Seawater swelling rubber water stop strip and preparation method thereof

Abstract

The invention relates to the technical field of rubber water-stop strips, and provides a rubber water-stop strip capable of expanding when encountering seawater and a preparation method of the rubber water-stop strip. The invention relates to a rubber water-stop strip capable of expanding when meeting seawater. The rubber water-stop strip is prepared from the following raw material components in parts by mass: 75-110 parts of butyl rubber, 12-40 parts of epoxidized natural rubber, 3-5 parts of a compatilizer, 20-36 parts of a filling agent, 10-30 parts of water-absorbent resin, 5-15 parts of naphthenic oil, 1-5 parts of a coloring agent, 10-20 parts of a reinforcing agent, 0.5-1.5 parts of an anti-aging agent, 1-2 parts of a vulcanizing agent and 1-2 parts of a vulcanization accelerator, the epoxidation degree of the epoxidized natural rubber is 25%-50%. By means of the technical scheme, the problem that in the prior art, the volume expansion rate of the rubber water stop strip expanding when meeting seawater is low is solved.

Description

Technical Field

[0001] The invention relates to the technical field of rubber waterstop strips, and in particular to a rubber waterstop strip that expands when exposed to seawater and a preparation method thereof. Background Art

[0002] In marine engineering, coastal underground facilities and concrete structures in saline soil areas, joint waterproofing has always been a core problem for engineering durability. Traditional water-swelling rubber waterstops use natural rubber or general synthetic rubber as the matrix, combined with water-absorbing materials such as sodium bentonite or sodium polyacrylate, to fill gaps by absorbing water and swelling to achieve waterproofing. However, when such materials are used in seawater or high-salt groundwater environments, their performance faces multiple challenges: salt ions in seawater will combine with the active groups of the water-absorbing resin to form an ion shielding effect, resulting in a significant reduction in water absorption capacity; the rubber matrix swells and softens under long-term immersion in salt solutions, and the interfacial bonding strength with the water-absorbing agent decreases, causing the material to delaminate; at the same time, salt erosion will accelerate the breakage of rubber molecular chains, resulting in degradation of mechanical properties, making it difficult to withstand the stress caused by structural deformation.

[0003] Existing seawater-swelling rubber waterstops face multiple difficulties in material selection and formula design. Although butyl rubber has good salt resistance, its compatibility with polar water absorbents is poor, and a large amount of compatibilizers need to be added, resulting in increased costs and deterioration of processing performance. With the acceleration of my country's marine engineering construction, such as the advancement of cross-sea bridges, undersea tunnels and offshore wind power foundations, the demand for joint waterproofing in high-salt environments is increasing. The volume expansion ratio of the mainstream seawater-swelling rubber waterstop products in seawater still cannot meet engineering needs. Although imported products have stable performance, they are expensive and difficult to achieve economic scale application.

[0004] Therefore, in order to broaden the application scope of the expansion rubber waterstop, it is necessary to develop a seawater expansion rubber waterstop with a high volume expansion ratio. Summary of the invention

[0005] The invention provides a seawater-swelling rubber waterstop strip and a preparation method thereof, which solves the problem of low volume expansion ratio of the seawater-swelling rubber waterstop strip in the related art.

[0006] The technical solution of the present invention is as follows: The invention provides a seawater-swellable rubber waterstop strip, wherein the raw materials include the following components in parts by mass: 75-110 parts of butyl rubber, 12-40 parts of epoxidized natural rubber, 3-5 parts of a compatibilizer, 20-36 parts of a filler, 10-30 parts of a water-absorbent resin, 5-15 parts of naphthenic oil, 1-5 parts of a colorant, 10-20 parts of a reinforcing agent, 0.5-1.5 parts of an antioxidant, 1-2 parts of a vulcanizing agent, and 1-2 parts of a vulcanization accelerator; The epoxidation degree of the epoxidized natural rubber is 25% to 50%.

[0007] As a further technical solution, the mass ratio of the butyl rubber to the epoxidized natural rubber is 3-5:1.

[0008] In the present invention, the mass ratio of butyl rubber to epoxidized natural rubber is controlled at 3 to 5:1, and the comprehensive performance of the material is optimized through the synergistic effect. The butyl rubber provides the main body salt resistance, and the epoxidized natural rubber improves the polarity and processing fluidity. The optimization of the ratio of the two ensures the expansion stability of the material in a high-salt environment, while reducing the cost. Under this ratio, the crosslinking density and elastic modulus of the rubber matrix reach the optimal state, which not only ensures the sealing of the water stop strip under static water pressure, but also can adapt to the needs of dynamic deformation of the structure, and prolong the service life of the rubber water stop strip that expands when encountering seawater.

[0009] In the present invention, the mass ratio of butyl rubber to epoxidized natural rubber can be 3:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1, 4:1, 4.2:1, 4.4:1, 4.6:1, 4.8:1, or 5:1.

[0010] As a further technical solution, the reinforcing agent includes polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66.

[0011] In the present invention, the reinforcing agent adopts a combination of polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66. The polyvinyl alcohol fiber is interwoven into a network with a micron-level diameter in the rubber matrix, and forms a main load-bearing skeleton through physical entanglement, which directly bears the tensile load. The styrene block of the styrene-butadiene-styrene block copolymer forms a rigid micro-region after vulcanization, which limits the slippage of the rubber segment and makes the stress distribution more uniform. The rigid segment of nylon 66 interacts with the rubber molecule through the amide group to form a bonding layer at the interface to prevent the initiation and expansion of cracks. The three construct a synergistic structure of "fiber skeleton-elastomer cross-linking-nano interface", which improves the tensile strength of the rubber waterstop strip that expands when encountering seawater.

[0012] As a further technical solution, the mass ratio of the polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66 is 1:1:0.3~0.6.

[0013] In the present invention, polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66 are compounded in a mass ratio of 1:1:0.3-0.6, thereby maximizing the reinforcement effect. Under this ratio, the reinforcing effect of the polyvinyl alcohol fiber, the plastic deformation of the styrene-butadiene-styrene block copolymer during stretching and the strengthening effect of the rigid particles are balanced, thereby further improving the tensile strength of the rubber waterstop strip that expands when exposed to seawater.

[0014] In the present invention, the mass ratio of polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66 can be 1:1:0.32, 1:1:0.34, 1:1:0.36, 1:1:0.38, 1:1:0.4, 1:1:0.42, 1:1:0.44, 1:1:0.46, 1:1:0.48, 1:1:0.5, 1:1:0.52, 1:1:0.54, 1:1:0.56, 1:1:0.58, and 1:1:0.6.

[0015] As a further technical solution, the compatibilizer includes one or more of chlorinated polyethylene, styrene-ethylene-butylene-styrene block copolymer, and polymethyl acrylate.

[0016] In the present invention, the compatibilizer may be any conventional compatibilizer, preferably one of styrene-ethylene-butylene-styrene block copolymer, polymethyl acrylate, and chlorinated polyethylene.

[0017] In the present invention, the compatibilizer plays a key role. The compatibilizer forms an interfacial force with the non-polar side methyl groups of the butyl rubber and the epoxy groups of the epoxidized natural rubber, effectively improving the compatibility of the two rubber matrices, promoting the uniform dispersion of the two phases, and avoiding the common phase separation problem in the traditional blending process. This molecular-level combination significantly enhances the interfacial strength of the material, so that the seawater-expandable rubber waterstop strip can withstand greater stress during the water absorption and expansion process without delamination, thereby ensuring the stability of the long-term sealing performance.

[0018] As a further technical solution, the filler includes one or more of bentonite, calcium carbonate, and carbon black.

[0019] In the present invention, the filler may be any conventional filler, and may be one of bentonite, calcium carbonate, carbon black, silicon dioxide, and talc, and is preferably one of bentonite, calcium carbonate, and carbon black.

[0020] In the present invention, the filler is evenly dispersed in the rubber matrix in a reasonable proportion, and its rigid particles form physical cross-linking points during the vulcanization process, thereby enhancing the internal stress transfer efficiency of the material and optimizing the mechanical properties of the rubber. The surface active sites of the filler interact with the resin molecules to slow down the water absorption and expansion rate and maintain the structural stability of the material, thereby ensuring that the water stop strip can be effectively sealed without losing mechanical properties when encountering seawater. In addition, the addition of the filler improves the processing fluidity of the rubber matrix, making it easier for the material to fill complex molds during extrusion molding, while reducing production costs and improving product economy.

[0021] As a further technical solution, the water-absorbent resin includes sodium polyacrylate.

[0022] In the present invention, the water-absorbent resin may be any one or more conventional water-absorbent resins, preferably sodium polyacrylate.

[0023] In the present invention, the molecular chain of the water-absorbent resin is rich in hydrophilic groups. When encountering seawater, it quickly absorbs water and expands in volume to form an elastic gel layer, actively filling concrete cracks and interface gaps, and blocking the seawater penetration path. This dynamic sealing mechanism allows the waterstop strip to remain in a continuous elastic state after absorbing water, forming a watertight barrier and avoiding rigid expansion and cracking. The resin and the rubber matrix form an interlocking structure through interfacial hydrogen bonds or chemical grafting, ensuring that particles do not fall off and the gel does not collapse during the expansion process, maintaining the overall mechanical stability of the material. During long-term immersion in seawater, the three-dimensional network structure of the resin inhibits salt ion erosion, maintains the reversibility of expansion, and adapts to repeated dry-wet cycles in a tidal environment.

[0024] As a further technical solution, the colorant includes one of titanium dioxide and zinc oxide.

[0025] In the present invention, the colorant may be any one or more conventional colorants, preferably one of zinc oxide and titanium dioxide.

[0026] In the present invention, the colorant is a key component of the product appearance. It is evenly dispersed in the rubber matrix, giving the material a bright color for easy identification during engineering construction. The high hiding power of the colorant ensures consistent color on the surface of the product and avoids visual defects caused by light transmission. The colorant can also delay photo-oxidation aging of the material. This design enables the water stop strip to maintain a bright color during long-term outdoor service, while improving the weather resistance and mechanical durability of the material from the essence of the material. It is particularly suitable for sealing structures of water conservancy projects in exposed environments, which not only meets the aesthetic requirements but also ensures functional reliability.

[0027] As a further technical solution, the antioxidant includes one of antioxidant D, antioxidant MB, and antioxidant TMQ.

[0028] In the present invention, the antioxidant may be any conventional antioxidant, preferably antioxidant D, antioxidant MB, and antioxidant TMQ.

[0029] In the present invention, the antioxidant significantly improves the aging resistance of the seawater-expandable rubber waterstop strip through free radical capture and oxidation inhibition. As a key anti-aging component, the active groups in the molecular structure of the antioxidant can effectively capture the free radicals generated during the oxidation of the rubber, interrupt the chain degradation reaction, and delay the breakage of the molecular chain. The antioxidant also covers the rubber surface through chemical adsorption to form a protective film to isolate oxygen and moisture, inhibiting photo-oxidative aging and hydrolysis reactions. In the seawater environment, the alkaline group of the antioxidant neutralizes chloride ion corrosion, and its hydrophobic structure reduces electrolyte penetration, maintains the stability of the material cross-linking network, and enables the waterstop strip to maintain stable mechanical properties under long-term humidity, heat, salt spray and ultraviolet radiation. It is particularly suitable for sealing structures exposed to complex environments in cross-sea projects, and extends the service life of the waterstop system from the material essence.

[0030] As a further technical solution, the vulcanizing agent includes one of dicumyl peroxide, di-tert-butyl dicumyl peroxide, and sulfur.

[0031] In the present invention, the vulcanizing agent can be any conventional vulcanizing agent, and the vulcanizing agent can be one of di-tert-butyl diisopropylbenzene peroxide, sulfur, dibenzoylquinone dioxime, and diisopropylbenzene peroxide, preferably one of diisopropylbenzene peroxide, di-tert-butyl diisopropylbenzene peroxide, and sulfur.

[0032] In the present invention, the vulcanizing agent serves as a key component for rubber vulcanization, and its active groups initiate a cross-linking reaction under heating conditions, forming a three-dimensional network structure between rubber molecular chains, giving the material high elasticity and deformation resistance. This cross-linking network enables the seawater-swelling rubber waterstop strip to produce reversible elastic deformation when subjected to force, and quickly returns to its original state after unloading, effectively compensating for the displacement and deformation of the concrete structure. The cross-linking density of the vulcanizing agent directly affects the mechanical properties of the material: moderate cross-linking can balance the tensile strength and elongation at break, so that the seawater-swelling rubber waterstop strip has sufficient rigidity to resist water pressure while maintaining flexibility. In addition, the chemical stability of the cross-linking network significantly improves the environmental resistance of the material, delays the breakage of molecular chains caused by factors such as high temperature and seawater erosion, and ensures that the waterstop strip maintains sealing performance for a long time under complex working conditions.

[0033] As a further technical solution, the vulcanization accelerator includes one of accelerator PZ, accelerator EZ and accelerator D.

[0034] In the present invention, the vulcanization accelerator may be any conventional vulcanization accelerator, and the vulcanization accelerator may be one of accelerator PZ, accelerator EZ, accelerator D, accelerator M, accelerator DM, accelerator CZ, and accelerator BZ, preferably one of accelerator PZ, accelerator EZ, and accelerator D.

[0035] In the present invention, the vulcanization accelerator is used as a key auxiliary agent for rubber vulcanization. Its active sites accelerate the cross-linking reaction during the vulcanization process, reduce the reaction activation energy, shorten the vulcanization cycle and improve the production efficiency. The vulcanization accelerator forms a more uniform three-dimensional network structure between rubber molecular chains by regulating the cross-linking network formation process, thereby optimizing the mechanical properties of the material: a moderate cross-linking density balances the tensile strength and the elongation at break, and improves the deformation resistance and resilience of the material. In a seawater environment, the accelerator and the vulcanizer work synergistically to form a cross-linking bond with higher chemical stability, inhibit salt ion corrosion, and delay the aging process of the material.

[0036] The present invention also provides a method for preparing a seawater-swellable rubber waterstop strip, which is used to prepare the seawater-swellable rubber waterstop strip, comprising the following steps: S1, mixing butyl rubber, epoxidized natural rubber, compatibilizer, filler, water-absorbing resin, naphthenic oil, colorant, reinforcing agent, vulcanizing agent, antioxidant and vulcanization accelerator to obtain a rubber mixture; S2, extruding the mixed rubber and vulcanizing it to obtain a rubber waterstop strip that swells when exposed to seawater.

[0037] In the present invention, the preparation method uses a one-step mixing process to evenly disperse all components to ensure the uniformity of material performance. During the mixing process, the components fully contact and react, the compatibilizer promotes interface bonding, the reinforcing agent is evenly distributed to form a reinforced network, the water-absorbent resin is fully wrapped by the rubber matrix to avoid agglomeration during water absorption, and the mixed rubber is directly extruded to simplify the production process and improve production efficiency. At the same time, it is ensured that the cross-sectional size of the rubber waterstop strip that expands when encountering seawater is accurate, the surface is smooth, and it is easy to construct and install.

[0038] As a further technical solution, the mixing time is 12 to 18 minutes.

[0039] In the present invention, the mixing time of 12 to 18 minutes ensures that the components are fully mixed, while avoiding excessive shearing that causes the rubber molecular chain to break. In the early stage of mixing, high shear force causes the filler and the water-absorbing resin surface to adsorb the rubber molecular chain; in the middle stage, the reinforcing agent is evenly dispersed; in the later stage, the antioxidant and the vulcanizing agent diffuse to the interface to form a pre-crosslinked structure. This time control ensures the fluidity of the subsequent extrusion process. Too long mixing time will cause the epoxy group of the epoxidized natural rubber to hydrolyze prematurely, reducing water resistance; too short mixing time will cause the filler to be unevenly dispersed, affecting the material performance.

[0040] The working principle and beneficial effects of the present invention are: In the present invention, butyl rubber and epoxidized natural rubber act synergistically, and the two rubbers have different polarities. The epoxidized natural rubber with strong polarity has a strong force on water molecules in seawater, and can weaken the inhibitory effect of cations in seawater on water molecules within an appropriate range. Butyl rubber itself has good salt resistance, and epoxidized natural rubber with an epoxidation degree of 25% to 50% is used to achieve a balance between polarity and elasticity, which not only enhances the compatibility with butyl rubber, but also retains the high elasticity of natural rubber. The butyl rubber and epoxidized natural rubber act synergistically, so that the seawater-swelling rubber waterstop strip can withstand large deformation without breaking during the expansion process, thereby improving the volume expansion ratio of the seawater-swelling rubber waterstop strip, meeting the demand for the volume expansion ratio of the seawater-swelling rubber waterstop strip, and solving the problem of low volume expansion ratio of the existing seawater-swelling rubber waterstop strip. DETAILED DESCRIPTION

[0041] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] In the following embodiments and comparative examples, the model of butyl rubber is Exxon Butyl 268, the model of epoxidized natural rubber with an epoxidation degree of 50% is ENR-50, the model of epoxidized natural rubber with an epoxidation degree of 25% is ENR-25, and the model of epoxidized natural rubber with an epoxidation degree of 75% is ENR-75. The model of chlorinated polyethylene is Yaxing CPE 140B, the model of sodium polyacrylate is ACUSOL 445N, the model of naphthenic oil is K30, the model of polyvinyl alcohol fiber is PVA-117, the model of styrene-ethylene-butylene-styrene block copolymer is G1650, polymethyl acrylate is purchased from Hubei Jusheng Technology Co., Ltd., the item number is JS0247, the model of styrene-butadiene-styrene block copolymer is Baling YH-792E, the model of nylon 66 is ARV 250AE, and the model of nylon 1010 is Zytel® RS LC1000 BK385.

[0043] Example 1 A seawater-swellable rubber waterstop, comprising the following components in parts by mass: 110 parts of butyl rubber, 40 parts of epoxidized natural rubber with an epoxidation degree of 50%, 5 parts of chlorinated polyethylene, 36 parts of bentonite, 30 parts of sodium polyacrylate, 15 parts of naphthenic oil, 5 parts of titanium dioxide, 20 parts of reinforcing agent, 1.5 parts of antioxidant D, 2 parts of diisopropylbenzene peroxide, and 2 parts of accelerator PZ; The reinforcing agent includes polyvinyl alcohol fiber and styrene-butadiene-styrene block copolymer in a mass ratio of 1:1; The method for preparing a rubber waterstop strip that expands when exposed to seawater comprises the following steps: S1, taking butyl rubber, epoxidized natural rubber with an epoxidation degree of 50%, chlorinated polyethylene, bentonite, sodium polyacrylate, naphthenic oil, titanium dioxide, reinforcing agent, antioxidant D, diisopropylbenzene peroxide, and accelerator PZ, and mixing them for 18 minutes to obtain a mixed rubber; S2. Extruding and vulcanizing the mixed rubber to obtain a rubber waterstop strip that swells when exposed to seawater.

[0044] Example 2 A seawater-swellable rubber waterstop, comprising the following components in parts by mass: 75 parts of butyl rubber, 12 parts of epoxidized natural rubber with an epoxidation degree of 50%, 3 parts of styrene-ethylene-butylene-styrene block copolymer, 20 parts of calcium carbonate, 10 parts of sodium polyacrylate, 5 parts of naphthenic oil, 1 part of zinc oxide, 10 parts of reinforcing agent, 0.5 parts of antioxidant MB, 1 part of di-tert-butyl peroxide diisopropylbenzene, and 1 part of accelerator EZ; The reinforcing agent includes polyvinyl alcohol fiber and styrene-butadiene-styrene block copolymer in a mass ratio of 1:1; The method for preparing a rubber waterstop strip that expands when exposed to seawater comprises the following steps: S1, taking butyl rubber, epoxidized natural rubber with an epoxidation degree of 50%, styrene-ethylene-butylene-styrene block copolymer, calcium carbonate, sodium polyacrylate, naphthenic oil, zinc oxide, reinforcing agent, antioxidant MB, di-tert-butyl peroxide diisopropylbenzene, and accelerator EZ, and mixing them for 12 minutes to obtain a mixed rubber; S2. Extruding and vulcanizing the mixed rubber to obtain a rubber waterstop strip that swells when exposed to seawater.

[0045] Example 3 A seawater-swellable rubber waterstop, comprising the following components in parts by mass: 105 parts of butyl rubber, 15 parts of epoxidized natural rubber with an epoxidation degree of 50%, 4 parts of polymethyl acrylate, 28 parts of carbon black, 20 parts of sodium polyacrylate, 10 parts of naphthenic oil, 3 parts of titanium dioxide, 15 parts of reinforcing agent, 1 part of antioxidant TMQ, 1.5 parts of sulfur, and 1.5 parts of accelerator D; The reinforcing agent includes polyvinyl alcohol fiber and styrene-butadiene-styrene block copolymer in a mass ratio of 1:1; The method for preparing a rubber waterstop strip that expands when exposed to seawater comprises the following steps: S1, taking butyl rubber, epoxidized natural rubber with an epoxidation degree of 50%, polymethyl acrylate, carbon black, sodium polyacrylate, 10 parts of naphthenic oil, titanium dioxide, reinforcing agent, antioxidant TMQ, sulfur, and accelerator D, and mixing for 16 minutes to obtain a mixed rubber; S2. Extruding and vulcanizing the mixed rubber to obtain a rubber waterstop strip that swells when exposed to seawater.

[0046] Example 4 The only difference between this embodiment and embodiment 3 is that the epoxidized natural rubber with an epoxidation degree of 50% in this embodiment is replaced by the epoxidized natural rubber with an epoxidation degree of 25%.

[0047] Example 5 The difference between this embodiment and embodiment 4 is that the raw materials of the seawater-swellable rubber waterstop strip in this embodiment include the following components in parts by mass: 80 parts of butyl rubber, 40 parts of epoxidized natural rubber with an epoxidation degree of 25%, 4 parts of polymethyl acrylate, 28 parts of carbon black, 20 parts of sodium polyacrylate, 10 parts of cyclohexane oil, 3 parts of titanium dioxide, 15 parts of reinforcing agent, 1 part of antioxidant TMQ, 1.5 parts of sulfur, and 1.5 parts of accelerator D.

[0048] Example 6 The only difference between this embodiment and embodiment 3 is that the raw materials of the seawater-swellable rubber waterstop strip in this embodiment include the following components in parts by mass: 90 parts of butyl rubber, 30 parts of epoxidized natural rubber with an epoxidation degree of 25%, 4 parts of polymethyl acrylate, 28 parts of carbon black, 20 parts of sodium polyacrylate, 10 parts of cyclohexane oil, 3 parts of titanium dioxide, 15 parts of reinforcing agent, 1 part of antioxidant TMQ, 1.5 parts of sulfur, and 1.5 parts of accelerator D.

[0049] Example 7 The only difference between this embodiment and embodiment 3 is that the raw materials of the seawater-swellable rubber waterstop strip in this embodiment include the following components in parts by mass: 100 parts of butyl rubber, 20 parts of epoxidized natural rubber with an epoxidation degree of 25%, 4 parts of polymethyl acrylate, 28 parts of carbon black, 20 parts of sodium polyacrylate, 10 parts of cyclohexane oil, 3 parts of titanium dioxide, 15 parts of reinforcing agent, 1 part of antioxidant TMQ, 1.5 parts of sulfur, and 1.5 parts of accelerator D.

[0050] Example 8 The only difference between this embodiment and embodiment 7 is that the reinforcing agent in this embodiment includes polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66 in a mass ratio of 1:1:0.6.

[0051] Example 9 The only difference between this embodiment and embodiment 7 is that the reinforcing agent in this embodiment includes polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66 in a mass ratio of 1:1:0.3.

[0052] Example 10 The only difference between this embodiment and embodiment 9 is that nylon 66 in this embodiment is replaced by nylon 1010 of equal mass.

[0053] Embodiment 11 The only difference between this embodiment and embodiment 8 is that the reinforcing agent in this embodiment includes polyvinyl alcohol fiber and nylon 66 in a mass ratio of 2:0.6.

[0054] Example 12 The only difference between this embodiment and embodiment 8 is that the reinforcing agent in this embodiment includes styrene-butadiene-styrene block copolymer and nylon 66 in a mass ratio of 2:0.6.

[0055] Comparative Example 1 The difference between this comparative example and Example 3 is that the raw materials of the seawater-swellable rubber waterstop in this comparative example include the following components in parts by mass: 120 parts of butyl rubber, 4 parts of polymethyl acrylate, 28 parts of carbon black, 20 parts of sodium polyacrylate, 10 parts of cyclohexane oil, 3 parts of titanium dioxide, 15 parts of reinforcing agent, 1 part of antioxidant TMQ, 1.5 parts of sulfur, and 1.5 parts of accelerator D.

[0056] Comparative Example 2 The difference between this comparative example and Example 3 is that the raw materials of the seawater-swellable rubber waterstop in this comparative example include the following components in parts by mass: 120 parts of epoxidized natural rubber with an epoxidation degree of 50%, 4 parts of polymethyl acrylate, 28 parts of carbon black, 20 parts of sodium polyacrylate, 10 parts of cyclohexane oil, 3 parts of titanium dioxide, 15 parts of reinforcing agent, 1 part of antioxidant TMQ, 1.5 parts of sulfur, and 1.5 parts of accelerator D.

[0057] Comparative Example 3 The only difference between this comparative example and Example 3 is that in this comparative example, the epoxidized natural rubber with an epoxidation degree of 50% is replaced by an equal mass of epoxidized natural rubber with an epoxidation degree of 75%.

[0058] Experimental Example 1 The volume expansion ratio of the seawater-swellable rubber waterstop strips prepared in Examples 1 to 7 and Comparative Examples 1 to 3 was tested by using saline water with a sodium chloride content of 200 g / L as the soaking water and referring to the test method I specified in GB / T 18173.3-2014 "Polymer Waterproof Materials Part 3: Water-Swellable Rubber" for the rest. The test results are shown in Table 1.

[0059] Table 1 Volume expansion ratio test results

[0060] It can be seen from Table 1 that the volume expansion ratio of the seawater-swellable rubber waterstop strips prepared in Examples 1 to 7 of the present invention reaches more than 465%, and from the comparison between Example 3 and Comparative Examples 1 to 3, it can be seen that the butyl rubber and the epoxidized natural rubber with an epoxidation degree of 25% to 50% in the present invention act synergistically to increase the volume expansion ratio of the seawater-swellable rubber waterstop strips.

[0061] Experimental Example 2 The tensile strength of the seawater-swellable rubber waterstop strips prepared in Examples 7 to 10 was tested according to the method specified in GB / T 18173.3-2014 "Polymer Waterproof Materials Part 3: Water-Swellable Rubber". The test results are shown in Table 2.

[0062] Table 2 Tensile strength test results

[0063] It can be seen from Table 2 that the tensile strength of the rubber waterstop strips that swell when exposed to seawater prepared in Examples 8 to 9 of the present invention reaches more than 14.1 MPa. Therefore, in the present invention, polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66 are used together as reinforcing agents to improve the tensile strength of the rubber waterstop strips that swell when exposed to seawater.

[0064] Experimental Example 3 The seawater-swellable rubber waterstop strips prepared in Example 7 and Example 9 were tested for Shore hardness and elongation at break according to the method specified in GB / T 18173.3-2014 "Polymer Waterproof Materials Part 3: Water-Swellable Rubber". The test results are shown in Table 3.

[0065] Table 3 Shore hardness and elongation at break test results

[0066] It can be seen from Table 3 that the seawater-swelling rubber waterstop strip prepared by the present invention can meet actual use requirements.

[0067] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rubber waterstop strip that expands when exposed to seawater, characterized in that: The raw materials include the following components in parts by weight: 75-110 parts of butyl rubber, 12-40 parts of epoxidized natural rubber, 3-5 parts of compatibilizer, 20-36 parts of filler, 10-30 parts of water-absorbent resin, 5-15 parts of naphthenic oil, 1-5 parts of colorant, 10-20 parts of reinforcing agent, 0.5-1.5 parts of antioxidant, 1-2 parts of vulcanizing agent, and 1-2 parts of vulcanization accelerator; The epoxidation degree of the epoxidized natural rubber is 25% to 50%.

2. The seawater-swellable rubber waterstop according to claim 1, characterized in that: The mass ratio of the butyl rubber to the epoxidized natural rubber is 3-5:

1.

3. The seawater-swellable rubber waterstop according to claim 1, characterized in that: The reinforcing agent includes polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66.

4. The seawater-swellable rubber waterstop according to claim 3, characterized in that: The mass ratio of the polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66 is 1:1:0.3-0.

6.

5. The seawater-swellable rubber waterstop according to claim 1, characterized in that: The compatibilizer includes one or more of chlorinated polyethylene, styrene-ethylene-butylene-styrene block copolymer, and polymethyl acrylate.

6. The seawater-swellable rubber waterstop according to claim 1, characterized in that: The filler includes one or more of bentonite, calcium carbonate, and carbon black; The water-absorbent resin includes sodium polyacrylate.

7. The seawater-swellable rubber waterstop according to claim 1, characterized in that: The colorant includes one of titanium dioxide and zinc oxide; The antioxidant includes one of antioxidant D, antioxidant MB and antioxidant TMQ.

8. The seawater-swellable rubber waterstop according to claim 1, characterized in that: The vulcanizing agent includes one of diisopropylbenzene peroxide, di-tert-butyl diisopropylbenzene peroxide, and sulfur; The vulcanization accelerator includes one of accelerator PZ, accelerator EZ and accelerator D.

9. A method for preparing a seawater-swellable rubber waterstop strip, used for preparing a seawater-swellable rubber waterstop strip as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: S1, mixing butyl rubber, epoxidized natural rubber, compatibilizer, filler, water-absorbing resin, naphthenic oil, colorant, reinforcing agent, vulcanizing agent, antioxidant, and vulcanization accelerator to obtain a rubber mixture; S2, extruding the mixed rubber and vulcanizing it to obtain a rubber waterstop strip that swells when exposed to seawater.

10. The method for preparing a seawater-swellable rubber waterstop strip according to claim 9, characterized in that: The mixing time is 12 to 18 minutes.

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