High-strength cold-resistant bridge tunnel waterproof and drainage board and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and particularly discloses a high-strength cold-resistant bridge and tunnel waterproof and drainage board and a preparation method thereof, and the waterproof and drainage board is prepared from the following raw materials in parts by weight through melt blending, calendaring molding and irradiation crosslinking; the raw materials comprise 35-45 parts of high-density polyethylene, 30-40 parts of a toughening component and 20-30 parts of a cold-resistant reinforced master batch with a core-shell structure; the toughening component comprises a polyolefin elastomer and an ethylene-vinyl acetate copolymer. The prepared waterproof and drainage board is excellent in comprehensive performance, high in tensile strength, excellent in low-temperature toughness and excellent in freeze-thaw cycle aging resistance. Compared with a physically blended product, the waterproof and drainage board disclosed by the invention shows a remarkable progress in a test for simulating severe working conditions, and can meet the severe requirements of high-end application scenes such as bridges and tunnels on the long-term service reliability of waterproof and drainage materials.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board and its preparation method. Background Technology

[0002] Waterproofing boards are indispensable key waterproofing components in modern tunnel engineering, and their performance directly affects the safety and durability of the tunnel structure. For conventional underground tunnels, waterproofing boards mainly bear the mechanical stress during construction and installation, as well as the subsequent pressure from the surrounding rock. However, when the application scenarios expand to the connection sections between bridges and tunnels, the entrance sections of highway tunnels, or shallow-buried tunnels with complex geological conditions in high-altitude and cold regions, waterproofing boards will face more severe environmental challenges.

[0003] These exposed or semi-exposed structures are subjected to drastic diurnal temperature variations and seasonal freeze-thaw cycles year-round. In winter, ambient temperatures can plummet to -30°C or even below -40°C, posing a severe challenge to the low-temperature brittleness of drainage boards primarily made of high-density polyethylene (HDPE). HDPE has a high glass transition temperature; at low temperatures, the movement of molecular chain segments is restricted, causing the material to transition from a ductile to a brittle state, making it highly susceptible to brittle fracture under external impact. Simultaneously, repeated thermal expansion and contraction generate cyclic stress within the material, inducing the initiation and propagation of microcracks, ultimately leading to fatigue failure, leakage in the drainage system, and jeopardizing structural safety.

[0004] To improve the toughness of polyethylene-based drainage boards, existing technologies often employ physical blending methods to add elastomers (such as EPDM rubber, POE polyolefin elastomer) or inorganic rigid particles (such as nano-SiO2) for modification. However, such technical solutions have the following inherent technical drawbacks:

[0005] 1. Poor interfacial compatibility leads to performance degradation: HDPE is a non-polar polymer, while elastomers such as EPDM and POE, as well as inorganic nanofillers, have inherent thermodynamic incompatibility with it. Through simple physical blending, the phases are only bound together by weak van der Waals forces or physical entanglement, resulting in weak interfacial bonding. Under long-term cyclic temperature stress, the phase interfaces are prone to debonding, forming stress concentration points. This not only fails to effectively transfer stress but also accelerates the fatigue failure of the material, leading to a rapid degradation of its mechanical properties.

[0006] 2. Uneven dispersion of nanofillers leads to performance degradation: Due to their large specific surface area and high surface energy, nanoparticles (such as nano-SiO2) are prone to agglomeration in polymer melts, forming large aggregates. These aggregates not only fail to provide the expected nano-reinforcement but also become sources of defects within the material, significantly reducing its impact toughness and fatigue life, making the material's performance unstable and difficult to control. Based on the above, this invention proposes a high-strength, cold-resistant bridge and tunnel drainage board and its preparation method. Summary of the Invention

[0007] To address the technical problems of existing drainage boards, such as poor component compatibility and uneven filler dispersion leading to high low-temperature brittleness and insufficient fatigue resistance, which prevent them from meeting the long-term service requirements under harsh working conditions like bridges and tunnels, this invention proposes a high-strength, cold-resistant bridge and tunnel drainage board and its preparation method.

[0008] In a first aspect, the present invention provides a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board, which adopts the following technical solution:

[0009] A high-strength, cold-resistant bridge and tunnel waterproofing and drainage board is made from the following raw materials by weight through melt blending, calendering, and irradiation crosslinking.

[0010] The raw materials include: 35-45 parts of high-density polyethylene (HDPE), 30-40 parts of toughening components, and 20-30 parts of core-shell structure cold-resistant reinforcing masterbatch;

[0011] The toughening component comprises polyolefin elastomer (POE) and ethylene-vinyl acetate copolymer (EVA).

[0012] Preferably, the mass ratio of the polyolefin elastomer to the ethylene-vinyl acetate copolymer is 1-2:1-2; POE provides excellent low-temperature toughening effect, while EVA improves the flexibility of the material and its compatibility with the HDPE matrix. The combination of the two has a synergistic effect.

[0013] Preferably, the core-shell structure cold-resistant reinforced masterbatch includes a core and a shell.

[0014] Preferably, the core is composed of functionalized modified EPDM rubber and nano-silica; the functionalized modified EPDM rubber can form chemical bonds with the surface of nano-silica, and its main chain is sensitive to radiation, which is conducive to the subsequent formation of cross-linked network; the nano-silica, as a reinforcing phase, is tightly bonded to the rubber matrix by chemical bonds, avoiding agglomeration and significantly improving the modulus and strength of the cross-linked network.

[0015] Preferably, the shell is composed of very low density polyethylene (VLDPE) and maleic anhydride-grafted polyolefin compatibilizer; VLDPE itself has excellent low-temperature toughness, and as a shell layer wrapped around the core, it has a low melting point and melts preferentially during the final co-extrusion, playing a lubricating role and physically isolating the interaction force between the cores, promoting the uniform dispersion of the core microregions; the maleic anhydride-grafted polyolefin compatibilizer enhances the interfacial bonding force between the shell and the HDPE matrix, as well as between the core and the shell.

[0016] Preferably, in the core-shell structure cold-resistant reinforcing masterbatch, the mass ratio of the core to the shell is 6-7:3-4.

[0017] Preferably, the mass ratio of functionalized modified EPDM rubber to nano-silica in the core is 6-7:1.

[0018] Preferably, the functionalized modified EPDM rubber is prepared by the following method:

[0019] a. Propyltriethoxysilane isocyanate and N-(2-hydroxyethyl)maleimide are reacted with a catalyst to undergo a polyurethane addition reaction to obtain a functional coupling agent;

[0020] b. Ethylene propylene diene monomer (EPDM) rubber and a functional coupling agent are subjected to a melt grafting reaction under the action of a free radical initiator to obtain functionalized modified EPDM rubber.

[0021] Preferably, the mass ratio of propyltriethoxysilane isocyanate, N-(2-hydroxyethyl)maleimide and catalyst in a is 10:5.5-6.5:0.01-0.02.

[0022] Preferably, the catalyst in a is dibutyltin dilaurate.

[0023] Preferably, the mass ratio of EPDM rubber, functional coupling agent and free radical initiator in b is 100:5-7:0.2-0.4.

[0024] Preferably, the free radical initiator in b is dicumyl peroxide (DCP).

[0025] Preferably, the mass ratio of very low density polyethylene to maleic anhydride grafted polyolefin compatibilizer in the shell is 8-10:1.

[0026] Preferably, the core-shell structure cold-resistant reinforced masterbatch is prepared by the following method:

[0027] (1) Functionalized modified EPDM rubber and nano silica are premixed in a high-speed mixer, and then melt-blended and extruded by a twin-screw extruder to obtain core granules;

[0028] (2) Mix very low density polyethylene and maleic anhydride grafted polyolefin compatibilizer evenly to obtain shell material;

[0029] (3) The core granules are used as the main feed and the shell material is used as the side feed. The core granules are melt-coated and extruded through a co-rotating twin-screw extruder. After water cooling and pelletizing, the core-shell structure cold-resistant reinforced masterbatch is obtained.

[0030] Preferably, the premixing parameters in (1) are as follows: temperature is 60-80℃, rotation speed is 800-1000rpm, and time is 8-10min.

[0031] Preferably, the temperature of each zone of the twin-screw extruder in (1) is set as follows: Zone 1 160-170℃, Zone 2 175-185℃, Zone 3 185-195℃, Zone 4 190-200℃, Zone 5 185-195℃, and the die head temperature is 180-190℃; the screw speed is 300-400rpm.

[0032] Preferably, the mixing parameters in (2) are as follows: mix at room temperature for 20-30 minutes.

[0033] Preferably, the temperature of each zone of the co-rotating twin-screw extruder in (3) is set as follows: Zone 1 140-150℃, Zone 2 155-165℃, Zone 3 165-175℃, Zone 4 170-180℃, Zone 5 165-175℃, and the die head temperature is 160-170℃; the screw speed is 200-300 rpm.

[0034] Secondly, the present invention provides a method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board, which adopts the following technical solution:

[0035] A method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board includes the following steps:

[0036] S1. The core-shell structure cold-resistant reinforced masterbatch is mixed with high-density polyethylene and toughening components at high speed to obtain a mixture.

[0037] S2. The mixture is melt-extruded through a sheet extruder and calendered to obtain a semi-finished waterproof and drainage board. During this process, the low-melting-point shell of the core-shell structure cold-resistant reinforcing masterbatch will melt first, enveloping the core and achieving stable and uniform dispersion in the HDPE matrix melt.

[0038] S3. Electron beam irradiation treatment is performed on the semi-finished waterproof and drainage board to obtain a high-strength cold-resistant bridge and tunnel waterproof and drainage board. This step utilizes the sensitivity of the EPDM main chain to high-energy radiation to selectively perform deep cross-linking on the uniformly dispersed core micro-regions, transforming them from a thermoplastic state into a highly cross-linked elastomer network, while having little impact on the HDPE-based thermoplastic matrix. Finally, a stable semi-interpenetrating network structure is constructed in situ inside the material.

[0039] The microstructure of the drainage board of the present invention is as follows: in the thermoplastic matrix phase composed of HDPE and toughening components, highly cross-linked elastomer microregions derived from the core transformation of the core-shell structure cold-resistant reinforcing masterbatch are uniformly dispersed, and the two together form a stable semi-interpenetrating network structure.

[0040] Preferably, the mixing parameters in S1 are as follows: in a high-speed mixer, the temperature is set to 80-100℃, the rotation speed is 600-800rpm, and the mixing time is 10-15min.

[0041] Preferably, the sheet extruder in S2 is set with the following temperatures: feeding section 175-185℃, melting section 205-215℃, metering section 215-225℃, and die head 210-220℃.

[0042] Preferably, the calendering process in S2 specifically refers to: the molten sheet material extruded from the die head entering a three-roll calender for calendering and shaping, wherein the roller temperature of the three-roll calender is set to 140-160℃ and the calendering linear speed is 2-5m / min.

[0043] Preferably, the electron beam irradiation treatment in S3 specifically refers to: irradiation in an air environment at room temperature by a high-energy electron beam, with an accelerating voltage of 1.5-2.5 MeV and a total absorbed dose of 20-40 kGy.

[0044] In summary, the present invention has the following beneficial effects:

[0045] This invention synthesizes a functional coupling agent containing triethoxysilane and maleimide groups via a polyurethane addition reaction. In a subsequent melt grafting reaction, the maleimide groups are grafted onto the nonpolar EPDM macromolecular backbone via free radical initiation, introducing the triethoxysilane groups into the EPDM segments. Upon thermal shearing during blending with nano-silica, the triethoxysilane groups hydrolyze to generate highly reactive silanol groups, which undergo dehydration condensation with the hydroxyl groups on the surface of nano-silica to form stable "Si-O-Si" covalent bonds. This invention employs chemical bonding to thoroughly suppress the aggregation of nano-silica, achieving uniform dispersion at the nanoscale and constructing a robust filler-rubber interface. This allows external stress to be efficiently transferred from the flexible rubber matrix to the high-strength nanofiller, achieving a synergistic nano-reinforcement effect.

[0046] This invention solves the problem of poor compatibility in multi-component systems by pre-preparing core-shell structured cold-resistant reinforcing masterbatches. The shell structure plays a crucial role in dispersion and interface improvement during subsequent processing, ensuring the uniform dispersion of functional core microregions within the HDPE matrix. Through final electron beam irradiation treatment, the uniformly dispersed EPDM core microregions are selectively and deeply crosslinked, transforming them from a thermoplastic state into a highly crosslinked elastomer network with minimal impact on the HDPE-based thermoplastic matrix. In the resulting semi-interpenetrating network structure, the continuous thermoplastic matrix phases (HDPE, POE, EVA) impart excellent low-temperature toughness and processing properties; while the dispersed crosslinked elastomer microregions (the crosslinked core) act as reinforcing phases and stress absorption centers, significantly improving the material's tensile strength, creep resistance, and thermal dimensional stability, fundamentally preventing performance degradation due to phase separation or aging during long-term use.

[0047] The drainage board produced by this invention exhibits excellent comprehensive performance, possessing high tensile strength, outstanding low-temperature toughness, and superior resistance to freeze-thaw cycles. Compared to products using simple physical blending, the drainage board of this invention achieves a 100% pass rate in the -50℃ low-temperature embrittlement test and withstands over 50 bending cycles at -40℃ without breakage. After 100 freeze-thaw cycles, its tensile strength and elongation at break retain over 90%, meeting the stringent requirements for long-term reliability of drainage materials in high-end applications such as bridges and tunnels. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to the embodiments.

[0049] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0050] The key raw materials used in this invention are sourced from the following sources:

[0051] High-density polyethylene: Brand Formosa Plastics, grade 8050, purchased from Shanghai Yichu Petrochemical Co., Ltd.

[0052] Polyolefin elastomer: Brand: Dow (Thailand), Grade 9500, purchased from Shanghai Caihong Plastics Co., Ltd.

[0053] Ethylene-vinyl acetate copolymer: Brand Elvax, grade 670, purchased from Shanghai Bangsu New Materials Co., Ltd.;

[0054] Propyltriethoxysilane isocyanate: Brand Xinghengye, CAS No. 24801-88-5, purchased from Hubei Xinghengye Technology Co., Ltd.

[0055] N-(2-hydroxyethyl)maleimide: Brand Xingyan, CAS No. 1585-90-6, purchased from Hubei Xingyan New Material Technology Co., Ltd.;

[0056] Dibutyltin dilaurate: Brand: Yukang Chemical, CAS No. 77-58-7, purchased from Shandong Yukang Chemical Co., Ltd.

[0057] EPDM rubber: Brand: Dow Chemical, USA, grade 3640, purchased from Shanghai Tingyuan Plastics Technology Co., Ltd.

[0058] Dicumyl peroxide: CAS No. 80-43-3, Product No. 329541-500G, purchased from MeRck;

[0059] Nano silica: 20nm particle size, model JC-SP20, purchased from Shenzhen Jingcai Chemical Co., Ltd.

[0060] Very low density polyethylene: grade LL8004V, purchased from Dongguan Hongkuo Plastics Co., Ltd.;

[0061] Maleic anhydride grafted polyolefin compatibilizer: Brand: Dow Chemical (USA), Grade: N416, purchased from Dongguan Nabaichuan Plastics Co., Ltd.

[0062] Preparation Examples 1-3 and Comparative Preparation Example 1-2 provide functionalized modified EPDM rubber.

[0063] Preparation Example 1

[0064] Functionalized modified EPDM rubber is prepared by the following method:

[0065] a. The mass ratio of propyltriethoxysilane isocyanate, N-(2-hydroxyethyl)maleimide and dibutyltin dilaurate is controlled at 10:5.5:0.01. The propyltriethoxysilane isocyanate, N-(2-hydroxyethyl)maleimide and dibutyltin dilaurate are heated to 65°C under nitrogen protection to carry out a polyurethane addition reaction. The reaction is carried out for 5 hours until the reaction is completed, and the functional coupling agent is obtained.

[0066] b. Controlling the mass ratio of EPDM rubber, functional coupling agent, and dicumyl peroxide to 100:5:0.2, the EPDM rubber, functional coupling agent, and dicumyl peroxide are added to a high-speed mixer and premixed at 75°C and 800 rpm for 12 min. The mixture is then added to a twin-screw extruder for melt grafting reaction. The temperatures of each zone of the extruder are set as follows: Zone 1 155°C, Zone 2 170°C, Zone 3 180°C, Zone 4 185°C, Zone 5 180°C, Die head temperature 175°C, and screw speed 320 rpm. The extrudate is water-cooled and pelletized, then vacuum dried at 60°C to constant weight to obtain functionalized modified EPDM rubber.

[0067] Preparation Example 2

[0068] Functionalized modified EPDM rubber is prepared by the following method:

[0069] a. The mass ratio of propyltriethoxysilane isocyanate, N-(2-hydroxyethyl)maleimide and dibutyltin dilaurate is controlled at 10:6:0.015. The propyltriethoxysilane isocyanate, N-(2-hydroxyethyl)maleimide and dibutyltin dilaurate are heated to 70°C under nitrogen protection to carry out a polyurethane addition reaction. The reaction is carried out for 4 hours until the reaction is completed, and the functional coupling agent is obtained.

[0070] b. Controlling the mass ratio of EPDM rubber, functional coupling agent, and dicumyl peroxide to 100:6:0.3, the EPDM rubber, functional coupling agent, and dicumyl peroxide are added to a high-speed mixer and premixed at 80°C and 900 rpm for 10 min. The mixture is then added to a twin-screw extruder for melt grafting reaction. The temperatures of each zone of the extruder are set as follows: Zone 1 160°C, Zone 2 175°C, Zone 3 185°C, Zone 4 190°C, Zone 5 185°C, Die head temperature 180°C, and screw speed 300 rpm. The extrudate is water-cooled and pelletized, then vacuum dried at 70°C to constant weight to obtain functionalized modified EPDM rubber.

[0071] Preparation Example 3

[0072] Functionalized modified EPDM rubber is prepared by the following method:

[0073] a. The mass ratio of propyltriethoxysilane isocyanate, N-(2-hydroxyethyl)maleimide and dibutyltin dilaurate is controlled at 10:6.5:0.02. The propyltriethoxysilane isocyanate, N-(2-hydroxyethyl)maleimide and dibutyltin dilaurate are heated to 75°C under nitrogen protection to carry out a polyurethane addition reaction. The reaction is carried out for 3 hours until the reaction is completed, and the functional coupling agent is obtained.

[0074] b. Controlling the mass ratio of EPDM rubber, functional coupling agent, and dicumyl peroxide to 100:7:0.4, the EPDM rubber, functional coupling agent, and dicumyl peroxide are added to a high-speed mixer and premixed at 1000 rpm for 8 minutes at 85°C. The mixture is then added to a twin-screw extruder for melt grafting reaction. The temperatures of each zone of the extruder are set as follows: Zone 1 165°C, Zone 2 180°C, Zone 3 190°C, Zone 4 195°C, Zone 5 190°C, Die head temperature 185°C, and screw speed 280 rpm. The extrudate is water-cooled and pelletized, then vacuum dried at 80°C to constant weight to obtain functionalized modified EPDM rubber.

[0075] Comparative Preparation Example 1

[0076] Functionalized modified EPDM rubber is prepared by the following method:

[0077] The mass ratio of EPDM rubber, propyltriethoxysilane isocyanate, and dicumyl peroxide was controlled at 100:5:0.2. EPDM rubber, propyltriethoxysilane isocyanate, and dicumyl peroxide were added to a high-speed mixer and premixed at 75°C and 800 rpm for 12 min. The mixture was then fed into a twin-screw extruder for melt grafting reaction. The temperatures of each zone of the extruder were set as follows: zone 1 155°C, zone 2 170°C, zone 3 180°C, zone 4 185°C, zone 5 180°C, die head temperature 175°C, and screw speed 320 rpm. The extrudate was water-cooled, pelletized, and vacuum-dried at 60°C to constant weight to obtain functionalized modified EPDM rubber.

[0078] Comparative Preparation Example 2

[0079] Functionalized modified EPDM rubber is prepared by the following method:

[0080] The mass ratio of EPDM rubber, N-(2-hydroxyethyl)maleimide, and dicumyl peroxide was controlled at 100:5:0.2. EPDM rubber, N-(2-hydroxyethyl)maleimide, and dicumyl peroxide were added to a high-speed mixer and premixed at 800 rpm for 12 min at 75°C. The mixture was then fed into a twin-screw extruder for melt grafting reaction. The temperatures of each zone of the extruder were set as follows: zone 1 155°C, zone 2 170°C, zone 3 180°C, zone 4 185°C, zone 5 180°C, die head temperature 175°C, and screw speed 320 rpm. The extrudate was water-cooled, pelletized, and vacuum-dried at 60°C to constant weight to obtain functionalized modified EPDM rubber.

[0081] Preparation Examples 4-6 and Comparative Preparation Examples 3-4 provide core-shell structured cold-resistant reinforced masterbatches, while Comparative Preparation Example 5 provides a cold-resistant reinforced masterbatch.

[0082] Preparation Example 4

[0083] Core-shell structured cold-resistant reinforced masterbatch is prepared by the following method:

[0084] (1) The mass ratio of functionalized modified EPDM rubber and nano silica was controlled to be 6:1. The functionalized modified EPDM rubber and nano silica in Preparation Example 1 were added together into a high-speed mixer. The temperature was controlled at 60℃ and the speed was controlled at 800 rpm. The mixture was premixed for 10 min and then melt-blended and extruded into granules by a twin-screw extruder. The temperature of each zone of the twin-screw extruder was set as follows: Zone 1 160℃, Zone 2 175℃, Zone 3 185℃, Zone 4 190℃, Zone 5 185℃, and the die head temperature was 180℃. The screw speed was 400 rpm. The extrudate was water-cooled and pelletized, and then vacuum dried at 60℃ to constant weight to obtain core granules.

[0085] (2) Control the mass ratio of ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer to 8:1. Mix ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer at 300 rpm for 30 min at room temperature until they are mixed evenly to obtain shell material.

[0086] (3) The mass ratio of core to shell is controlled at 6:3. Core granules are used as the main feed and shell material is used as the side feed. The core granules are melt-coated and extruded through a co-rotating twin-screw extruder. The temperature of each zone of the co-rotating twin-screw extruder is set as follows: Zone 1 140℃, Zone 2 155℃, Zone 3 165℃, Zone 4 170℃, Zone 5 165℃, and the die head temperature is 160℃. The screw speed is 300 rpm. The extrudate is water-cooled and pelletized, and then vacuum dried at 60℃ to constant weight to obtain core-shell structure cold-resistant reinforced masterbatch.

[0087] Preparation Example 5

[0088] Core-shell structured cold-resistant reinforced masterbatch is prepared by the following method:

[0089] (1) The mass ratio of functionalized modified EPDM rubber and nano silica was controlled to be 6.5:1. The functionalized modified EPDM rubber and nano silica in Preparation Example 2 were added together into a high-speed mixer. The temperature was controlled to be 70℃ and the speed was 900rpm. The mixture was premixed for 9min and then melt-blended and extruded into granules by a twin-screw extruder. The temperature of each zone of the twin-screw extruder was set as follows: Zone 1 165℃, Zone 2 180℃, Zone 3 190℃, Zone 4 195℃, Zone 5 190℃, and the die head temperature was 185℃. The screw speed was 350rpm. The extrudate was water-cooled and pelletized, and then vacuum dried at 70℃ to constant weight to obtain core granules.

[0090] (2) Control the mass ratio of ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer to 9:1. Mix ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer at 400 rpm for 25 min at room temperature until they are mixed evenly to obtain shell material.

[0091] (3) The mass ratio of core to shell is controlled at 6.5:3.5. Core granules are used as the main feed and shell material is used as the side feed. The core granules are melt-coated and extruded through a co-rotating twin-screw extruder. The temperature of each zone of the co-rotating twin-screw extruder is set as follows: Zone 1 145℃, Zone 2 160℃, Zone 3 170℃, Zone 4 175℃, Zone 5 170℃, and the die head temperature is 165℃. The screw speed is 250 rpm. The extrudate is water-cooled and pelletized, and then vacuum dried at 70℃ to constant weight to obtain core-shell structure cold-resistant reinforced masterbatch.

[0092] Preparation Example 6

[0093] Core-shell structured cold-resistant reinforced masterbatch is prepared by the following method:

[0094] (1) The mass ratio of functionalized modified EPDM rubber and nano silica was controlled to be 7:1. The functionalized modified EPDM rubber and nano silica in Preparation Example 3 were added together into a high-speed mixer. The temperature was controlled to be 80℃ and the speed was 1000rpm. The mixture was premixed for 8min and then melt-blended and extruded into granules by a twin-screw extruder. The temperature of each zone of the twin-screw extruder was set as follows: Zone 1 170℃, Zone 2 185℃, Zone 3 195℃, Zone 4 200℃, Zone 5 195℃, and the die head temperature was 190℃. The screw speed was 300rpm. The extrudate was water-cooled and pelletized, and then vacuum dried at 80℃ to constant weight to obtain core granules.

[0095] (2) Control the mass ratio of ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer to 10:1. Mix ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer at 500 rpm for 20 min at room temperature until they are mixed evenly to obtain shell material.

[0096] (3) The mass ratio of core to shell is controlled at 7:4. Core granules are used as the main feed and shell material is used as the side feed. The core granules are melt-coated and extruded through a co-rotating twin-screw extruder. The temperature of each zone of the co-rotating twin-screw extruder is set as follows: Zone 1 150℃, Zone 2 165℃, Zone 3 175℃, Zone 4 180℃, Zone 5 175℃, and the die head temperature is 170℃. The screw speed is 200 rpm. The extrudate is water-cooled and pelletized, and then vacuum dried at 80℃ to constant weight to obtain a core-shell structure cold-resistant reinforced masterbatch.

[0097] Comparative preparation example 3

[0098] Core-shell structured cold-resistant reinforced masterbatch is prepared by the following method:

[0099] (1) The mass ratio of functionalized modified EPDM rubber and nano silica was controlled to be 6:1. The functionalized modified EPDM rubber and nano silica from Comparative Preparation Example 1 were added together to a high-speed mixer. The temperature was controlled at 60°C and the speed was controlled at 800 rpm. The mixture was premixed for 10 min and then melt-blended and extruded into granules by a twin-screw extruder. The temperature of each zone of the twin-screw extruder was set as follows: Zone 1 160°C, Zone 2 175°C, Zone 3 185°C, Zone 4 190°C, Zone 5 185°C, and the die head temperature was 180°C. The screw speed was 400 rpm. The extrudate was water-cooled and pelletized, and then vacuum-dried at 60°C to constant weight to obtain core granules.

[0100] (2) Control the mass ratio of ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer to 8:1. Mix ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer at 300 rpm for 30 min at room temperature until they are mixed evenly to obtain shell material.

[0101] (3) The mass ratio of core to shell is controlled at 6:3. Core granules are used as the main feed and shell material is used as the side feed. The core granules are melt-coated and extruded through a co-rotating twin-screw extruder. The temperature of each zone of the co-rotating twin-screw extruder is set as follows: Zone 1 140℃, Zone 2 155℃, Zone 3 165℃, Zone 4 170℃, Zone 5 165℃, and the die head temperature is 160℃. The screw speed is 300 rpm. The extrudate is water-cooled and pelletized, and then vacuum dried at 60℃ to constant weight to obtain core-shell structure cold-resistant reinforced masterbatch.

[0102] Comparative preparation example 4

[0103] Core-shell structured cold-resistant reinforced masterbatch is prepared by the following method:

[0104] (1) The mass ratio of functionalized modified EPDM rubber and nano silica was controlled to be 6:1. The functionalized modified EPDM rubber and nano silica from Comparative Preparation Example 2 were added together to a high-speed mixer. The temperature was controlled at 60°C and the speed was controlled at 800 rpm. The mixture was premixed for 10 min and then melt-blended and extruded into granules by a twin-screw extruder. The temperature of each zone of the twin-screw extruder was set as follows: Zone 1 160°C, Zone 2 175°C, Zone 3 185°C, Zone 4 190°C, Zone 5 185°C, and the die head temperature was 180°C. The screw speed was 400 rpm. The extrudate was water-cooled and pelletized, and then vacuum-dried at 60°C to constant weight to obtain core granules.

[0105] (2) Control the mass ratio of ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer to 8:1. Mix ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer at 300 rpm for 30 min at room temperature until they are mixed evenly to obtain shell material.

[0106] (3) The mass ratio of core to shell is controlled at 6:3. Core granules are used as the main feed and shell material is used as the side feed. The core granules are melt-coated and extruded through a co-rotating twin-screw extruder. The temperature of each zone of the co-rotating twin-screw extruder is set as follows: Zone 1 140℃, Zone 2 155℃, Zone 3 165℃, Zone 4 170℃, Zone 5 165℃, and the die head temperature is 160℃. The screw speed is 300 rpm. The extrudate is water-cooled and pelletized, and then vacuum dried at 60℃ to constant weight to obtain core-shell structure cold-resistant reinforced masterbatch.

[0107] Comparative preparation example 5

[0108] Cold-resistant reinforcing masterbatch is prepared by the following method:

[0109] (1) The mass ratio of functionalized modified EPDM rubber and nano silica was controlled to be 6:1. The functionalized modified EPDM rubber and nano silica in Preparation Example 1 were added together into a high-speed mixer. The temperature was controlled at 60℃ and the speed was controlled at 800 rpm. The mixture was premixed for 10 min and then melt-blended and extruded into granules by a twin-screw extruder. The temperature of each zone of the twin-screw extruder was set as follows: Zone 1 160℃, Zone 2 175℃, Zone 3 185℃, Zone 4 190℃, Zone 5 185℃, and the die head temperature was 180℃. The screw speed was 400 rpm. The extrudate was water-cooled and pelletized, and then vacuum dried at 60℃ to constant weight to obtain core granules.

[0110] (2) Control the mass ratio of ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer to 8:1. Mix ultra-low density polyethylene and maleic anhydride grafted polyolefin compatibilizer at 300 rpm for 30 min at room temperature until they are mixed evenly to obtain shell material.

[0111] (3) The mass ratio of core to shell is controlled at 6:3. The core granules and shell material are added together to a high-speed mixer. The temperature is controlled at 60℃ and the speed is 800rpm. The mixture is premixed for 10min and then melt-blended and extruded into granules by a twin-screw extruder. The temperature of each zone of the twin-screw extruder is set as follows: Zone 1 140℃, Zone 2 155℃, Zone 3 165℃, Zone 4 170℃, Zone 5 165℃, and the die head temperature is 160℃. The screw speed is 300rpm. The extrudate is water-cooled and pelletized, and then vacuum-dried at 60℃ to constant weight to obtain cold-resistant reinforced masterbatch.

[0112] Examples 1-3 provide a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board and its preparation method.

[0113] Example 1

[0114] A high-strength, cold-resistant bridge and tunnel waterproofing board comprises the following raw materials in parts by weight: 35 parts high-density polyethylene, 30 parts toughening components, and 20 parts core-shell structure cold-resistant reinforcing masterbatch;

[0115] The toughening component comprises a polyolefin elastomer and an ethylene-vinyl acetate copolymer in a mass ratio of 1:2.

[0116] The core-shell structure cold-resistant reinforced masterbatch was prepared by Example 4.

[0117] A method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board includes the following steps:

[0118] S1. Add the core-shell structure cold-resistant reinforced masterbatch, high-density polyethylene, and toughening components together into a high-speed mixer. Set the temperature to 80℃ and the rotation speed to 600rpm. Mix for 15 minutes to obtain the mixture.

[0119] S2. The mixture is melted and extruded through a sheet extruder. The sheet extruder is set with the following temperatures: feeding section 175℃, melting section 205℃, metering section 215℃, and die head 210℃. Then, it is calendered through a three-roll calender with the roller temperature set at 140℃ and the calendering speed at 5m / min to obtain a semi-finished waterproof board.

[0120] S3. The semi-finished product is placed in an electron beam irradiation device and irradiated with a high-energy electron beam in an air environment at room temperature. The accelerating voltage is 1.5 MeV and the total absorbed dose is 20 kGy to obtain a high-strength cold-resistant bridge and tunnel waterproofing board.

[0121] Example 2

[0122] A high-strength, cold-resistant bridge and tunnel waterproofing board comprises the following raw materials in parts by weight: 40 parts of high-density polyethylene, 35 parts of toughening components, and 25 parts of core-shell structure cold-resistant reinforcing masterbatch.

[0123] The toughening component comprises a polyolefin elastomer and an ethylene-vinyl acetate copolymer in a mass ratio of 1:1.

[0124] The core-shell structure cold-resistant reinforced masterbatch was prepared by Example 5.

[0125] A method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board includes the following steps:

[0126] S1. Add the core-shell structure cold-resistant reinforced masterbatch, high-density polyethylene, and toughening components together into a high-speed mixer. Set the temperature to 90℃ and the rotation speed to 700rpm. Mix for 12 minutes to obtain the mixture.

[0127] S2. The mixture is melted and extruded through a sheet extruder. The sheet extruder is set with the following temperatures: feeding section 180℃, melting section 210℃, metering section 220℃, and die head 215℃. Then, it is calendered through a three-roll calender with the roller temperature set at 150℃ and the calendering speed at 3.5m / min to obtain a semi-finished waterproof and drainage board.

[0128] S3. Place the semi-finished product in an electron beam irradiation device and irradiate it with a high-energy electron beam in an air environment at room temperature. The accelerating voltage is 2MeV and the total absorbed dose is 30kGy to obtain a high-strength cold-resistant bridge and tunnel waterproofing board.

[0129] Example 3

[0130] A high-strength, cold-resistant bridge and tunnel waterproofing board comprises the following raw materials in parts by weight: 45 parts high-density polyethylene, 40 parts toughening components, and 30 parts core-shell structure cold-resistant reinforcing masterbatch;

[0131] The toughening component comprises a polyolefin elastomer and an ethylene-vinyl acetate copolymer in a mass ratio of 2:1.

[0132] The core-shell structure cold-resistant reinforced masterbatch was prepared by Example 6.

[0133] A method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board includes the following steps:

[0134] S1. Add the core-shell structure cold-resistant reinforced masterbatch, high-density polyethylene, and toughening components together into a high-speed mixer. Set the temperature to 100℃ and the rotation speed to 800rpm. Mix for 10 minutes to obtain the mixture.

[0135] S2. The mixture is melted and extruded through a sheet extruder. The sheet extruder is set with the following temperatures: feeding section 185℃, melting section 215℃, metering section 225℃, and die head 220℃. Then, it is calendered through a three-roll calender with the roller temperature set at 160℃ and the calendering speed at 2m / min to obtain a semi-finished waterproof board.

[0136] S3. The semi-finished product is placed in an electron beam irradiation device and irradiated with a high-energy electron beam in an air environment at room temperature. The accelerating voltage is 2.5 MeV and the total absorbed dose is 40 kGy, resulting in a high-strength, cold-resistant bridge and tunnel waterproofing board.

[0137] To verify the comprehensive performance of the high-strength, cold-resistant bridge and tunnel waterproofing and drainage boards prepared in Examples 1-3 of this invention, comparative examples 1-6 were set up, wherein:

[0138] Comparative Example 1

[0139] Comparative Example 1 is the same as Example 1, except that the core-shell structure cold-resistant reinforcing masterbatch was prepared from Comparative Preparation Example 3. Details are as follows:

[0140] A high-strength, cold-resistant bridge and tunnel waterproofing board comprises the following raw materials in parts by weight: 35 parts high-density polyethylene, 30 parts toughening components, and 20 parts core-shell structure cold-resistant reinforcing masterbatch;

[0141] The toughening component comprises a polyolefin elastomer and an ethylene-vinyl acetate copolymer in a mass ratio of 1:2.

[0142] The core-shell structure cold-resistant reinforced masterbatch was prepared by comparative preparation example 3.

[0143] A method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board includes the following steps:

[0144] S1. Add the core-shell structure cold-resistant reinforced masterbatch, high-density polyethylene, and toughening components together into a high-speed mixer. Set the temperature to 80℃ and the rotation speed to 600rpm. Mix for 15 minutes to obtain the mixture.

[0145] S2. The mixture is melted and extruded through a sheet extruder. The sheet extruder is set with the following temperatures: feeding section 175℃, melting section 205℃, metering section 215℃, and die head 210℃. Then, it is calendered through a three-roll calender with the roller temperature set at 140℃ and the calendering speed at 5m / min to obtain a semi-finished waterproof board.

[0146] S3. The semi-finished product is placed in an electron beam irradiation device and irradiated with a high-energy electron beam in an air environment at room temperature. The accelerating voltage is 1.5 MeV and the total absorbed dose is 20 kGy to obtain a high-strength cold-resistant bridge and tunnel waterproofing board.

[0147] Comparative Example 2

[0148] Comparative Example 2 is the same as Example 1, except that the core-shell structure cold-resistant reinforcing masterbatch was prepared from Comparative Preparation Example 4. Details are as follows:

[0149] A high-strength, cold-resistant bridge and tunnel waterproofing board comprises the following raw materials in parts by weight: 35 parts high-density polyethylene, 30 parts toughening components, and 20 parts core-shell structure cold-resistant reinforcing masterbatch;

[0150] The toughening component comprises a polyolefin elastomer and an ethylene-vinyl acetate copolymer in a mass ratio of 1:2.

[0151] The core-shell structure cold-resistant reinforced masterbatch was prepared by comparative preparation example 4.

[0152] A method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board includes the following steps:

[0153] S1. Add the core-shell structure cold-resistant reinforced masterbatch, high-density polyethylene, and toughening components together into a high-speed mixer. Set the temperature to 80℃ and the rotation speed to 600rpm. Mix for 15 minutes to obtain the mixture.

[0154] S2. The mixture is melted and extruded through a sheet extruder. The sheet extruder is set with the following temperatures: feeding section 175℃, melting section 205℃, metering section 215℃, and die head 210℃. Then, it is calendered through a three-roll calender with the roller temperature set at 140℃ and the calendering speed at 5m / min to obtain a semi-finished waterproof board.

[0155] S3. The semi-finished product is placed in an electron beam irradiation device and irradiated with a high-energy electron beam in an air environment at room temperature. The accelerating voltage is 1.5 MeV and the total absorbed dose is 20 kGy to obtain a high-strength cold-resistant bridge and tunnel waterproofing board.

[0156] Comparative Example 3

[0157] Comparative Example 3 is the same as Example 1, except that the core-shell structure cold-resistant reinforcing masterbatch is replaced with the cold-resistant reinforcing masterbatch from Comparative Preparation Example 5. Details are as follows:

[0158] A high-strength, cold-resistant bridge and tunnel waterproofing board comprises the following raw materials in parts by weight: 35 parts high-density polyethylene, 30 parts toughening components, and 20 parts cold-resistant reinforcing masterbatch;

[0159] The toughening component comprises a polyolefin elastomer and an ethylene-vinyl acetate copolymer in a mass ratio of 1:2.

[0160] The cold-resistant enhanced masterbatch was prepared from Comparative Preparation Example 5.

[0161] A method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board includes the following steps:

[0162] S1. Add the cold-resistant reinforced masterbatch, high-density polyethylene, and toughening components together into a high-speed mixer. Set the temperature to 80℃ and the speed to 600rpm. Mix for 15 minutes to obtain the mixture.

[0163] S2. The mixture is melted and extruded through a sheet extruder. The sheet extruder is set with the following temperatures: feeding section 175℃, melting section 205℃, metering section 215℃, and die head 210℃. Then, it is calendered through a three-roll calender with the roller temperature set at 140℃ and the calendering speed at 5m / min to obtain a semi-finished waterproof board.

[0164] S3. The semi-finished product is placed in an electron beam irradiation device and irradiated with a high-energy electron beam in an air environment at room temperature. The accelerating voltage is 1.5 MeV and the total absorbed dose is 20 kGy to obtain a high-strength cold-resistant bridge and tunnel waterproofing board.

[0165] Comparative Example 4

[0166] Comparative Example 4 is the same as Example 1, except that the toughening component is a polyolefin elastomer. Details are as follows:

[0167] A high-strength, cold-resistant bridge and tunnel waterproofing board comprises the following raw materials in parts by weight: 35 parts high-density polyethylene, 30 parts toughening components, and 20 parts core-shell structure cold-resistant reinforcing masterbatch;

[0168] The toughening component is a polyolefin elastomer;

[0169] The core-shell structure cold-resistant reinforced masterbatch was prepared by Example 4.

[0170] A method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board includes the following steps:

[0171] S1. Add the core-shell structure cold-resistant reinforced masterbatch, high-density polyethylene, and toughening components together into a high-speed mixer. Set the temperature to 80℃ and the rotation speed to 600rpm. Mix for 15 minutes to obtain the mixture.

[0172] S2. The mixture is melted and extruded through a sheet extruder. The sheet extruder is set with the following temperatures: feeding section 175℃, melting section 205℃, metering section 215℃, and die head 210℃. Then, it is calendered through a three-roll calender with the roller temperature set at 140℃ and the calendering speed at 5m / min to obtain a semi-finished waterproof board.

[0173] S3. The semi-finished product is placed in an electron beam irradiation device and irradiated with a high-energy electron beam in an air environment at room temperature. The accelerating voltage is 1.5 MeV and the total absorbed dose is 20 kGy to obtain a high-strength cold-resistant bridge and tunnel waterproofing board.

[0174] Comparative Example 5

[0175] Comparative Example 5 is the same as Example 1, except that the toughening component is an ethylene-vinyl acetate copolymer. Details are as follows:

[0176] A high-strength, cold-resistant bridge and tunnel waterproofing board comprises the following raw materials in parts by weight: 35 parts high-density polyethylene, 30 parts toughening components, and 20 parts core-shell structure cold-resistant reinforcing masterbatch;

[0177] The toughening component is an ethylene-vinyl acetate copolymer;

[0178] The core-shell structure cold-resistant reinforced masterbatch was prepared by Example 4.

[0179] A method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board includes the following steps:

[0180] S1. Add the core-shell structure cold-resistant reinforced masterbatch, high-density polyethylene, and toughening components together into a high-speed mixer. Set the temperature to 80℃ and the rotation speed to 600rpm. Mix for 15 minutes to obtain the mixture.

[0181] S2. The mixture is melted and extruded through a sheet extruder. The sheet extruder is set with the following temperatures: feeding section 175℃, melting section 205℃, metering section 215℃, and die head 210℃. Then, it is calendered through a three-roll calender with the roller temperature set at 140℃ and the calendering speed at 5m / min to obtain a semi-finished waterproof board.

[0182] S3. The semi-finished product is placed in an electron beam irradiation device and irradiated with a high-energy electron beam in an air environment at room temperature. The accelerating voltage is 1.5 MeV and the total absorbed dose is 20 kGy to obtain a high-strength cold-resistant bridge and tunnel waterproofing board.

[0183] Comparative Example 6

[0184] Comparative Example 6 is the same as Example 1, except that the electron beam irradiation treatment in step S3 is omitted. Specifically:

[0185] A high-strength, cold-resistant bridge and tunnel waterproofing board comprises the following raw materials in parts by weight: 35 parts high-density polyethylene, 30 parts toughening components, and 20 parts core-shell structure cold-resistant reinforcing masterbatch;

[0186] The toughening component comprises a polyolefin elastomer and an ethylene-vinyl acetate copolymer in a mass ratio of 1:2.

[0187] The core-shell structure cold-resistant reinforced masterbatch was prepared by Example 4.

[0188] A method for preparing a high-strength, cold-resistant bridge and tunnel waterproofing and drainage board includes the following steps:

[0189] S1. Add the core-shell structure cold-resistant reinforced masterbatch, high-density polyethylene, and toughening components together into a high-speed mixer. Set the temperature to 80℃ and the rotation speed to 600rpm. Mix for 15 minutes to obtain the mixture.

[0190] S2. The mixture is melted and extruded through a sheet extruder. The sheet extruder is set with the following temperatures: feeding section 175℃, melting section 205℃, metering section 215℃, and die head 210℃. Then, it is calendered through a three-roll calender with the roller temperature set at 140℃ and the calendering speed at 5m / min to obtain a high-strength cold-resistant bridge and tunnel waterproofing and drainage board.

[0191] The comprehensive performance of the high-strength cold-resistant bridge and tunnel waterproofing and drainage boards in Examples 1-3 and Comparative Examples 1-6 of the present invention was tested respectively.

[0192] 1. Cold resistance test

[0193] 1.1 Low-temperature embrittlement test

[0194] Referring to GB / T 5470-2008 standard, 30 samples each from Examples 1-3 and Comparative Examples 1-6 were taken. After being kept at a test temperature of -50℃ for 5 minutes, the samples were subjected to impact tests using a low-temperature brittle impact testing machine. The number of fractured samples was recorded and counted. The impact head speed was set to 2.0 m / s.

[0195] 1.2 Low Temperature Bending Test

[0196] Take three samples (150mm × 25mm each) prepared in Examples 1-3 and Comparative Examples 1-6, and place them in a low-temperature chamber at -40℃ for 4 hours. Then, use a bending machine to fold the test sample 180° along the short side and return it to the starting position to perform a bending test. Record the number of bends when cracks or fractures appear in each group of test samples, and take the average number of bends in each group of test samples as the test result. If there is no damage after more than 50 bends, record it as ">50".

[0197] 2. Mechanical performance testing

[0198] 2.1 Tensile property test

[0199] The tensile strength and elongation at break of the samples were tested using a universal testing machine in accordance with ASTM D638 standard. The sample type was a type IV dumbbell-shaped specimen, and the test rate was 50 mm / min.

[0200] 2.2 Thermal stretching test

[0201] According to GB / T 2951.21-2008 standard, the test temperature is 200℃, the test time is 15min, and the load is 20N / cm. 2 The maximum elongation under test load and the permanent elongation after cooling were measured.

[0202] 3. Freeze-thaw cycle aging performance test

[0203] Samples obtained from Examples 1-3 and Comparative Examples 1-6 were immersed in water at 20°C for 24 hours, then frozen at -40°C for 8 hours, and then thawed in water at 20°C for 16 hours. This process was counted as one freeze-thaw cycle. After 100 freeze-thaw cycles, the samples were placed in a standard environment for 24 hours. The tensile strength and elongation at break after the freeze-thaw cycles were tested according to ASTM D638 standard, and the tensile strength retention rate and elongation at break retention rate after the freeze-thaw cycles were calculated.

[0204] Tensile strength retention rate (%) = (Tensile strength after freeze-thaw cycles / Tensile strength before freeze-thaw cycles) × 100%;

[0205] Elongation at break retention rate (%) = (Elongation at break after freeze-thaw cycles / Elongation at break before freeze-thaw cycles) × 100%.

[0206] The test results are shown in Table 1:

[0207] Table 1: Comprehensive performance test data of drainage boards in Examples 1-3 and Comparative Examples 1-6

[0208] Test Project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Low-temperature embrittlement (number of fractures / total number) 0 / 30 0 / 30 0 / 30 7 / 30 9 / 30 5 / 30 2 / 30 4 / 30 11 / 30 Low temperature bending (-40℃, times) ＞50 ＞50 ＞50 18 15 21 32 25 12 Tensile strength (MPa) 22.1 24.0 23.3 17.5 16.8 18.2 19.8 19.1 15.4 Elongation at break (%) 685 650 668 510 485 530 610 580 750 Maximum elongation (%) under thermal stretching load 55 50 48 95 102 88 65 72 >200 Permanent elongation after heat stretching and cooling (%) 5 3 2 18 23 15 8 11 >100 Tensile strength retention rate (%) 90.9 91.7 92.3 69.1 64.9 74.2 81.8 77.5 63.6 Elongation at break retention rate (%) 90.5 91.5 91.3 69.6 66.0 71.7 78.7 76.7 54.7

[0209] As shown in Table 1, the high-strength cold-resistant bridge and tunnel waterproofing boards prepared in Examples 1-3 of the present invention exhibit excellent comprehensive performance in terms of cold resistance, mechanical properties, thermal stability and resistance to freeze-thaw cycle aging, which is significantly better than that of Comparative Examples 1-6.

[0210] As shown in Example 1 and Comparative Examples 1-3: Comparative Example 1 suffers from weak interfacial interaction with nano-silica due to the low grafting rate of EPDM; Comparative Example 2, lacking silane groups grafted onto EPDM, exhibits severe agglomeration of nanofillers due to the absence of chemical bonds between EPDM and nano-silica; Comparative Example 3, employing physical blending, suffers from poor core-phase dispersion. Comparative Examples 1-3 demonstrate significantly lower performance retention rates than Example 1 in low-temperature embrittlement, low-temperature bending, tensile strength, and after freeze-thaw cycles. In summary, this invention achieves chemical bonding between EPDM and SiO2 by introducing a functional coupling agent and employs a core-shell structure to ensure uniform dispersion within the matrix.

[0211] As shown in Example 1 and Comparative Examples 4-5, although Comparative Example 4 (containing only POE) and Comparative Example 5 (containing only EVA) exhibit better cold resistance than Comparative Examples 1-3, their tensile strength and performance retention after freeze-thaw cycles are still significantly lower than those of Example 1. In summary, this demonstrates that POE and EVA have a synergistic effect in toughening and improving compatibility, and their combined use can better balance the stiffness, toughness, and long-term stability of the material.

[0212] As shown in Example 1 and Comparative Example 6, Comparative Example 6, without irradiation crosslinking, exhibited a maximum elongation >200% under thermal stretching load. The material directly melted during the thermal stretching test, failing to form an effective three-dimensional network structure. Furthermore, it had the lowest tensile strength and elongation at break retention rates after freeze-thaw cycles. This indicates that in the uncrosslinked system, the phase interfaces are easily separated under cyclic stress, leading to a rapid deterioration in performance. In contrast, Example 1, after irradiation, formed a stable semi-interpenetrating network structure, endowing the material with excellent thermal stability, dimensional stability, and anti-aging properties.

[0213] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A high-strength, cold-resistant bridge and tunnel waterproofing and drainage board, characterized in that, It is made from the following raw materials by weight through melt blending, calendering, and irradiation crosslinking; The raw materials include: 35-45 parts of high-density polyethylene, 30-40 parts of toughening components, and 20-30 parts of core-shell structure cold-resistant reinforcing masterbatch; The toughening component comprises a polyolefin elastomer and an ethylene-vinyl acetate copolymer.

2. The high-strength, cold-resistant bridge and tunnel waterproofing and drainage board according to claim 1, characterized in that, The mass ratio of the polyolefin elastomer to the ethylene-vinyl acetate copolymer is 1-2:1-2.

3. The high-strength, cold-resistant bridge and tunnel waterproofing and drainage board according to claim 1, characterized in that, The core-shell structure cold-resistant reinforced masterbatch consists of two parts: a core and a shell. The core is composed of functionalized modified EPDM rubber and nano-silica; The shell is composed of very low density polyethylene and maleic anhydride-grafted polyolefin compatibilizer.

4. The high-strength, cold-resistant bridge and tunnel waterproofing and drainage board according to claim 3, characterized in that, In the core-shell structure cold-resistant reinforcing masterbatch, the mass ratio of the core to the shell is 6-7:3-4.

5. The high-strength, cold-resistant bridge and tunnel waterproofing and drainage board according to claim 3, characterized in that, The mass ratio of functionalized modified EPDM rubber to nano-silica in the core is 6-7:

1.

6. The high-strength, cold-resistant bridge and tunnel waterproofing and drainage board according to claim 3, characterized in that, The functionalized modified EPDM rubber is prepared by the following method: a. Propyltriethoxysilane isocyanate and N-(2-hydroxyethyl)maleimide are reacted with a catalyst to undergo a polyurethane addition reaction to obtain a functional coupling agent; b. Ethylene propylene diene monomer (EPDM) rubber and a functional coupling agent are subjected to a melt grafting reaction under the action of a free radical initiator to obtain functionalized modified EPDM rubber.

7. The high-strength, cold-resistant bridge and tunnel waterproofing and drainage board according to claim 6, characterized in that, The mass ratio of propyltriethoxysilane isocyanate, N-(2-hydroxyethyl)maleimide, and catalyst in a is 10:5.5-6.5:0.01-0.

02.

8. The high-strength, cold-resistant bridge and tunnel waterproofing and drainage board according to claim 6, characterized in that, The mass ratio of EPDM rubber, functional coupling agent, and free radical initiator in part b is 100:5-7:0.2-0.

4.

9. The high-strength, cold-resistant bridge and tunnel waterproofing and drainage board according to claim 3, characterized in that, The mass ratio of ultra-low density polyethylene and maleic anhydride-grafted polyolefin compatibilizer in the shell is 8-10:

1.

10. A method for preparing a high-strength, cold-resistant bridge and tunnel drainage board according to any one of claims 1-9, characterized in that, Includes the following steps: S1. The core-shell structure cold-resistant reinforced masterbatch is mixed with high-density polyethylene and toughening components at high speed to obtain a mixture. S2. The mixture is melted and extruded through a sheet extruder and then calendered to obtain a semi-finished waterproof and drainage board. S3. Electron beam irradiation treatment is applied to the semi-finished drainage board to obtain a high-strength, cold-resistant bridge and tunnel drainage board.