. Add carbon black N550, antioxidant IPPD and dibutyl phthalate to the premix and mix for 1.5 minutes. Send it to an open mixer and pass it through for 3 times. Cool it to 58°C. Add vulcanizing agent and tetramethylthiuram disulfide and mix evenly. Send it to an extruder for extrusion molding. Send it to a vulcanizer for vulcanization at a vulcanization temperature of 205°C.

[0049] Example 4

[0050] A rubber waterstop suitable for low-temperature environments of tunnels in cold regions, the raw materials of which include: 130kg of EPDM rubber, 8kg of homopolymer epichlorohydrin rubber, 35kg of acrylate rubber, 1.5kg of carboxyl-terminated liquid nitrile rubber, 0.07kg of phthalic anhydride, 7kg of nano-graphene oxide, 2.5kg of tetraethyl orthosilicate, 1.3kg of γ-aminopropyltriethoxysilane, 55kg of carbon black N550, 1.5kg of antioxidant D, 4kg of dioctyl phthalate, 1.4kg of sulfur, and 1.8kg of tetramethylthiuram disulfide.

[0051] The method for preparing the rubber waterstop suitable for low-temperature environments in cold-region tunnels is characterized by comprising the following steps:

[0052] S1. Add nano-graphene oxide to 70 kg of 65% ethanol aqueous solution, stir at a speed of 1200 r / min for 25 min, add ethyl orthosilicate and γ-aminopropyltriethoxysilane thereto under stirring, stir at a temperature of 82° C. for 100 min, filter, wash twice with ethanol, and vacuum dry to obtain pretreated graphene;

[0053] S2, add the carboxyl-terminated liquid nitrile rubber to 40 kg of N, N-dimethylformamide and stir evenly, add pretreated graphene and phthalic anhydride thereto, stir at a temperature of 148 ° C for 2.5 hours, filter, vacuum dry, add ethylene propylene diene rubber, homopolymer chloroether rubber, and acrylate rubber to an internal mixer, mix at a temperature of 155 ° C for 1.5 minutes to obtain a premix;

[0054] S3. Add carbon black N550, antioxidant D and dioctyl phthalate to the premix and mix for 1.5 minutes. Send it to an open mixer and pass it through for 5 times. Cool it to 52°C. Add vulcanizing agent and tetramethylthiuram disulfide and mix evenly. Send it to an extruder for extrusion molding. Send it to a vulcanizer for vulcanization at a vulcanization temperature of 215°C.

[0055] Example 5

[0056] A rubber waterstop suitable for low-temperature environments of tunnels in cold regions, the raw materials of which include: 120kg of EPDM rubber, 10kg of homopolymer epichlorohydrin rubber, 30kg of acrylate rubber, 2kg of carboxyl-terminated liquid nitrile rubber, 0.05kg of phthalic anhydride, 8kg of nano-graphene oxide, 2kg of tetraethyl orthosilicate, 1.5kg of γ-aminopropyltriethoxysilane, 50kg of carbon black N550, 2kg of antioxidant CPPD, 3kg of trioctyl phosphate, 1.6kg of sulfur, and 1.6kg of tetramethylthiuram disulfide.

[0057] The method for preparing the rubber waterstop suitable for low-temperature environments in cold-region tunnels is characterized by comprising the following steps:

[0058] S1. Add nano-graphene oxide to 80 kg of 60% ethanol aqueous solution, stir at a speed of 1500 r / min for 20 min, add ethyl orthosilicate and γ-aminopropyltriethoxysilane thereto under stirring, stir at a temperature of 85° C. for 90 min, filter, wash twice with ethanol, and vacuum dry to obtain pretreated graphene;

[0059] S2, add the carboxyl-terminated liquid nitrile rubber to 45 kg of N, N-dimethylformamide and stir evenly, add pretreated graphene and phthalic anhydride thereto, stir at a temperature of 145 ° C for 3 hours, filter, vacuum dry, add ethylene propylene diene rubber, homopolymer chloroether rubber, and acrylate rubber to an internal mixer, mix at a temperature of 150 ° C for 2 minutes to obtain a premix;

[0060] S3. Add carbon black N550, antioxidant CPPD and trioctyl phosphate to the premix and mix for 1.5 minutes. Send it to an open mixer and pass it through for 4 times. Cool it to 55°C. Add vulcanizing agent and tetramethylthiuram disulfide and mix evenly. Send it to an extruder for extrusion molding. Send it to a vulcanizer for vulcanization at a vulcanization temperature of 210°C.

[0061] Comparative Example 1

[0062] A rubber waterstop suitable for low-temperature environments in cold-region tunnels, the raw materials of which include: 120kg of EPDM rubber, 10kg of homopolymer epichlorohydrin rubber, 30kg of acrylate rubber, 2kg of carboxyl-terminated liquid nitrile rubber, 0.05kg of phthalic anhydride, 8kg of nano-graphene oxide, 2kg of tetraethyl orthosilicate, 50kg of carbon black N550, 2kg of antioxidant CPPD, 3kg of trioctyl phosphate, 1.6kg of sulfur, and 1.6kg of tetramethylthiuram disulfide.

[0063] The method for preparing the rubber waterstop suitable for low-temperature environments in cold-region tunnels is characterized by comprising the following steps:

[0064] S1. Add nano-graphene oxide to 80 kg of 60% ethanol aqueous solution, stir at a speed of 1500 r / min for 20 min, add ethyl orthosilicate thereto under stirring, stir at a temperature of 85° C. for 90 min, filter, wash twice with ethanol, and vacuum dry to obtain pretreated graphene;

[0065] S2, add the carboxyl-terminated liquid nitrile rubber to 45 kg of N, N-dimethylformamide and stir evenly, add pretreated graphene and phthalic anhydride thereto, stir at a temperature of 145 ° C for 3 hours, filter, vacuum dry, add ethylene propylene diene rubber, homopolymer chloroether rubber, and acrylate rubber to an internal mixer, mix at a temperature of 150 ° C for 2 minutes to obtain a premix;

[0066] S3. Add carbon black N550, antioxidant CPPD and trioctyl phosphate to the premix and mix for 1.5 minutes. Send it to an open mixer and pass it through for 4 times. Cool it to 55°C. Add vulcanizing agent and tetramethylthiuram disulfide and mix evenly. Send it to an extruder for extrusion molding. Send it to a vulcanizer for vulcanization at a vulcanization temperature of 210°C.

[0067] Comparative Example 2

[0068] A rubber waterstop suitable for low-temperature environments of tunnels in cold regions, the raw materials of which include: 120kg of EPDM rubber, 10kg of homopolymer epichlorohydrin rubber, 30kg of acrylate rubber, 2kg of carboxyl-terminated liquid nitrile rubber, 0.05kg of phthalic anhydride, 8kg of nano-graphene oxide, 2kg of tetraethyl orthosilicate, 1.5kg of γ-aminopropyltriethoxysilane, 50kg of carbon black N550, 2kg of antioxidant CPPD, 3kg of trioctyl phosphate, 1.6kg of sulfur, and 1.6kg of tetramethylthiuram disulfide.

[0069] The method for preparing the rubber waterstop suitable for low-temperature environments in cold-region tunnels is characterized by comprising the following steps:

[0070] S1. Add nano-graphene oxide to 80 kg of 60% ethanol aqueous solution, stir at a speed of 1500 r / min for 20 min, add ethyl orthosilicate and γ-aminopropyltriethoxysilane thereto under stirring, stir at a temperature of 85° C. for 90 min, filter, wash twice with ethanol, and vacuum dry to obtain pretreated graphene;

[0071] S2, adding the carboxyl-terminated liquid nitrile rubber, pretreated graphene, phthalic anhydride, ethylene propylene diene rubber, homopolymer epichlorohydrin rubber, and acrylate rubber into an internal mixer, and mixing at a temperature of 150° C. for 2 minutes to obtain a premix;

[0072] S3. Add carbon black N550, antioxidant CPPD and trioctyl phosphate to the premix and mix for 1.5 minutes. Send it to an open mixer and pass it through for 4 times. Cool it to 55°C. Add vulcanizing agent and tetramethylthiuram disulfide and mix evenly. Send it to an extruder for extrusion molding. Send it to a vulcanizer for vulcanization at a vulcanization temperature of 210°C.

[0073] With reference to GB / T 18173.2-2014 "Polymer Waterproof Materials Part 2: Waterstop", the mechanical properties of the rubber waterstops obtained in Example 5 and Comparative Examples 1-2 at room temperature and low temperature (-40°C) were measured.

[0074] like Figure 1 As shown, the hardness of each group at room temperature is similar, lacking significant differences (P>0.05), while the rubber waterstop obtained in Example 5 has the lowest hardness in a -40°C environment, still at 55-65 Shore A, which is better than Comparative Examples 1-2 (P<0.05). At the same time, the compression permanent deformation of the rubber waterstop obtained in Example 5 is the lowest in a room temperature or low temperature environment, which is better than Comparative Examples 1-2 (P<0.05). Both indicate that the rubber waterstop obtained in Example 5 can still maintain flexibility in a low temperature environment and avoid failure.

[0075] like Figure 2 and Figure 3 As shown, the tensile strength and tear strength of the rubber waterstop obtained in Example 5 are the highest at room temperature or low temperature, while the brittle temperature is the lowest, both of which are better than those of Comparative Examples 1-2 (P < 0.05).

[0076] The applicant believes that this is because the present invention uses EPDM rubber, homopolymer epichlorohydrin rubber and acrylate rubber as the base material, which can not only effectively reduce the glass transition temperature of the mixed rubber and improve the cold resistance of the rubber material; but also uses sulfur as a vulcanizing agent, combined with the action of an accelerator, to form polysulfide bonds with less firmness and longer length, thereby improving the cold resistance of the rubber. At the same time, after the present invention combines the siloxane molecular structure on the surface of nano-graphene oxide, it is coated with acrylonitrile rubber, and the graphene sheet structure is pre-crosslinked to form a macromolecular entanglement structure, on which a large number of active hydroxyl groups and carboxyl groups are formed, which not only ensures a large interface phase size between the substrate, but also has extremely high interface phase size and interface strength in the substrate, stores elastic energy, and solidifies between the substrate, which is conducive to giving full play to the reinforcement and toughening effect of nano-graphene oxide, and has excellent mechanical properties, especially small elasticity reduction at -40°C, and good low-temperature resistance; further mixed with EPDM rubber, homopolymer chloroether rubber, and acrylate rubber, so as to enter the molecular chain structure, not only achieve nano-scale dispersion, but also play a plasticizing role in the processing process, and participate in the reaction, on the one hand, on the basis of ensuring elasticity, excellent low-temperature resistance, on the other hand, it can fully promote the system to mix evenly, which can be beneficial to the subsequent vulcanization of the water stop. The pretreated graphene obtained by the present invention and the reinforcing agent can form a complementary relationship in the substrate, and used as an auxiliary reinforcing agent, which can significantly improve the product's anti-compression deformation, tear resistance and tensile strength.

[0077] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A rubber water stop suitable for low temperature environments in cold region tunnels, characterized in that: The raw materials include, by mass, 100-150 parts of EPDM rubber, 5-15 parts of homopolymer epichlorohydrin rubber, 20-40 parts of acrylate rubber, 1-3 parts of liquid nitrile rubber, 0.01-0.1 parts of phthalic anhydride, 5-10 parts of nano graphene oxide, 1-3 parts of tetraethyl orthosilicate, 1-2 parts of aminosilane, 40-60 parts of reinforcing agent, 1-3 parts of antioxidant, 1-5 parts of plasticizer, 1-2 parts of vulcanizer and 1-2 parts of accelerator.

2. The rubber waterstop suitable for low temperature environment of cold area tunnels according to claim 1 is characterized in that: The aminosilane was gamma-aminopropyltriethoxysilane.

3. The rubber waterstop suitable for low temperature environment of cold area tunnels according to claim 1 is characterized in that: The liquid nitrile rubber is a carboxyl-terminated liquid nitrile rubber.

4. The rubber waterstop suitable for low temperature environment of cold area tunnels according to claim 1 is characterized in that: The reinforcing agent is carbon black N550.

5. The rubber waterstop suitable for low temperature environment of cold area tunnels according to claim 1 is characterized in that: The antioxidant is at least one of antioxidant AW, antioxidant D, antioxidant CPPD, and antioxidant IPPD.

6. The rubber waterstop suitable for low temperature environment of cold area tunnels according to claim 1 is characterized in that: The plasticizer is at least one of dioctyl sebacate, dioctyl phthalate, dioctyl adipate, trioctyl phosphate and dibutyl phthalate.

7. The rubber waterstop suitable for low temperature environment of cold area tunnels according to claim 1 is characterized in that: The vulcanizing agent is sulfur.

8. The rubber waterstop suitable for low temperature environment of cold area tunnels according to claim 1 is characterized in that: The accelerator is at least one of zinc dibutyl dithiocarbamate and tetramethylthiuram disulfide.

9. A method for preparing a rubber waterstop suitable for low-temperature environments in cold-region tunnels as claimed in any one of claims 1 to 8, characterized in that: The steps include: S1. Add nano-graphene oxide to ethanol aqueous solution and stir for 10-30 min, add tetraethyl orthosilicate and aminosilane thereto under stirring, stir at 80-90° C. for 1-2 h, filter, wash, and vacuum dry to obtain pretreated graphene; S2, adding liquid nitrile rubber to an organic solvent and stirring evenly, adding pretreated graphene and phthalic anhydride thereto, stirring at 140-150° C. for 2-4 hours, filtering, vacuum drying, adding ethylene propylene diene rubber, homopolymer chloroether rubber, and acrylate rubber, and mixing at 140-160° C. for 1-3 minutes to obtain a premix; S3. Add reinforcing agent, antioxidant and plasticizer to the premix and mix for 1-2 minutes. Thin it 2-6 times, cool it to 50-60℃, add vulcanizer and accelerator and mix evenly. Extrusion molding and vulcanization at 200-220℃.

10. The method for preparing the rubber waterstop suitable for low temperature environment of cold area tunnels according to claim 9, characterized in that: In S2, the organic solvent is N,N-dimethylformamide.

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