A waterstop and a method of making the same

Abstract

The application relates to a waterstop and a preparation method thereof, and raw materials of the waterstop include, in parts by weight, 5-15 parts of eucommia rubber EUG, 85-95 parts of natural rubber, 4-9 parts of an activator, 1-2 parts of an auxiliary activator, 1-4 parts of a chemical antioxidant, 0.5-1.5 parts of a physical antioxidant, 30-50 parts of a reinforcing agent, 20-30 parts of a plasticizer, 5-10 parts of polybutylene terephthalate, 10-20 parts of ethylene-vinyl acetate copolymer, 5-10 parts of potassium hexatitanate whisker, 5-15 parts of polysiloxane boride, 5-10 parts of methyl methacrylate metal zinc, 1-2 parts of DCP, 0.8-1.5 parts of S, 0.5-2 parts of TMTD, 0.5-1.5 parts of DTDM and 1-2 parts of an accelerator DM. The application solves the problems of difficult positioning and high surface friction coefficient caused by too high flexibility and insufficient rigidity of traditional rubber waterstops during construction, and effectively improves the mechanical properties, construction operability and long-term sealing reliability of the waterstop.

Description

Technical Field

[0001] This invention relates to the field of rubber materials technology, specifically to a waterstop and its preparation method. Background Technology

[0002] Rubber waterstops are widely used in the construction of large infrastructure projects such as tunnels, bridges, and basements due to their excellent flexibility. However, their excessive flexibility and insufficient rigidity have caused many problems in actual construction, especially in large-scale projects or complex structures. During the concrete pouring process, the precise positioning and fixing of the waterstop is crucial for waterproofing. Due to its high flexibility, the waterstop is prone to twisting, deformation, or serpentine displacement, making it difficult to maintain the preset installation position and shape. This not only increases the difficulty of operation for construction workers but may also lead to the waterstop not being accurately fixed, affecting its expected waterproofing effect and sealing performance. Simple positioning methods are often unreliable and require additional auxiliary fixing measures. This not only increases the construction process but also raises construction costs, prolongs the construction period, and causes economic and time losses.

[0003] In addition, the high surface friction coefficient of rubber waterstops also has adverse effects during concrete pouring. Due to the high surface friction, concrete is difficult to fully fill and flow on the surface of the waterstop, which easily leads to defects such as voids and gaps around the waterstop. These defects not only directly affect the sealing performance of the waterstop, but may also cause structural leakage during long-term use. In severe cases, secondary repairs are required, increasing maintenance costs and time, and reducing the overall construction quality and project durability. Summary of the Invention

[0004] To address the above technical problems, this invention provides a waterstop and its preparation method. The waterstop of this invention maintains the appropriate flexibility and rigidity of the rubber waterstop, making it easier to operate and fix during installation and construction. At the same time, the waterstop surface has a low coefficient of friction, allowing concrete to flow more smoothly, thereby reducing voids and gaps around the waterstop, improving the sealing effect of the waterstop and the overall waterproof performance of the project.

[0005] In a first aspect, the present invention provides a waterstop, the raw materials of which, by weight, comprise: 5-15 parts of Eucommia ulmoides rubber EUG, 85-95 parts of natural rubber, 4-9 parts of activator, 1-2 parts of co-activator, 1-4 parts of chemical antioxidant, 0.5-1.5 parts of physical antioxidant, 30-50 parts of reinforcing agent, 20-30 parts of plasticizer, 5-10 parts of polybutylene terephthalate, 10-20 parts of ethylene-vinyl acetate copolymer, 5-10 parts of potassium hexatitanate whiskers, 5-15 parts of polyborosiloxane, 5-10 parts of zinc methacrylate, 1-2 parts of DCP, 0.8-1.5 parts of S, 0.5-2 parts of TMTD, 0.5-1.5 parts of DTDM, and 1-2 parts of accelerator DM.

[0006] Preferably, the activator is one of zinc oxide or magnesium oxide;

[0007] Preferably, the VA content in the ethylene-vinyl acetate copolymer is 5%-10%;

[0008] Preferably, the activator is stearic acid;

[0009] Preferably, the reinforcing agent is a combination of carbon black and silica;

[0010] Preferably, the carbon black is one of N330, N550 or N660;

[0011] Preferably, the specific surface area of ​​the silica is 400-500 m². 2 / g, the specific surface area of ​​silica is tested by nitrogen adsorption method;

[0012] Preferably, the plasticizer is one of paraffin oil, naphthenic oil, or engine oil;

[0013] Preferably, the chemical antioxidant is a combination of diphenylamine and phenolic antioxidants;

[0014] Preferably, the chemical antioxidant is a combination of RD and 4010NA;

[0015] Preferably, the physical antioxidant is a wax;

[0016] Preferably, the physical antioxidant is microcrystalline wax;

[0017] Preferably, the polybutylene terephthalate is of model number D202G30-4886.

[0018] Secondly, the present invention provides a method for preparing a waterstop, comprising the following steps:

[0019] S1. Heat the open mill to 30-35℃, set the roll gap to 1-2mm, add Eucommia ulmoides rubber EUG and natural rubber into the open mill and plasticize for 5-10 minutes. Then, after degassing, pressing, and sheeting, cool to room temperature and let stand for 4-5 hours to obtain plasticized rubber.

[0020] S2. Heat the internal mixer to 80-90℃, add the plasticized rubber described in S1, mix for 2-5 minutes, then add the activator, co-activator, chemical antioxidant, physical antioxidant, potassium hexatitanate whiskers and zinc methacrylate in sequence, mix for 1-2 minutes, then add the reinforcing agent, ethylene-vinyl acetate copolymer, polybutylene terephthalate, polyborosiloxane and plasticizer, mix for 3-5 minutes, then discharge the rubber, compress and sheet, cool to room temperature and let stand for 3-5 hours to obtain compound rubber one;

[0021] S3. Add DCP, S, TMTD, DTDM and accelerator DM to the compound obtained in S2. After mixing for 2-3 minutes, discharge the rubber, sheet it, cool it to room temperature and let it stand for 3-5 hours to obtain compound two.

[0022] S4. The compound rubber obtained in S3 is fed into a single screw extruder and extruded to obtain a waterstop tape. Then it is wound up and cooled to obtain the finished product.

[0023] Preferably, the polyborosiloxane is prepared by the following method: it is synthesized by the condensation reaction of hydroxyl-terminated polydimethylsiloxane (PDMS-OH) and boric acid. After accurately weighing 2000g of PDMS-OH and 60-230g of boric acid, PDMS-OH is added to a vacuum kneader and the heating mode is selected. When the temperature is raised to 110°C, boric acid is added to carry out the chemical reaction. After all the reactants are added, the vacuum mode is selected until the temperature is raised to 180°C and the reaction is continued for 2 hours. Then it is cooled to room temperature to obtain polyborosiloxane.

[0024] Preferably, the hydroxyl content of PDMS-OH is 2.5%-9.2%.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The waterstop of the present invention maintains moderate flexibility in the longitudinal direction to adapt to the bending requirements of construction, and has moderate rigidity in the cross-sectional direction to ensure the stability of installation and positioning; the surface friction coefficient is optimized to promote smooth flow during concrete pouring, significantly reduce the risk of hollowness and gaps around the waterstop, and improve the waterproof quality of the project from both the aspects of construction operability and sealing reliability.

[0027] (2) This invention has a dynamic self-healing function. The Eucommia ulmoides rubber EUG crystalline region serves as a physical cross-linking point, endowing the material with initial rigidity and self-healing ability. Under the action of the DCP / sulfur dual cross-linking system, it forms a rigid-flexible interpenetrating network with natural rubber. When the waterstop is subjected to construction compression or micro-damage, the Eucommia ulmoides rubber EUG crystalline phase undergoes a reversible transformation. The molecular chains spontaneously reset under the action of the elastic recovery force of the cross-linking network. After cooling, the crystalline phase is re-fixed to complete the morphological repair. The boron-oxygen weak bonds in the dynamic cross-linking network of polyborosiloxane can achieve autonomous repair through reversible recombination. Its molecular chains slowly slide and rearrange with the help of non-bonded complexation. At the same time, the three-dimensional network reinforced by zinc methacrylate provides structural support. Combined with the rigid skeleton of potassium hexatitanate whiskers, it restricts deformation and ensures that microcracks gradually close at room temperature. The two mechanisms work together to achieve autonomous recovery of the sealing morphology without artificial intervention, effectively extending the waterproof life.

[0028] (3) Zinc methacrylate plays a key reinforcing role in the rubber matrix. By improving the interfacial compatibility between natural rubber and Eucommia ulmoides rubber EUG, it promotes the formation of a three-dimensional cross-network structure, significantly enhances the interfacial bonding force of the composite material, efficiently disperses and transmits external stress, and enables the waterstop to have excellent tensile strength, tear strength and wear resistance at the same time, providing a basic guarantee for the overall mechanical properties.

[0029] (4) A rigid-flexible balanced matrix is ​​constructed using polybutylene terephthalate (PET) and ethylene-vinyl acetate copolymer. PET provides core rigid support with its high crystallinity, ensuring the dimensional stability of the waterstop under construction pressure. ethylene-vinyl acetate copolymer adjusts the material's flexibility and improves processing fluidity to reduce molding difficulty. The resulting "rigid skeleton-flexible connection" composite system fundamentally solves the technical bottleneck of insufficient rigidity in traditional rubber waterstops.

[0030] (5) A synergistic reinforcement system is formed by introducing potassium hexatitanate whiskers and polyborosiloxane. The whiskers, with their high aspect ratio, construct a three-dimensional support network in the matrix, improving the overall mechanical strength through stress dispersion. Polyborosiloxane utilizes boron-oxygen non-bonded complexation to form a dynamic physical cross-linking structure. Its reversible weak bond characteristics can adaptively adjust the molecular chain movement, making it particularly suitable for short-term high-frequency external force scenarios during concrete vibration. Under dynamic stress conditions during construction, boron atoms in polyborosiloxane form Si-O:B weak bonds with oxygen-containing groups on the carbon black surface, effectively anchoring the molecular chain and limiting disordered slippage. This weak bond network quickly "locks" the molecular chain movement, and combined with the molecular chain relaxation effect, consolidates the cross-linking structure, ensuring the waterstop maintains morphological stability during the concrete pouring stage. The dynamic cross-linking of polyborosiloxane and potassium hexatitanate whiskers form a multiple reinforcement mechanism. The former provides instantaneous rigidity response under high-frequency vibration, while the latter achieves uniform stress transmission. The superposition of the two enables the waterstop to simultaneously meet the requirements of static rigidity and dynamic stability, ensuring accurate positioning and long-term structural reliability under complex construction environments.

[0031] (6) Polybutylene terephthalate component further optimizes construction performance by reducing the surface energy of the material. The smooth interface formed by its crystalline structure can significantly reduce the friction coefficient of the waterstop, promote the concrete to fully fill the space around the waterstop during the pouring process, and reduce voids and gaps from the perspective of material surface characteristics. Together with the rigid support system, it ensures the sealing effect of the project. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] Preparation Example 1:

[0034] Polyborosiloxane was prepared as follows: 2000g of PDMS-OH with a hydroxyl content of 2.5% and 60g of boric acid were accurately weighed. PDMS-OH was added to a vacuum kneader, and the heating mode was selected. The vacuum kneader was in a heating and stirring state. When the temperature reached 110℃, boric acid was added to carry out a chemical reaction. After all the reactants were added, the vacuum mode was selected until the temperature reached 180℃. The reaction was continued for 2 hours, and then cooled to room temperature to obtain polyborosiloxane.

[0035] Preparation Example 2:

[0036] Polyborosiloxane was prepared as follows: 2000g of PDMS-OH with a hydroxyl content of 9.2% and 225g of boric acid were accurately weighed, and then PDMS-OH was added to a vacuum kneader. The heating mode was selected, and the vacuum kneader was in a heating and stirring state. When the temperature reached 110℃, boric acid was added to carry out a chemical reaction. After all the reactants were added, the vacuum mode was selected until the temperature reached 180℃. The reaction was continued for 2 hours, and then cooled to room temperature to obtain polyborosiloxane.

[0037] Preparation Example 3:

[0038] Polyborosiloxane is prepared by the following method: 2000g of PDMS-OH with a hydroxyl content of 4% and 100g of boric acid are accurately weighed. PDMS-OH is added to a vacuum kneader, and the heating mode is selected. The vacuum kneader is in a heating and stirring state. When the temperature reaches 110℃, boric acid is added to carry out a chemical reaction. After all reactants are added, the vacuum mode is selected until the temperature reaches 180℃. The reaction is continued for 2 hours, and then cooled to room temperature to obtain polyborosiloxane.

[0039] Example 1:

[0040] A waterstop, the raw materials of which, by weight, include: 5 parts of Eucommia ulmoides rubber EUG, 95 parts of natural rubber, 4 parts of zinc oxide, 1 part of stearic acid, 1 part of RD, 1 part of 4010NA, 0.5 parts of microcrystalline wax, 20 parts of N330, 10 parts of silica (specific surface area of ​​400 m² / g), 20 parts of paraffin oil, 5 parts of polybutylene terephthalate, 10 parts of ethylene-vinyl acetate copolymer (VA content 5%), 5 parts of potassium hexatitanate whiskers, 5 parts of polyborosiloxane (prepared from Preparation Example 1), 5 parts of zinc methacrylate, 1 part of DCP, 0.8 parts of S, 0.5 parts of TMTD, 0.5 parts of DTDM, and 1 part of accelerator DM.

[0041] Example 2:

[0042] A waterstop, the raw materials of which, by weight, include: 15 parts of Eucommia ulmoides rubber EUG, 85 parts of natural rubber, 9 parts of zinc oxide, 2 parts of stearic acid, 2 parts of RD, 2 parts of 4010NA, 1.5 parts of microcrystalline wax, 30 parts of N330, 20 parts of silica (specific surface area 420 m² / g), 30 parts of machine oil, 6 parts of polybutylene terephthalate, 20 parts of ethylene-vinyl acetate copolymer (VA content 5%), 10 parts of potassium hexatitanate whiskers, 15 parts of polyborosiloxane (prepared from Preparation Example 2), 10 parts of zinc methacrylate, 2 parts of DCP, 1.5 parts of S, 2 parts of TMTD, 1.5 parts of DTDM, and 2 parts of accelerator DM.

[0043] Example 3:

[0044] A waterstop, the raw materials of which, by weight, include: 10 parts of Eucommia ulmoides rubber EUG, 90 parts of natural rubber, 5 parts of zinc oxide, 1.5 parts of stearic acid, 1.5 parts of RD, 1.5 parts of 4010NA, 0.8 parts of microcrystalline wax, 25 parts of N330, 15 parts of silica (specific surface area 450 m² / g), 25 parts of naphthenic oil, 7 parts of polybutylene terephthalate, 15 parts of ethylene-vinyl acetate copolymer (VA content 5%), 8 parts of potassium hexatitanate whiskers, 7 parts of polyborosiloxane (prepared from Preparation Example 3), 8 parts of zinc methacrylate, 1.5 parts of DCP, 1.0 part of S, 0.8 parts of TMTD, 0.8 parts of DTDM, and 1.5 parts of accelerator DM.

[0045] Example 4:

[0046] A waterstop, the raw materials of which, by weight, include: 9 parts of Eucommia ulmoides rubber EUG, 91 parts of natural rubber, 4.8 parts of zinc oxide, 1.3 parts of stearic acid, 1.3 parts of RD, 1.3 parts of 4010NA, 0.7 parts of microcrystalline wax, 23 parts of N330, 13 parts of silica (specific surface area 430 m² / g), 23 parts of paraffin oil, 6.5 parts of polybutylene terephthalate, 13 parts of ethylene-vinyl acetate copolymer (VA content 8%), 7 parts of potassium hexatitanate whiskers, 8 parts of polyborosiloxane (prepared from Preparation Example 1), 7 parts of zinc methacrylate, 1.5 parts of DCP, 1.0 parts of S, 0.8 parts of TMTD, 0.8 parts of DTDM, and 1.5 parts of accelerator DM.

[0047] Example 5:

[0048] A waterstop, the raw materials of which, by weight, include: 12 parts of Eucommia ulmoides rubber EUG, 88 parts of natural rubber, 6 parts of zinc oxide, 1.3 parts of stearic acid, 1.3 parts of RD, 1.5 parts of 4010NA, 0.9 parts of microcrystalline wax, 25 parts of N330, 13 parts of silica (specific surface area 500 m² / g), 26 parts of paraffin oil, 8 parts of polybutylene terephthalate, 13 parts of ethylene-vinyl acetate copolymer (VA content 10%), 10 parts of potassium hexatitanate whiskers, 8 parts of polyborosiloxane (prepared from Preparation Example 2), 7 parts of zinc methacrylate, 1.4 parts of DCP, 0.95 parts of S, 0.7 parts of TMTD, 0.7 parts of DTDM, and 1.8 parts of accelerator DM.

[0049] Examples 1-5 were all prepared according to the following steps:

[0050] S1. Heat the open mill to 30-35℃, set the roll gap to 1-2mm, add Eucommia ulmoides rubber EUG and natural rubber into the open mill and plasticize for 5-10 minutes. Then, after degassing, pressing, and sheeting, cool to room temperature and let stand for 4-5 hours to obtain plasticized rubber.

[0051] S2. Heat the internal mixer to 80-90℃, add the plasticized rubber described in S1, mix for 2-5 minutes, then add the activator, co-activator, chemical antioxidant, physical antioxidant, potassium hexatitanate whiskers and zinc methacrylate in sequence, mix for 1-2 minutes, then add the reinforcing agent, ethylene-vinyl acetate copolymer, polybutylene terephthalate, polyborosiloxane and plasticizer, mix for 3-5 minutes, then discharge the rubber, compress and sheet, cool to room temperature and let stand for 3-5 hours to obtain compound rubber one;

[0052] S3. Add DCP, S, TMTD, DTDM and accelerator DM to the compound obtained in S2, mix for 2-3 minutes, then discharge the rubber, sheet it, cool it to room temperature and let it stand for 3-5 hours to obtain compound two.

[0053] S4. The compound rubber obtained in S3 is fed into a single screw extruder and extruded to obtain a waterstop tape. Then it is wound up and cooled to obtain the finished product.

[0054] Comparative Example 1:

[0055] The difference from Example 5 is that Eucommia ulmoides rubber EUG was not added; the rest of the formulation and process are completely the same as in Example 5.

[0056] The specific formulation is as follows (by weight): 88 parts natural rubber, 6 parts zinc oxide, 1.3 parts stearic acid, 1.3 parts RD, 1.5 parts 4010NA, 0.9 parts microcrystalline wax, 25 parts N330, 13 parts silica (specific surface area 500 m² / g), 26 parts paraffin oil, 8 parts polybutylene terephthalate, 13 parts ethylene-vinyl acetate copolymer (VA content 10%), 10 parts potassium hexatitanate whiskers, 8 parts polyborosiloxane (obtained from Preparation Example 2), 7 parts zinc methacrylate, 1.4 parts DCP, 0.95 parts S, 0.7 parts TMTD, 0.7 parts DTDM, and 1.8 parts accelerator DM.

[0057] Comparative Example 2:

[0058] The difference from Example 5 is that potassium hexatitanate whiskers were not added, but the rest of the formulation and process are completely the same as in Example 5.

[0059] The specific formulation is as follows (by weight): 12 parts Eucommia ulmoides rubber EUG, 88 parts natural rubber, 6 parts zinc oxide, 1.3 parts stearic acid, 1.3 parts RD, 1.5 parts 4010NA, 0.9 parts microcrystalline wax, 25 parts N330, 13 parts silica (specific surface area 500 m² / g), 26 parts paraffin oil, 8 parts polybutylene terephthalate, 13 parts ethylene-vinyl acetate copolymer (VA content 10%), 8 parts polyborosiloxane (obtained from Preparation Example 2), 7 parts zinc methacrylate, 1.4 parts DCP, 0.95 parts S, 0.7 parts TMTD, 0.7 parts DTDM, and 1.8 parts accelerator DM.

[0060] Comparative Example 3:

[0061] The difference from Example 5 is that no polyborosiloxane was added; the rest of the formulation and process are completely the same as in Example 5.

[0062] The specific formula is as follows (by weight): Eucommia ulmoides rubber EUG 12 parts, natural rubber 88 parts, zinc oxide 6 parts, stearic acid 1.3 parts, RD 1.3 parts, 4010NA 1.5 parts, microcrystalline wax 0.9 parts, N330 25 parts, silica (specific surface area 500m² / g) 13 parts, paraffin oil 26 parts, polybutylene terephthalate 8 parts, ethylene-vinyl acetate copolymer (VA content 10%) 13 parts, potassium hexatitanate whiskers 10 parts, zinc methacrylate 7 parts, DCP 1.4 parts, S 0.95 parts, TMTD 0.7 parts, DTDM 0.7 parts, and accelerator DM 1.8 parts.

[0063] Comparative Example 4:

[0064] The difference from Example 5 is that polybutylene terephthalate was not added; the rest of the formulation and process are completely the same as in Example 5.

[0065] The specific formulation is as follows (by weight): 12 parts Eucommia ulmoides rubber EUG, 88 parts natural rubber, 6 parts zinc oxide, 1.3 parts stearic acid, 1.3 parts RD, 1.5 parts 4010NA, 0.9 parts microcrystalline wax, 25 parts N330, 13 parts silica (specific surface area 500 m² / g), 26 parts paraffin oil, 13 parts ethylene-vinyl acetate copolymer (VA content 10%), 10 parts potassium hexatitanate whiskers, 8 parts polyborosiloxane (obtained from Preparation Example 2), 7 parts zinc methacrylate, 1.4 parts DCP, 0.95 parts S, 0.7 parts TMTD, 0.7 parts DTDM, and 1.8 parts accelerator DM.

[0066] Comparative Example 5:

[0067] The difference from Example 5 is that zinc methacrylate was not added; the rest of the formulation and process are completely the same as in Example 5.

[0068] The specific formulation is as follows (by weight): 12 parts Eucommia ulmoides rubber EUG, 88 parts natural rubber, 6 parts zinc oxide, 1.3 parts stearic acid, 1.3 parts RD, 1.5 parts 4010NA, 0.9 parts microcrystalline wax, 25 parts N330, 13 parts silica (specific surface area 500 m² / g), 26 parts paraffin oil, 8 parts polybutylene terephthalate, 13 parts ethylene-vinyl acetate copolymer (VA content 10%), 10 parts potassium hexatitanate whiskers, 8 parts polyborosiloxane (obtained from Preparation Example 2), 1.4 parts DCP, 0.95 parts S, 0.7 parts TMTD, 0.7 parts DTDM, and 1.8 parts accelerator DM.

[0069] Comparative Example 6:

[0070] The difference from Example 5 is that potassium hexatitanate whiskers and polyborosiloxane were not added, but the rest of the formulation and process are completely the same as in Example 5.

[0071] The specific formula is as follows (by weight): Eucommia ulmoides rubber EUG 12 parts, natural rubber 88 parts, zinc oxide 6 parts, stearic acid 1.3 parts, RD 1.3 parts, 4010NA 1.5 parts, microcrystalline wax 0.9 parts, N330 25 parts, silica (specific surface area 500m² / g) 13 parts, paraffin oil 26 parts, polybutylene terephthalate 8 parts, ethylene-vinyl acetate copolymer (VA content 10%) 13 parts, zinc methacrylate 7 parts, DCP 1.4 parts, S 0.95 parts, TMTD 0.7 parts, DTDM 0.7 parts, and accelerator DM 1.8 parts.

[0072] Comparative Example 7:

[0073] The difference from Example 5 is that polybutylene terephthalate and ethylene-vinyl acetate copolymer were not added; the rest of the formulation and process are completely the same as in Example 5.

[0074] The specific formulation is as follows (by weight): 12 parts Eucommia ulmoides rubber EUG, 88 parts natural rubber, 6 parts zinc oxide, 1.3 parts stearic acid, 1.3 parts RD, 1.5 parts 4010NA, 0.9 parts microcrystalline wax, 25 parts N330, 13 parts silica (specific surface area 500 m² / g), 26 parts paraffin oil, 10 parts potassium hexatitanate whiskers, 8 parts polyborosiloxane (obtained from Preparation Example 2), 7 parts zinc methacrylate, 1.4 parts DCP, 0.95 parts S, 0.7 parts TMTD, 0.7 parts DTDM, and 1.8 parts accelerator DM.

[0075] Comparative Example 8:

[0076] The difference from Example 5 is that zinc methacrylate and Eucommia ulmoides rubber EUG were not added; the rest of the formulation and process are completely the same as in Example 5.

[0077] The specific formulation is as follows (by weight): 88 parts natural rubber, 6 parts zinc oxide, 1.3 parts stearic acid, 1.3 parts RD, 1.5 parts 4010NA, 0.9 parts microcrystalline wax, 25 parts N330, 13 parts silica (specific surface area 500 m² / g), 26 parts paraffin oil, 8 parts polybutylene terephthalate, 13 parts ethylene-vinyl acetate copolymer (VA content 10%), 10 parts potassium hexatitanate whiskers, 8 parts polyborosiloxane (obtained from Preparation Example 2), 1.4 parts DCP, 0.95 parts S, 0.7 parts TMTD, 0.7 parts DTDM, and 1.8 parts accelerator DM.

[0078] Comparative Example 9:

[0079] The difference from Example 5 is that polybutylene terephthalate and potassium hexatitanate whiskers were not added, but the rest of the formulation and process are completely the same as in Example 5.

[0080] The specific formulation is as follows (by weight): 12 parts Eucommia ulmoides rubber EUG, 88 parts natural rubber, 6 parts zinc oxide, 1.3 parts stearic acid, 1.3 parts RD, 1.5 parts 4010NA, 0.9 parts microcrystalline wax, 25 parts N330, 13 parts silica (specific surface area 500 m² / g), 26 parts paraffin oil, 13 parts ethylene-vinyl acetate copolymer (VA content 10%), 8 parts polyborosiloxane (obtained from Preparation Example 2), 7 parts zinc methacrylate, 1.4 parts DCP, 0.95 parts S, 0.7 parts TMTD, 0.7 parts DTDM, and 1.8 parts accelerator DM.

[0081] Test Example 1: Tensile Strength and Elongation at Break

[0082] This test was conducted in accordance with the GB / T 528-2009 standard (Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber), using type 1 dumbbell-shaped specimens and a tensile speed of 500 mm / min.

[0083] Test Example 2: Self-Healing Rate

[0084] Type 1 dumbbell-shaped specimens were prepared according to GB / T 528-2009 (Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber) standard, ensuring the specimen surface was free of defects. The specimens were then placed in a standard environment (temperature 23±2℃, humidity 50±5%) for 24 hours to eliminate internal stress. A cross-shaped crack with a depth of 1 / 10 of the thickness was cut in the middle of the specimen using a blade to simulate mechanical damage. The damaged specimens were then left to rest under standard conditions without external force for 72 hours for repair. The tensile strength of the specimens before and after repair was tested using an electronic universal testing machine according to GB / T 528-2009 standard.

[0085] Self-repair rate (%) = (Tensile strength after repair / Original tensile strength) × 100%.

[0086] Test Example 3: Elastic Modulus

[0087] Principle: Based on Hooke's law, the slope of the stress-strain curve is calculated by applying a constant tensile force and measuring the deformation of the specimen.

[0088] Standard basis: GB / T 528-2009 (Tension stress-strain properties of vulcanized rubber or thermoplastic rubber), tensile speed 500 mm / min.

[0089] Steps: Use a type 1 dumbbell-shaped specimen and stretch it at a constant rate using an electronic universal testing machine. Record the stress values ​​under different strains and calculate the tangent modulus through the linear interval of the stress-strain curve.

[0090] Test Example 4: Coefficient of Friction

[0091] Principle: The coefficient of friction is calculated by measuring the ratio of the frictional force to the normal force when two contact surfaces slide relative to each other.

[0092] Standard basis: Refer to GB / T 10006-2021 "Determination of coefficient of friction of plastic films and sheets".

[0093] Procedure: Place the sample on a horizontal test platform, load a 500 g standard weight on the upper surface, drag it at a constant speed of 100 mm / min, record the average friction force during the sliding process, repeat 3 times and take the average value.

[0094] The test results of Examples 1-5 and Comparative Examples 1-9 are shown in Table 1.

[0095] Table 1. Test results of Examples 1-5 and Comparative Examples 1-9

[0096]

[0097] Compared with Example 5, Comparative Example 1, without the addition of Eucommia ulmoides rubber EUG, showed a decrease in the tensile strength of the waterstop to 16.5 MPa, an increase in elongation at break to 420%, and a decrease in self-healing rate to 57%. This indicates that the introduction of Eucommia ulmoides rubber EUG significantly improves the mechanical properties and dynamic reversible network density of the material, endows the rubber material main chain with higher flexibility and fracture energy absorption capacity, thereby significantly improving the self-healing rate of the waterstop after damage.

[0098] Compared with Example 5, Comparative Example 8 did not add zinc methacrylate and Eucommia ulmoides rubber EUG. The tensile strength of the waterstop decreased to 13.8 MPa, the elongation at break decreased to 350%, and the self-healing rate decreased to 38%. This indicates that Eucommia ulmoides rubber EUG is the core component for self-healing. Zinc methacrylate can significantly improve the tensile strength of the waterstop by optimizing the network structure and dispersing and transferring external stress.

[0099] As shown in Comparative Examples 1 and 8, Eucommia ulmoides rubber EUG forms an interpenetrating network with natural rubber through physical cross-linking in the crystalline region. It is the core component that forms the basis of the material's flexibility and self-healing. Its crystalline phase can achieve molecular chain reset through reversible transformation after damage. Combined with the boron-oxygen weak bond recombination of polyborosiloxane, it jointly ensures efficient self-healing. Zinc methacrylate improves the interfacial bonding force between natural rubber and Eucommia ulmoides rubber EUG, promotes the formation of a three-dimensional cross-linked network structure, and enhances the comprehensive performance of the waterstop by combining with other components (such as Eucommia ulmoides rubber EUG and polyborosiloxane).

[0100] The elastic modulus of the waterstop in Comparative Example 1 decreased to 5.1 MPa, and the elastic modulus of the waterstop in Comparative Example 8 decreased to 4.8 MPa, indicating that Eucommia ulmoides rubber EUG can improve the rigidity of the waterstop.

[0101] Compared with Example 5, Comparative Example 2, which did not add potassium hexatitanate whiskers, showed that the coefficient of friction of the waterstop increased to 0.653, the elastic modulus decreased to 4.1 MPa, the tensile strength decreased to 18.2 MPa, the elongation at break decreased to 500%, and the self-healing rate decreased to 85%. This indicates that potassium hexatitanate whiskers mainly improve the rigidity of the waterstop and have no significant effect on the self-healing ability.

[0102] Compared with Example 5, Comparative Example 6, which did not add the dual components of potassium hexatitanate whiskers and polyborosiloxane, showed a decrease in the tensile strength of the waterstop to 15.2 MPa, an increase in elongation at break to 380%, a decrease in self-healing rate to 65%, and a decrease in elastic modulus to 4.9 MPa. This indicates that potassium hexatitanate whiskers and polyborosiloxane synergistically enhance rigidity and strength. Potassium hexatitanate whiskers bear the stress transfer, while polyborosiloxane provides dynamic network support; neither can be omitted.

[0103] Comparative Examples 2 and 6 show that, in Comparative Example 2, without the addition of potassium hexatitanate whiskers, the elastic modulus of the waterstop decreased from 6.2 MPa in Example 5 to 4.1 MPa, indicating that potassium hexatitanate whiskers mainly enhance the material's rigidity, i.e., elastic modulus, by constructing a three-dimensional rigid framework; the tensile strength of the waterstop decreased from 23 MPa in Example 5 to 18.2 MPa, indicating that potassium hexatitanate whiskers disperse stress through a high aspect ratio structure; the tensile strength of the waterstop in Comparative Example 6 decreased from 23 MPa in Example 5 to 15.2 MPa. a. The elastic modulus decreased from 6.2 MPa to 4.9 MPa, indicating that potassium hexatitanate whiskers and polyborosiloxane synergistically support the structural strength through a "rigid skeleton (potassium hexatitanate whiskers) - dynamic network", neither of which can be omitted. The self-repair rate of the waterstop in Comparative Example 6 decreased from 95% in Example 5 to 65%, while the self-repair rate of the waterstop in Comparative Example 2 was 85%, indicating that polyborosiloxane has self-repair capability, and potassium hexatitanate whiskers help maintain the structural stability after repair by limiting deformation. The two work together to ensure the dynamic repair efficiency.

[0104] As can be seen from Comparative Examples 2 and 9, Comparative Example 9 did not add potassium hexatitanate whiskers and polybutylene terephthalate. The tensile strength of the waterstop decreased from 23 MPa in Example 5 to 14.5 MPa, and the elastic modulus decreased from 6.2 MPa to 3.1 MPa. Both were lower than the performance of Comparative Example 2. This indicates that the rigid segments of polybutylene terephthalate and the three-dimensional skeleton of potassium hexatitanate whiskers form a "rigid-rigid" synergistic support system, which together ensures the structural strength of the material.

[0105] Compared with Example 5, Comparative Example 4, which did not contain polybutylene terephthalate, showed that the tensile strength of the waterstop decreased to 17.8 MPa, the elongation at break decreased to 530%, the self-healing rate decreased to 88%, the coefficient of friction increased to 0.761, and the elastic modulus decreased to 4.4 MPa. This indicates that although polybutylene terephthalate is not the dominant self-healing component, its rigid segments significantly improve the modulus and creep resistance.

[0106] Compared to Example 5, Comparative Example 7, which did not include polybutylene terephthalate (PET) and ethylene-vinyl acetate copolymer, showed a decrease in the tensile strength of the waterstop to 16.0 MPa, a decrease in the elongation at break to 460%, a decrease in the self-healing rate to 85%, an increase in the coefficient of friction to 0.745, and a decrease in the elastic modulus to 4.6 MPa. The polar side chains of the ethylene-vinyl acetate copolymer effectively compatibilized the interface between PET and natural rubber. The absence of this component resulted in uneven dispersion of PET, leading to a deterioration in the performance of the waterstop.

[0107] The tensile strength of the waterstop in Comparative Example 4 decreased to 17.8 MPa, while the tensile strength of the waterstop in Comparative Example 7 further decreased to 16.0 MPa. This indicates that the rigid segments of polybutylene terephthalate (PET) can significantly improve the modulus and creep resistance of the material, and the absence of this component leads to a decrease in tensile strength. Although PET provides rigid support, its effect on elongation at break is relatively small, mainly manifested as a decrease in modulus. The absence of ethylene-vinyl acetate copolymer leads to a reduction in the flexible segments of the waterstop, resulting in a decrease in the overall flexibility of the material, and thus a further decrease in elongation at break.

[0108] The self-healing rate of the waterstop in Comparative Example 4 was 88%, while the self-healing rate of the waterstop in Comparative Example 7 decreased to 85%, indicating that polybutylene terephthalate is not the core component of self-healing, and therefore has little impact on the self-healing rate.

[0109] The friction coefficient of the waterstop in Comparative Example 4 was 0.761, while that in Comparative Example 7 was 0.745, indicating that polybutylene terephthalate optimizes construction performance by reducing the surface energy of the material.

[0110] In summary, the components used in this invention exert a comprehensive effect through a multi-dimensional synergistic mechanism of "rigidity-flexibility-repair-friction reduction". Potassium hexatitanate whiskers provide a lateral stiffness support structure, polyborosiloxane imparts dynamic repair properties to the material, Eucommia ulmoides rubber EUG and zinc methacrylate synergistically optimize the interfacial bonding efficiency and self-healing performance, and polybutylene terephthalate and ethylene-vinyl acetate copolymer jointly construct a balanced network structure that combines rigidity and flexibility. Thus, they jointly ensure the comprehensive performance of the waterstop in terms of mechanical strength, construction operability, damage self-healing ability, and sealing reliability.

Claims

1. A waterstop strip, characterized in that, The raw materials, by weight, include: 5-15 parts Eucommia ulmoides rubber (EUG), 85-95 parts natural rubber, 4-9 parts activator, 1-2 parts co-activator, 1-4 parts chemical antioxidant, 0.5-1.5 parts physical antioxidant, 30-50 parts reinforcing agent, 20-30 parts plasticizer, 5-10 parts potassium hexatite whiskers, 5-15 parts polyborosiloxane, 5-10 parts polybutylene terephthalate, 10-20 parts ethylene-vinyl acetate copolymer, 5-10 parts zinc methacrylate, 1-2 parts DCP, 0.8-1.5 parts S, 0.5-2 parts TMTD, 0.5-1.5 parts DTDM, and 1-2 parts accelerator DM.

2. The waterstop strip according to claim 1, characterized in that, The activator is either zinc oxide or magnesium oxide.

3. A waterstop according to claim 1, characterized in that, The VA content in the ethylene-vinyl acetate copolymer is 5%-10%.

4. A waterstop according to claim 1, characterized in that, The activator is stearic acid.

5. A waterstop according to claim 1, characterized in that, The reinforcing agent is a composition of carbon black and silica, wherein the carbon black is one of N330, N550 or N660, and the silica has a specific surface area of ​​400-500 m² / g.

6. A waterstop according to claim 1, characterized in that, The plasticizer is one of paraffin oil, naphthenic oil, or engine oil.

7. A waterstop according to claim 1, characterized in that, The chemical antioxidant is a combination of diphenylamine and phenolic antioxidants.

8. A waterstop according to claim 1, characterized in that, The physical anti-aging agent is microcrystalline wax.

9. A method for preparing a waterstop as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Heat the open mill to 30-35℃, set the roll gap to 1-2mm, add Eucommia ulmoides rubber EUG and natural rubber into the open mill and plasticize for 5-10 minutes. Then, after degassing, pressing, sheeting, cooling to room temperature and standing for 4-5 hours, the plasticized rubber is obtained. S2. Heat the internal mixer to 80-90℃, add the plasticized rubber described in S1, mix for 2-5 minutes, then add the activator, co-activator, chemical antioxidant, physical antioxidant, potassium hexatitanate whiskers and zinc methacrylate in sequence, mix for 1-2 minutes, then add the reinforcing agent, ethylene-vinyl acetate copolymer, polybutylene terephthalate, polyborosiloxane and plasticizer, mix for 3-5 minutes, then discharge the rubber, press into sheets, unsheet, cool to room temperature and let stand for 3-5 hours to obtain compound rubber one; S3. Add DCP, S, TMTD, DTDM and accelerator DM to the compound obtained in S2. Mix for 2-3 minutes, then discharge the rubber, sheet it, cool it to room temperature and let it stand for 3-5 hours to obtain compound two. S4. The compound rubber obtained in S3 is fed into a single screw extruder and extruded to obtain a waterstop tape. Then it is wound up and cooled to obtain the finished product.

10. The preparation method according to claim 9, characterized in that, The polyborosiloxane is synthesized by a condensation reaction of hydroxyl-terminated polydimethylsiloxane and boric acid, and the hydroxyl content of the hydroxyl-terminated polydimethylsiloxane is 2.5%-9.2%.

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