Seawater-expanding rubber waterstop and preparation method thereof

Abstract

The present invention relates to the technical field of rubber waterstop strips, and proposes a seawater-swelling rubber waterstop strip and a preparation method thereof. The seawater-swelling rubber waterstop strip comprises the following raw materials in parts by weight: 75-110 parts butyl rubber, 12-40 parts epoxidized natural rubber, 3-5 parts compatibilizer, 20-36 parts filler, 10-30 parts water-absorbent resin, 5-15 parts naphthenic oil, 1-5 parts colorant, 10-20 parts reinforcing agent, 0.5-1.5 parts antioxidant, 1-2 parts vulcanizing agent, and 1-2 parts vulcanization accelerator; the epoxidized natural rubber has an epoxidation degree of 25%-50%. This technical solution solves the problem of low volume expansion ratio of seawater-swelling rubber waterstop strips in the related art.

Description

Technical Field

[0001] The present 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 in project durability. Traditional water-swelling rubber waterstops use natural rubber or general-purpose synthetic rubber as a matrix, combined with water-absorbing materials such as sodium bentonite or sodium polyacrylate, to achieve waterproofing by filling gaps through water absorption and expansion. 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 will swell and soften under long-term immersion in salt solutions, and the interfacial bonding strength with the water-absorbing agent will decrease, causing the material to delaminate; at the same time, salt corrosion will accelerate the breakage of rubber molecular chains, resulting in the 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 formulation design. Although butyl rubber has good salt resistance, its compatibility with polar water absorbents is poor, requiring the addition of large amounts of compatibilizers, resulting in increased costs and deteriorating processing performance. With the acceleration of marine engineering construction in my country, such as 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 mainstream seawater-swelling rubber waterstop products in seawater still cannot meet engineering requirements. Although imported products have stable performance, they are expensive, making them difficult to apply on an economical scale.

[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 present invention provides a seawater-expanding rubber waterstop and a preparation method thereof, which solves the problem of low volume expansion ratio of seawater-expanding rubber waterstop in the related art.

[0006] The technical solutions of the present invention are as follows:

[0007] The present invention provides a seawater-swelling rubber waterstop strip, the raw materials of which 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-absorbing 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;

[0008] The epoxidation degree of the epoxidized natural rubber is 25% to 50%.

[0009] As a further technical solution, the mass ratio of the butyl rubber to the epoxidized natural rubber is 3-5:1.

[0010] In this invention, the mass ratio of butyl rubber to epoxidized natural rubber is controlled at 3-5:1. This synergistic effect optimizes the material's overall performance: the butyl rubber provides salt tolerance, while the epoxidized natural rubber improves polarity and processing fluidity. This optimized ratio ensures the material's expansion stability in high-salt environments while reducing costs. At this ratio, the crosslink density and elastic modulus of the rubber matrix are optimized, ensuring the waterstop's sealing performance under static water pressure while also adapting to dynamic structural deformation, extending the service life of the seawater-expanding rubber waterstop.

[0011] 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.

[0012] As a further technical solution, the reinforcing agent includes polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66.

[0013] 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 molecules through the amide group, forming 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 that expands when exposed to seawater.

[0014] 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.

[0015] 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 to maximize the reinforcement effect. At 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, further improving the tensile strength of the rubber waterstop that expands when exposed to seawater.

[0016] 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.

[0017] As a further technical solution, the compatibilizer includes one or more of chlorinated polyethylene, styrene-ethylene-butylene-styrene block copolymer, and polymethyl acrylate.

[0018] In the present invention, the compatibilizer can be any conventional compatibilizer, preferably one of styrene-ethylene-butylene-styrene block copolymer, polymethyl acrylate, and chlorinated polyethylene.

[0019] 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 uniform dispersion of the two phases, and avoiding the phase separation problem commonly seen in traditional blending processes. This molecular-level bonding significantly enhances the interfacial strength of the material, enabling the seawater-expandable rubber waterstop to withstand greater stress during the water absorption and expansion process without delamination, thereby ensuring the long-term stability of the sealing performance.

[0020] As a further technical solution, the filler includes one or more of bentonite, calcium carbonate, and carbon black.

[0021] 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, preferably one of bentonite, calcium carbonate, and carbon black.

[0022] 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 transmission efficiency of the material and optimizing the mechanical properties of the rubber. The surface active sites of the filler interact with the resin molecules, slowing the water absorption and expansion rate and maintaining the structural stability of the material, ensuring that the waterstop 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.

[0023] As a further technical solution, the water-absorbing resin includes sodium polyacrylate.

[0024] In the present invention, the water-absorbing resin may be any one or more conventional water-absorbing resins, preferably sodium polyacrylate.

[0025] 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 interfacial gaps, blocking the seawater penetration path. This dynamic sealing mechanism enables the waterstop strip to remain in a continuous elastic state after absorbing water, forming a watertight barrier while avoiding rigid 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 tidal environments.

[0026] As a further technical solution, the colorant includes one of titanium dioxide and zinc oxide.

[0027] In the present invention, the colorant may be any one or more conventional colorants, preferably one of zinc oxide and titanium dioxide.

[0028] 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, avoiding visual defects caused by light transmission. The colorant can also delay photooxidative aging of the material. This design enables the water stop 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.

[0029] As a further technical solution, the antioxidant includes one of antioxidant D, antioxidant MB, and antioxidant TMQ.

[0030] In the present invention, the antioxidant may be any conventional antioxidant, preferably one of antioxidant D, antioxidant MB, and antioxidant TMQ.

[0031] In the present invention, the antioxidant significantly improves the aging resistance of the seawater-expanding 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 a seawater environment, the alkaline groups of the antioxidant neutralize chloride ion corrosion, and its hydrophobic structure reduces electrolyte penetration, maintaining the stability of the material cross-linking network, so that the waterstop strip maintains 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, extending the service life of the waterstop system from the material's essence.

[0032] As a further technical solution, the vulcanizing agent includes one of dicumyl peroxide, di-tert-butyl dicumyl peroxide, and sulfur.

[0033] 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.

[0034] In the present invention, the vulcanizing agent serves as a key component for rubber vulcanization. Its active groups initiate a cross-linking reaction under heating conditions, forming a three-dimensional network structure between the rubber molecular chains, giving the material high elasticity and deformation resistance. This cross-linked network enables the seawater-expanding rubber waterstop to produce reversible elastic deformation when subjected to force, and quickly return to its original shape 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-expanding rubber waterstop can maintain flexibility while having sufficient rigidity to resist water pressure. In addition, the chemical stability of the cross-linked 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 maintains sealing performance for a long time under complex working conditions.

[0035] As a further technical solution, the vulcanization accelerator includes one of accelerator PZ, accelerator EZ, and accelerator D.

[0036] In the present invention, the vulcanization accelerator can be any conventional vulcanization accelerator, and the vulcanization accelerator can 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.

[0037] In the present invention, the vulcanization accelerator serves 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 production efficiency. The vulcanization accelerator regulates the cross-linking network formation process to form a more uniform three-dimensional network structure between rubber molecular chains, thereby optimizing the mechanical properties of the material: a moderate cross-linking density balances the tensile strength and elongation at break, improving the material's deformation resistance and resilience. In a seawater environment, the accelerator and the vulcanizer work synergistically to form cross-linked bonds with higher chemical stability, inhibit salt ion corrosion, and delay the aging process of the material.

[0038] The present invention also provides a method for preparing a seawater-swelling rubber waterstop strip, which comprises the following steps:

[0039] S1, taking butyl rubber, epoxidized natural rubber, compatibilizer, filler, water-absorbing resin, naphthenic oil, colorant, reinforcing agent, vulcanizing agent, antioxidant, and vulcanization accelerator and mixing them to obtain a rubber compound;

[0040] S2. Extruding the rubber mixture and vulcanizing it to obtain a seawater-swellable rubber waterstop.

[0041] In the present invention, the preparation method uniformly disperses all components through a one-step mixing process to ensure the uniformity of material properties. 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-absorbing resin is fully wrapped by the rubber matrix, and agglomeration during water absorption is avoided. The mixed rubber is directly extruded and formed, which simplifies the production process and improves production efficiency. At the same time, it ensures that the cross-sectional size of the rubber waterstop strip that expands when exposed to seawater is accurate and the surface is smooth, which is convenient for construction and installation.

[0042] As a further technical solution, the mixing time is 12 to 18 minutes.

[0043] In the present invention, a mixing time of 12 to 18 minutes ensures thorough mixing of all components while preventing excessive shearing that could break the rubber chains. In the initial mixing phase, high shear forces cause the filler and water-absorbing resin to adsorb rubber chains onto their surfaces; in the middle phase, the reinforcing agent is evenly dispersed; and in the later phase, the antioxidant and vulcanizing agent diffuse to the interface, forming a pre-crosslinked structure. This time control ensures fluidity during the subsequent extrusion process. Excessive mixing times can prematurely hydrolyze the epoxy groups in the epoxidized natural rubber, reducing water resistance; while too short mixing times can lead to uneven filler dispersion, affecting material properties.

[0044] The working principle and beneficial effects of the present invention are:

[0045] In the present invention, butyl rubber and epoxidized natural rubber act synergistically. The two rubbers have different polarities. The epoxidized natural rubber with strong polarity exerts 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. In addition, epoxidized natural rubber with an epoxidation degree of 25% to 50% is used to achieve a balance between polarity and elasticity, thereby enhancing the compatibility with butyl rubber and retaining 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

[0046] 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 embodiments described 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 making any creative efforts are within the scope of protection of the present invention.

[0047] In the following examples 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.

[0048] Example 1

[0049] A seawater-swelling rubber waterstop, comprising the following components in parts by weight: 110 parts of butyl rubber, 40 parts of epoxidized natural rubber with a 50% epoxidation degree, 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 a reinforcing agent, 1.5 parts of an antioxidant D, 2 parts of dicumyl peroxide, and 2 parts of an accelerator PZ.

[0050] The reinforcing agent includes polyvinyl alcohol fiber and styrene-butadiene-styrene block copolymer in a mass ratio of 1:1;

[0051] The preparation method of the seawater-swellable rubber waterstop comprises the following steps:

[0052] S1. Take butyl rubber, epoxidized natural rubber with an epoxidation degree of 50%, chlorinated polyethylene, bentonite, sodium polyacrylate, naphthenic oil, titanium dioxide, reinforcing agent, antioxidant D, dicumyl peroxide, and accelerator PZ and mix them for 18 minutes to obtain a rubber mixture;

[0053] S2. Extruding the mixed rubber and vulcanizing it to obtain a rubber waterstop that expands when exposed to seawater.

[0054] Example 2

[0055] A seawater-swelling rubber waterstop, comprising the following components in parts by mass: 75 parts of butyl rubber, 12 parts of epoxidized natural rubber with a degree of epoxidation 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 a reinforcing agent, 0.5 parts of an antioxidant MB, 1 part of di-tert-butyl diisopropylbenzene peroxide, and 1 part of an accelerator EZ.

[0056] The reinforcing agent includes polyvinyl alcohol fiber and styrene-butadiene-styrene block copolymer in a mass ratio of 1:1;

[0057] The preparation method of the seawater-swellable rubber waterstop comprises the following steps:

[0058] 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 diisopropylbenzene peroxide, and accelerator EZ, and mixing them for 12 minutes to obtain a rubber compound;

[0059] S2. Extruding the mixed rubber and vulcanizing it to obtain a rubber waterstop that expands when exposed to seawater.

[0060] Example 3

[0061] A seawater-swelling rubber waterstop, comprising the following components in parts by mass: 105 parts of butyl rubber, 15 parts of epoxidized natural rubber with a degree of epoxidation 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 a reinforcing agent, 1 part of an antioxidant TMQ, 1.5 parts of sulfur, and 1.5 parts of an accelerator D;

[0062] The reinforcing agent includes polyvinyl alcohol fiber and styrene-butadiene-styrene block copolymer in a mass ratio of 1:1;

[0063] The preparation method of the seawater-swellable rubber waterstop comprises the following steps:

[0064] 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 them for 16 minutes to obtain a rubber mixture;

[0065] S2. Extruding the mixed rubber and vulcanizing it to obtain a rubber waterstop that expands when exposed to seawater.

[0066] Example 4

[0067] 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 epoxidized natural rubber with an epoxidation degree of 25%.

[0068] Example 5

[0069] The only difference between this embodiment and embodiment 4 is that the raw materials of the seawater-swellable rubber waterstop 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.

[0070] Example 6

[0071] The only difference between this embodiment and embodiment 3 is that the raw materials of the seawater-swellable rubber waterstop 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.

[0072] Example 7

[0073] The only difference between this embodiment and embodiment 3 is that the raw materials of the seawater-swellable rubber waterstop 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.

[0074] Example 8

[0075] 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.

[0076] Example 9

[0077] 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.

[0078] Example 10

[0079] The only difference between this embodiment and embodiment 9 is that nylon 66 in this embodiment is replaced by nylon 1010 of equal mass.

[0080] Example 11

[0081] 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.

[0082] Example 12

[0083] 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.

[0084] Comparative Example 1

[0085] The only difference between this comparative example and Example 3 is that the raw materials of the seawater-swelling 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.

[0086] Comparative Example 2

[0087] The only 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 a reinforcing agent, 1 part of an antioxidant TMQ, 1.5 parts of sulfur, and 1.5 parts of an accelerator D.

[0088] Comparative Example 3

[0089] 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%.

[0090] Experimental Example 1

[0091] The volume expansion ratios of the seawater-swellable rubber waterstops prepared in Examples 1-7 and Comparative Examples 1-3 were tested using saline solution with a sodium chloride content of 200 g / L as the soaking water, following the test method I specified in GB / T 18173.3-2014, "Polymer Waterproof Materials - Part 3: Water-Swellable Rubber." The test results are shown in Table 1.

[0092] Table 1 Volume expansion ratio test results

[0093]

[0094] As can be seen from Table 1, the volume expansion ratio of the seawater-swelling 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 work synergistically to increase the volume expansion ratio of the seawater-swelling rubber waterstop strips.

[0095] Experimental Example 2

[0096] The seawater-swellable rubber waterstops prepared in Examples 7 to 10 were tested for tensile strength 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.

[0097] Table 2 Tensile strength test results

[0098]

[0099] As can be seen from Table 2, the tensile strength of the seawater-swelling rubber waterstop strips prepared in Examples 8 to 9 of the present invention reaches more than 14.1 MPa. Therefore, the present invention uses polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66 as reinforcing agents to improve the tensile strength of the seawater-swelling rubber waterstop strips.

[0100] Experimental Example 3

[0101] The seawater-swelling 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-Swelling Rubber". The test results are shown in Table 3.

[0102] Table 3 Shore hardness and elongation at break test results

[0103]

[0104] It can be seen from Table 3 that the seawater-swelling rubber waterstop produced by the present invention can meet actual use requirements.

[0105] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A seawater-expandable rubber waterstop, characterized in that: 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-absorbing 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%; The mass ratio of the butyl rubber to the epoxidized natural rubber is 3 to 5:1; The reinforcing agent includes polyvinyl alcohol fiber, styrene-butadiene-styrene block copolymer and nylon 66.

2. The seawater-swellable rubber waterstop according to claim 1, 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.

3. 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.

4. 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-absorbing resin includes sodium polyacrylate.

5. 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.

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

7. A method for preparing a seawater-swelling rubber waterstop strip, for preparing the seawater-swelling rubber waterstop strip according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, taking butyl rubber, epoxidized natural rubber, compatibilizer, filler, water-absorbing resin, naphthenic oil, colorant, reinforcing agent, vulcanizing agent, antioxidant, and vulcanization accelerator and mixing them to obtain a rubber mixture; S2. Extruding the rubber mixture and vulcanizing it to obtain a seawater-swellable rubber waterstop.

8. The method for preparing a seawater-swellable rubber waterstop according to claim 7, characterized in that: The mixing time is 12 to 18 minutes.

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