Waterproof and drainage board with high compressive strength and tensile strength as well as preparation method and application of waterproof and drainage board

Abstract

The invention belongs to the technical field of waterproof and drainage boards, and provides a waterproof and drainage board with high compressive strength and tensile strength and a preparation method and application thereof.The waterproof and drainage board is formed by compounding an upper layer, a middle layer and a lower layer, and the upper layer and the lower layer are each prepared from 30-40 parts of high-density polyethylene, 10-20 parts of chlorinated polypropylene, 10-15 parts of metallocene polyethylene and 1-3 parts of carbon nanotubes; 2-5 parts of nano calcium carbonate, 1-5 parts of polyethylene wax, 1-3 parts of an antioxidant and 1-3 parts of an anti-ultraviolet agent; the middle layer is prepared from the following raw materials: 35 to 55 parts of linear low-density polyethylene, 15 to 30 parts of metallocene polyethylene, 10 to 15 parts of ethylene-vinyl acetate copolymer, 5 to 10 parts of POE (Polyolefin Elastomer), 5 to 10 parts of aramid chopped fiber, 1 to 3 parts of antioxidant and 1 to 3 parts of ultraviolet screening agent; the nano calcium carbonate is subjected to modification treatment. The waterproof and drainage board has relatively high compressive strength and tensile strength, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of waterproof and drainage plates, and relates to a waterproof and drainage plate with high compressive strength and tensile strength and a preparation method and application thereof. BACKGROUND

[0002] Leakage of road tunnels has become one of the core hidden dangers threatening the safe operation of high-speed railways. The frequent occurrence of leakage diseases not only leads to the deterioration of lining structures, secondary disasters such as mud boiling of ballast beds, but also may cause serious safety risks such as contact net leakage and track freezing, directly affecting the stability of train operation.

[0003] At present, the tunnel waterproof and drainage system generally adopts the "drainage first and then waterproof" process, and the core materials are waterproof plates and waterproof and drainage plates. Such plates are mostly made of resins such as polyethylene (PE) and polypropylene (PP) as the matrix, composite resin particles are prepared by adding fillers such as calcium carbonate and talc, and then processed by extrusion molding process. The waterproof and drainage plate needs to bear the vertical pressure (compressive requirement) from the upper soil layer and the structural load, and may also produce horizontal tensile stress (tensile requirement) due to tunnel deformation, backfill soil settlement or temperature change. For example, the lining structure of a railway tunnel will produce periodic deformation under train load, causing the drainage plate to be stretched. The waterproof and drainage plate needs to be tightly bonded with the waterproof layer, drainage blind ditch and concrete lining. If the tensile strength is insufficient, the interface is prone to separation due to stress concentration, which destroys the waterproof continuity; and if the compressive strength is insufficient, the drainage plate may collapse under the pressure of the filling soil, blocking the drainage channel. Therefore, the waterproof and drainage plate needs to have high compressive strength and tensile strength. Both are indispensable, and together determine the long-term stability and engineering safety of the material.

[0004] However, the resin matrix waterproof and drainage plate or waterproof plate in the prior art faces the challenge of being difficult to balance the compressive strength and tensile strength. This is because (1) anisotropy limitation: the mechanical properties of a single resin matrix (such as polyethylene, polypropylene) have significant directionality. For example, the extrusion molded plate has high compressive strength in the longitudinal direction (extrusion direction), but low tensile strength in the transverse direction, with a large difference between the two. This is due to the uneven performance caused by the directional arrangement of resin molecular chains. (2) Interaction between filler and matrix: traditional fillers (such as calcium carbonate) can improve the compressive strength, but will weaken the interfacial bonding force, leading to a decrease in tensile strength. (3) Influence of resin curing shrinkage: the curing shrinkage of resins such as polyester and vinyl ester is high, which easily produces residual stress in the material, leading to the trade-off between compressive strength and tensile strength.

[0005] For example, the Chinese patent with publication number CN111849061 A provides a composite resin composition, which includes component I, the component I includes metallocene polyethylene, light stabilizer and component II; wherein, the component II is selected from at least one of ultra-high molecular weight polyethylene, ethylene-vinyl acetate copolymer and high-density polyethylene, the scheme pays attention to improve the lifting performance, tear strength, puncture strength, and the comprehensive mechanical properties are excellent, but the contradiction that the compressive strength and tensile strength are considered at the same time is not solved.

[0006] In view of the above problems, the prior art attempts to improve the performance by optimizing the filler ratio (such as introducing nano-silicon dioxide, fiber reinforcement) or improving the processing technology (such as co-extrusion molding), but limited by the inherent characteristics of the resin matrix, the comprehensive mechanical properties are limited, and the cost is high. Therefore, developing a new type of waterproof drainage plate with high compressive strength and excellent tensile properties has become a key requirement to break through the bottleneck of tunnel leakage water treatment. SUMMARY

[0007] The present application provides a waterproof drainage plate with high compressive strength and tensile strength, and a preparation method and application thereof, which has high compressive strength and tensile strength, and good application prospect.

[0008] The technical scheme of the present application is as follows: A waterproof drainage plate with high compressive strength and tensile strength is composed of an upper layer, a middle layer and a lower layer, and the raw materials of the upper layer and the lower layer are the same; The raw material of the upper layer is composed of the following components in parts by weight: high-density polyethylene 30-40 parts, chlorinated polypropylene 10-20 parts, metallocene polyethylene 10-15 parts, carbon nanotubes 1-3 parts, nano calcium carbonate 2-5 parts, polyethylene wax 1-5 parts, antioxidant 1-3 parts, and ultraviolet inhibitor 1-3 parts; The raw material of the middle layer is composed of the following components in parts by weight: linear low-density polyethylene 35-55 parts, metallocene polyethylene 15-30 parts, ethylene-vinyl acetate copolymer 10-15 parts, POE 5-10 parts, aramid short fiber 5-10 parts, antioxidant 1-3 parts, and ultraviolet inhibitor 1-3 parts; The nano calcium carbonate is modified by silane coupling agent KH-550 and polyethylene glycol.

[0009] Preferably, the method for modifying the nano calcium carbonate by silane coupling agent and polyethylene glycol includes the following steps: The silane coupling agent KH-550 is weighed at 0.5%-2% of the mass of the nano calcium carbonate, the anhydrous ethanol is mixed with the silane coupling agent KH-550 at 3-5 times the mass of the nano calcium carbonate, then the mixture is mixed with the nano calcium carbonate, stirred at 80-120℃ and 500-1000rpm for 30-60min, then the polyethylene glycol is added at 1%-3% of the mass of the nano calcium carbonate, and the stirring is continued for 20-30min at a stirring rate of 500-1000rpm, and then dried.

[0010] Preferably, the molecular weight of the polyethylene glycol is 400-2000. If the molecular weight of the polyethylene glycol used is not within this range, the reinforcing effect of the nano calcium carbonate on the waterproof board will be affected.

[0011] Preferably, the molecular weight of the polyethylene glycol is 800-1200.

[0012] Preferably, the molecular weight of the polyethylene glycol is 1000.

[0013] Preferably, the particle size of the nano calcium carbonate is 40-80nm.

[0014] Preferably, the length of the aramid short-cut fiber is 3-25mm.

[0015] Preferably, the length of the aramid short-cut fiber is 6-12mm, which can be purchased from Yantai Taixingxing Material Science and Technology Co., Ltd.

[0016] Preferably, the drying step includes drying the nano calcium carbonate at 80-100℃ for 2-4 hours.

[0017] Preferably, the preparation method of the chlorinated polypropylene includes the following steps: the polypropylene is soaked in a solvent at 120-135℃, the modifier is added at 8-10% of the weight of the polypropylene under stirring, the reaction is carried out at 120-135℃ for 1.5-2.5h, alcohol precipitation is carried out, and then washed with water and dried, to obtain the chlorinated polypropylene, wherein the modifier is a mixture of isopropyl trichloroacetate and tert-butyl peroxide at a mass ratio of 1:1.

[0018] Preferably, the carbon nanotube is subjected to a modification treatment, and the modification treatment includes the following steps: S1, the carbon nanotube is subjected to acid treatment, washed and dried to obtain a pretreated carbon nanotube; S2, the silane coupling agent KH-550 is mixed with an aqueous ethanol solution, the concentration of the silane coupling agent KH-550 in the mixture is 0.5-2wt%, and the pH is adjusted to 3-5 with acetic acid to obtain a silane solution; S3, the pretreated carbon nanotube: silane solution is mixed in a dosage of 0.5-1g: 100ml, ultrasonic dispersion is carried out, and then refluxing is carried out at 50-90℃ for 2-6h, and then centrifugal washing and drying are carried out to obtain modified carbon nanotubes.

[0019] Preferably, the acid treatment comprises the following steps: mixing carbon nanotubes with concentrated sulfuric acid and concentrated nitric acid in a mass ratio of 1:2-4:1, stirring at a speed of 150-250rpm at 60℃ for 3.5-4.5h.

[0020] Preferably, the concentration of the ethanol aqueous solution is 50%-95wt%.

[0021] Preferably, the washing and drying step comprises: centrifugal washing with deionized water until neutral, and then drying in a vacuum drying oven at 60℃ for 10-14h.

[0022] Preferably, the ultrasonic step comprises: dispersing for 18-25min under ultrasonic conditions with a power of 250-300w and a frequency of 20-40kHz.

[0023] Preferably, the antioxidant is selected from one or more of antioxidants 1010, antioxidants 168, antioxidants MK-608.

[0024] Preferably, the ultraviolet resistant agent is selected from one or more of ultraviolet resistant agents UV-531, ultraviolet resistant agents UV-327, ultraviolet resistant agents UV-328.

[0025] Preferably, the thicknesses of the upper layer, the middle layer and the lower layer are 0.6±0.1mm, 0.8±0.2mm and 0.6±0.1mm respectively, and the total thickness is 2mm.

[0026] The application also provides a preparation method of the waterproof plate with high compressive strength and tensile strength. S1. A double-screw granulator is used to extrude and granulate the raw materials of the upper and lower layers, and after screw extrusion, drawing and granulation, the upper-layer master batch and the lower-layer master batch are prepared; S2. A double-screw granulator is used to extrude and granulate the raw materials of the middle layer, and after screw extrusion, drawing and granulation, the middle-layer master batch is prepared, wherein the aramid short-cut fibers are added from a side feeding port and other raw materials are added from a main feeding port; S3. A three-layer composite sheet extruder is used, the upper-layer master batch, the middle-layer master batch and the lower-layer master batch are respectively placed into corresponding feeding ports, and after extrusion by respective screws, the waterproof plate is prepared by compounding after embossed roller calendering.

[0027] The application also provides an application of the waterproof plate with high compressive strength and tensile strength in a railway tunnel.

[0028] The beneficial effects produced by the technical solutions of the present application are as follows: 1、 Through the synergistic effect of structural innovation (three-layer cooperation) and material modification (CNTs, nano calcium carbonate, POE, etc.), the present application realizes high compressive strength and high tensile strength of the waterproof board, which is suitable for complex engineering scenes such as railway tunnels.

[0029] 2、 Through the sandwich composite structure of the upper compressive layer, the middle tensile layer and the lower compressive layer, the present application realizes the synergistic optimization of mechanical properties; the beneficial effects of the raw materials of each part are as follows: In the present application, carbon nanotubes (CNTs) are added to the upper and lower raw materials, which effectively improves the crystallinity and interfacial bonding force of PE, and simultaneously enhances the compressive and tensile properties; wherein the carbon nanotubes are modified by silane coupling agent, which enhances the interfacial bonding force between the carbon nanotubes and the PE waterproof board, and helps to improve the overall performance of the waterproof board.

[0030] The addition of modified nano calcium carbonate in the present application can simultaneously improve the compressive strength and tensile properties of the waterproof board, which is better than ordinary calcium carbonate, and the modified nano calcium carbonate particles can avoid the cracking of the waterproof board caused by stress concentration.

[0031] The waterproof board added with modified PP in the present application can maintain relatively stable compressive properties under different temperature and humidity environments, ensuring long-term use effect.

[0032] The addition of POE in the present application can effectively balance the strength and elongation of the middle layer of the waterproof board.

[0033] The addition of aramid short fibers in the middle layer of the present application improves the tensile strength through "self-reinforcing effect", and in addition, the fiber has excellent compatibility with the PE matrix, and does not need to be treated with coupling agent like other fibers. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described below in conjunction with the embodiments of the present application, obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. All experimental methods or test methods involved in the embodiments of the present application are conventional methods in the prior art, and their names and / or abbreviations are conventional names in the art, which are very clear and definite in the relevant application field, and the skilled person in the art can understand the conventional process steps and use the corresponding equipment according to the conventional conditions or the conditions recommended by the manufacturer. The various instruments, equipment, raw materials or reagents used in the embodiments of the present application are not particularly limited in origin, and are conventional products that can be purchased through regular commercial channels, or can be prepared according to conventional methods well known to those skilled in the art.

[0036] In the following examples and comparative examples: The carbon nanotubes have a tube diameter of 10-20 nm and a tube length of 20 μm-100 μm; The polyethylene wax is LP1000 purchased from Yanshan Petrochemical, with a molecular weight of 3500-4500; The polypropylene is PP F800E from Shanghai Petrochemical; The high-density polyethylene in the upper layer raw material has a melt index of 0.1-1.2 g / 10 min and a density of 0.910-0.990 g / cm 3 ; specifically, the grade is Ningxia Baofeng 5502S or ExxonMobil HDPE 108; The metallocene polyethylene has a density of 0.918-0.920 g / cm³ and a melt index (190℃ / 2.16 kg): 3.5-5.0 g / 10 min; purchased from mLLDPE 3518PA / ExxonMobil; In the middle layer raw material, the linear low-density polyethylene has a density of 0.910-0.920 g / cm³ and a melt index (190℃, 2.16 kg) of 0.3-0.5 g / 10 min, purchased from LLDPE SP0540 of Polymer Composite Inc; The metallocene polyethylene has a density of 0.918-0.920 g / cm³ and a melt index (190℃ / 2.16 kg): 3.5-5.0 g / 10 min; purchased from mLLDPE 3518PA / ExxonMobil; The ethylene-vinyl acetate copolymer has a density of 0.930-0.950 g / cm³ and a melt index of 2.5-5.0 g / 10 min (190℃, 2.16 kg), purchased from EVA EV302 of Yupochem Industrial Co., Ltd.; POE density 0.850-0.882 g / cm3, melt index 0.5-5 g / 10 min (190°C, 2.16 kg), POE 875 purchased from SK Corporation, Korea; The length of aramid short fibers is 6 mm, and they are purchased from Yantai Taixingxing Material Science and Technology Co., Ltd.

[0037] The molecular weight of polyethylene glycol is 400-2000; The particle size of nano calcium carbonate is 40-80 nm; Concentrated sulfuric acid refers to a mass fraction of 95-98%; Concentrated nitric acid refers to a mass fraction of 65-68%.

[0038] Preparation Example 1 The modification treatment of nano calcium carbonate includes the following steps: First, dry the nano calcium carbonate at 90°C for 3 hours to remove water, and then put it into a high-speed mixer. Take 1% of the mass of the calcium carbonate as silane coupling agent KH-550, mix the silane coupling agent KH-550 with 4 times the mass of the nano calcium carbonate in anhydrous ethanol, and then mix the mixture with the nano calcium carbonate. Stir at 100°C and 800 rpm for 40 min, then add 2% of the mass of the nano calcium carbonate as polyethylene glycol (molecular weight 1000), continue to stir for 25 min at a stirring rate of 800 rpm, dry, and obtain modified nano calcium carbonate.

[0039] Preparation Example 2 The modification treatment of nano calcium carbonate includes the following steps: First, dry the nano calcium carbonate at 80°C for 4 hours to remove water, and then put it into a high-speed mixer. Take 0.5% of the mass of the calcium carbonate as silane coupling agent KH-550, mix the silane coupling agent KH-550 with 5 times the mass of the nano calcium carbonate in anhydrous ethanol, and then mix the mixture with the nano calcium carbonate. Stir at 80°C and 1000 rpm for 30 min, then add 3% of the mass of the nano calcium carbonate as polyethylene glycol (molecular weight 1200), continue to stir for 20 min at a stirring rate of 1000 rpm, dry, and obtain modified nano calcium carbonate.

[0040] Preparation Example 3 Modification treatment of nano calcium carbonate The modification treatment of nano calcium carbonate includes the following steps: The nano calcium carbonate is dried at 100°C for 2 hours to remove water, and then is put into a high-speed mixer. 2% of silane coupling agent KH-550 by weight of the nano calcium carbonate is weighed, and 3 times the weight of the nano calcium carbonate of anhydrous ethanol is mixed with the silane coupling agent KH-550. Then the mixture is mixed with the nano calcium carbonate, stirred at 120°C and 500 rpm for 60 minutes. Subsequently, 1% of polyethylene glycol (molecular weight 800) by weight of the nano calcium carbonate is added, and the stirring is continued for 30 minutes at a stirring rate of 500 rpm. The modified nano calcium carbonate is obtained after drying.

[0041] Preparation Example 4 The modification treatment of the carbon nanotubes includes the following steps: (1) The carbon nanotubes are pretreated by acid treatment, washed and dried to obtain pretreated carbon nanotubes; the acid treatment includes the following steps: the carbon nanotubes are mixed with concentrated sulfuric acid and concentrated nitric acid at a mass ratio of 1:3:1, stirred at 200 rpm at 60°C for 4 hours under reflux; the washing and drying step includes: centrifugation, washing with deionized water until neutral, and then drying in a vacuum drying oven at 60°C for 12 hours; (2) The silane coupling agent KH-550 is mixed with a 75wt% ethanol aqueous solution, the concentration of the silane coupling agent KH-550 in the mixture is 1wt%, and the pH is adjusted to 4 with acetic acid to obtain a silane solution; (3) The pretreated carbon nanotubes and the silane solution are mixed at a ratio of 0.8g:100mL, ultrasonically dispersed at 70°C for 4 hours, then washed by centrifugation and vacuum dried to obtain modified carbon nanotubes; the ultrasonic step includes: ultrasonic dispersion for 20 minutes under the conditions of a power of 300W and a frequency of 30kHz.

[0042] Preparation Example 5 The modification treatment of the carbon nanotubes includes the following steps: (1) The carbon nanotubes are pretreated by acid treatment, washed and dried to obtain pretreated carbon nanotubes; the acid treatment includes the following steps: the carbon nanotubes are mixed with concentrated sulfuric acid and concentrated nitric acid at a mass ratio of 1:3:1, stirred at 250 rpm at 60°C for 3.5 hours under reflux; the washing and drying step includes: centrifugation, washing with deionized water until neutral, and then drying in a vacuum drying oven at 60°C for 14 hours; (2) The silane coupling agent KH-550 is mixed with a 80wt% ethanol aqueous solution, the concentration of the silane coupling agent KH-550 in the mixture is 1.8wt%, and the pH is adjusted to 3.5 with acetic acid to obtain a silane solution; (3) mixing the pretreated carbon nanotubes and the silane solution in a ratio of 1 g: 100 mL, dispersing under ultrasonic condition with a power of 250 W and a frequency of 20 kHz for 25 minutes, refluxing at 80°C for 2 hours, washing by centrifugation, and vacuum drying to obtain the modified carbon nanotubes.

[0043] Preparation Example 6 The modification treatment of the carbon nanotubes comprises the following steps: (1) treating the carbon nanotubes by acid treatment, washing and drying to obtain pretreated carbon nanotubes; the acid treatment comprises the following steps: mixing the carbon nanotubes with concentrated sulfuric acid and concentrated nitric acid in a mass ratio of 1:3:1, stirring at a speed of 150 rpm under reflux at 60°C for 4.5 hours; the washing and drying step comprises: centrifugation, washing with deionized water until neutral, and then drying in a vacuum drying oven at 60°C for 10 hours; (2) mixing the silane coupling agent KH-550 with a 50%wt% ethanol aqueous solution, the concentration of the silane coupling agent KH-550 in the mixture being 0.8wt%, and adjusting the pH to 4.5 with acetic acid to obtain a silane solution; (3) mixing the pretreated carbon nanotubes and the silane solution in a ratio of 1 g: 100 mL, dispersing under ultrasonic condition with a power of 250 W and a frequency of 40 kHz for 18 minutes, refluxing at 50°C for 6 hours, washing by centrifugation, and vacuum drying to obtain the modified carbon nanotubes.

[0044] Example 1 A waterproof drainage board with high compressive strength and tensile strength is composed of an upper layer, a middle layer and a lower layer (the thicknesses of the upper layer, the middle layer and the lower layer are 0.6 mm, 0.8 mm and 0.6 mm respectively, and the total thickness is 2 mm), and the raw materials of the upper layer and the lower layer are the same; The raw material of the upper layer is composed of the following components in parts by weight: high-density polyethylene 35 parts (Ningxia Baofeng 5502S), chlorinated polypropylene 15 parts, metallocene polyethylene 12 parts (mLLDPE 3518PA / Exxon Mobil), carbon nanotubes 2 parts (prepared in Preparation Example 4), nano calcium carbonate 3 parts (prepared in Preparation Example 1), polyethylene wax 3 parts, antioxidant 2 parts (antioxidant 1010), and ultraviolet resistance agent 2 parts (ultraviolet resistance agent UV-328); the preparation method of the chlorinated polypropylene comprises the following steps: soaking polypropylene in o-dimethylbenzene (the use amount ratio of the polypropylene to the o-dimethylbenzene is 1 g: 10 mL) at 125°C, adding a modifier in an amount of 9% of the weight of the polypropylene under stirring, reacting at 130°C for 2 hours, alcohol precipitation, washing with water, and vacuum drying at 60°C; the modifier is isopropyl trichloroacetate and tert-butyl peroxide in a mass ratio of 1:1.

[0045] The raw material of the middle layer is composed of the following components by weight: linear low density polyethylene 40 parts, metallocene polyethylene 15 parts (mLLDPE 3518PA / Exxon Mobil), ethylene vinyl acetate copolymer 13 parts, POE 10 parts, aramid chopped fiber 8 parts, antioxidant 2 parts (antioxidant 1010), ultraviolet inhibitor 2 parts (ultraviolet inhibitor UV-328).

[0046] The preparation method of the waterproof board with high compressive strength and tensile strength comprises the following steps: S1. The raw materials of the upper and lower layers are extruded and granulated by a double screw granulator, and after screw extrusion, drawing, and granulation, the upper and lower master batches are prepared; S2. The raw material of the middle layer is extruded and granulated by a double screw granulator, and the aramid chopped fiber is added from the side feeding port and the other raw materials are added from the main feeding port, and after screw extrusion, drawing, and granulation, the middle layer master batch is prepared; S3. The upper, middle, and lower master batches are respectively placed into the corresponding feeding ports of a three-layer composite sheet extruder, and after extrusion by the respective screws, the composite is prepared by calendering through the concave-convex roller after extrusion by the respective screws, to prepare the waterproof board.

[0047] The temperature conditions of each zone of the double screw granulator include 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, and 220℃, the temperature conditions of the die head include 220℃, the vacuum degree is -0.06MPa, the water tank temperature is 50℃, the temperature control of each zone of the barrel of the composite sheet extruder includes 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, and 220℃, the temperature conditions of the die head include 220℃, and the vacuum degree is -0.08MPa.

[0048] Example 2 A waterproof board with high compressive strength and tensile strength is composed of an upper layer, a middle layer, and a lower layer (the thicknesses of the upper, middle, and lower layers are 0.6mm, 0.8mm, and 0.6mm respectively, and the total thickness is 2mm), and the raw materials of the upper and lower layers are the same; The raw material of the upper layer is composed of the following components in parts by weight: high-density polyethylene 30 parts (HDPE 108 of Exxon Mobil), chlorinated polypropylene 20 parts, metallocene polyethylene 10 parts (mLLDPE 3518PA / Exxon Mobil), carbon nanotubes 3 parts (prepared in Preparation Example 5), nano calcium carbonate 2 parts (prepared in Preparation Example 2), polyethylene wax 5 parts, antioxidant 1 part (antioxidant 168), and ultraviolet inhibitor 3 parts (ultraviolet inhibitor UV-327); the preparation method of the chlorinated polypropylene comprises the following steps: soaking polypropylene in o-xylene (the ratio of polypropylene to o-xylene is 1 g: 12 mL) at 120°C, adding 8% of the weight of polypropylene of a modifier under stirring, reacting at 135°C for 1.5 h, alcohol precipitation, washing with water, and vacuum drying at 60°C; the modifier is isopropyl trichloroacetate and tert-butyl peroxide in a mass ratio of 1:1.

[0049] The raw material of the middle layer is composed of the following components in parts by weight: linear low-density polyethylene 35 parts, metallocene polyethylene 30 parts (mLLDPE 3518PA / Exxon Mobil), ethylene-vinyl acetate copolymer 10 parts, POE 10 parts, aramid short-cut fiber 5 parts, antioxidant 3 parts (antioxidant MK-608), and ultraviolet inhibitor 1 part (ultraviolet inhibitor UV-327).

[0050] The preparation method of the waterproof drainage board with high compressive strength and tensile strength comprises the following steps: S1. The raw materials of the upper and lower layers are extruded and granulated by a double-screw granulator, and the upper-layer master batch and the lower-layer master batch are prepared after screw extrusion, drawing, and granulation; S2. The raw material of the middle layer is extruded and granulated by a double-screw granulator, and the aramid short-cut fiber is added from a side feeding port, and the other raw materials are added from a main feeding port, and the middle-layer master batch is prepared after screw extrusion, drawing, and granulation; S3. The upper-layer master batch, the middle-layer master batch, and the lower-layer master batch are respectively placed into corresponding feeding ports by a three-layer composite sheet extruder, and the waterproof drainage board is prepared after composite by respective screw extrusion and embossed roller calendering.

[0051] The temperature conditions of each zone of the double-screw granulator include 175°C, 185°C, 190°C, 205°C, 210°C, 220°C, 220°C, and 220°C; the temperature conditions of the head include 220°C; the vacuum degree is -0.06 MPa; and the water tank temperature is 50°C; the temperature control of each zone of the barrel of the composite sheet extruder includes 175°C, 185°C, 190°C, 205°C, 210°C, 220°C, 220°C, and 220°C; the temperature conditions of the head include 220°C; and the vacuum degree is -0.08 MPa.

[0052] Example 3 A waterproof and drainage board with high compressive strength and tensile strength, composed of an upper layer, a middle layer and a lower layer (the thickness of the upper layer, the middle layer and the lower layer are 0.6mm, 0.8mm and 0.6mm respectively, with a total thickness of 2mm), and the upper layer and the lower layer are made of the same material; The raw materials of the upper layer are composed of the following components in parts by weight: 40 parts of high-density polyethylene (Ningxia Baofeng 5502S), 10 parts of chlorinated polypropylene, 15 parts of metallocene polyethylene (mLLDPE 3518PA / ExxonMobil), 1 part of carbon nanotubes (prepared in Preparation Example 6), 5 parts of nano-calcium carbonate (prepared in Preparation Example 3), 1 part of polyethylene wax, 3 parts of antioxidant (antioxidant MK-608), and 1 part of anti-ultraviolet agent (anti-ultraviolet agent UV-531). The preparation method of the chlorinated polypropylene comprises the following steps: immersing polypropylene in o-xylene (the amount of polypropylene and o-xylene is 1g:8mL) at 135°C, adding a modifier of 10% by weight of the polypropylene under stirring, reacting at 120°C for 2.5h, precipitating with alcohol, washing with water, and vacuum drying at 60°C, wherein the modifier is isopropyl trichloroacetate and tert-butyl peroxide in a mass ratio of 1:1.

[0053] The raw materials of the middle layer are composed of the following components in parts by weight: 55 parts of linear low-density polyethylene, 20 parts of metallocene polyethylene (mLLDPE 3518PA / ExxonMobil), 15 parts of ethylene-vinyl acetate copolymer, 5 parts of POE, 10 parts of aramid short fibers, 1 part of antioxidant (antioxidant MK-608), and 3 parts of anti-ultraviolet agent (anti-ultraviolet agent UV-531).

[0054] The method for preparing the above-mentioned waterproof and drainage board with high compressive strength and tensile strength comprises the following steps: S1. The upper and lower layers of raw materials are extruded and granulated using a twin-screw granulator. After screw extrusion, stranding, and pelletizing, upper and lower masterbatches are produced. S2. A twin-screw pelletizer extrudes and pelletizes the middle layer raw materials. Aramid chopped fibers are added through a side feed port, and other raw materials are added through the main feed port. After screw extrusion, stranding, and pelletizing, the middle layer masterbatch is produced. S3. Using a three-layer composite sheet extruder, the upper, middle, and lower layer masterbatches are fed into their corresponding feed ports. After extrusion through their respective screws, they are rolled and compounded using a concave-convex roller to form a waterproof and drainage board.

[0055] The temperature conditions of each zone of the double-screw granulator include: 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, 220℃; the temperature condition of the head includes: 220℃; the vacuum degree: -0.06MPa; the water tank temperature: 50℃; the temperature control of each zone of the barrel of the composite sheet extruder: 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, 220℃; the temperature condition of the head includes: 220℃; the vacuum degree: -0.08MPa.

[0056] Example 4 A waterproof drainage board with high compressive strength and tensile strength is composed of an upper layer, a middle layer and a lower layer (the thicknesses of the upper layer, the middle layer and the lower layer are 0.6mm, 0.8mm and 0.6mm respectively, and the total thickness is 2mm), and the raw materials of the upper layer and the lower layer are the same; The raw material of the upper layer is composed of the following components in parts by weight: high-density polyethylene 35 parts (Ningxia Baofeng 5502S), chlorinated polypropylene 15 parts, metallocene polyethylene 12 parts (mLLDPE 3518PA / Exxon Mobil), carbon nanotubes 1 part (prepared in Preparation Example 4), nano calcium carbonate 5 parts (prepared in Preparation Example 2), polyethylene wax 1 part, antioxidant 3 parts (antioxidant 168), and ultraviolet resistance agent 1 part (ultraviolet resistance agent UV-328); the preparation method of the chlorinated polypropylene is the same as that in Example 1.

[0057] The raw material of the middle layer is composed of the following components in parts by weight: linear low-density polyethylene 55 parts, metallocene polyethylene 20 parts (mLLDPE 3518PA / Exxon Mobil), ethylene-vinyl acetate copolymer 15 parts, POE 5 parts, aramid short fiber 10 parts, antioxidant 1 part (antioxidant 168), and ultraviolet resistance agent 3 parts (ultraviolet resistance agent UV-328).

[0058] The preparation method of the waterproof drainage board with high compressive strength and tensile strength includes the following steps: S1. The raw materials of the upper and lower layers are extruded and granulated by a double-screw granulator, and after screw extrusion, drawing and granulation, the upper layer master batch and the lower layer master batch are prepared; S2. The raw material of the middle layer is extruded and granulated by a double-screw granulator, and aramid short fiber is added from the side feeding port and other raw materials are added from the main feeding port, and after screw extrusion, drawing and granulation, the middle layer master batch is prepared; S3. The upper layer master batch, the middle layer master batch and the lower layer master batch are respectively put into the corresponding feeding ports by using a three-layer composite sheet extruder, and after screw extrusion, the composite sheet is prepared by calendering through the concave-convex roller.

[0059] The temperature conditions of each zone of the double-screw granulator include: 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, 220℃; the temperature conditions of the head include: 220℃; the vacuum degree: -0.06MPa; the water tank temperature: 50℃; the temperature control of each zone of the barrel of the composite sheet extruder: 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, 220℃; the temperature conditions of the head include: 220℃; the vacuum degree: -0.08MPa.

[0060] Example 5 A waterproof drainage board with high compressive strength and tensile strength is composed of an upper layer, a middle layer and a lower layer (the thicknesses of the upper layer, the middle layer and the lower layer are 0.6mm, 0.8mm and 0.6mm respectively, and the total thickness is 2mm), and the raw materials of the upper layer and the lower layer are the same; The raw material of the upper layer is composed of the following components in parts by weight: high-density polyethylene 38 parts (Ningxia Baofeng 5502S), chlorinated polypropylene 12 parts, metallocene polyethylene 14 parts (mLLDPE 3518PA / Exxon Mobil), carbon nanotubes 2 parts (prepared in Preparation Example 5), nano calcium carbonate 3 parts (prepared in Preparation Example 1), polyethylene wax 3 parts, antioxidant 2 parts (antioxidant 1010), and ultraviolet resistance agent 2 parts (ultraviolet resistance agent UV-327); the preparation method of the chlorinated polypropylene is the same as that in Example 1.

[0061] The raw material of the middle layer is composed of the following components in parts by weight: linear low-density polyethylene 50 parts, metallocene polyethylene 15 parts (mLLDPE 3518PA / Exxon Mobil), ethylene-vinyl acetate copolymer 11 parts, POE 10 parts, aramid short fiber 8 parts, antioxidant 2 parts (antioxidant 1010), and ultraviolet resistance agent 2 parts (ultraviolet resistance agent UV-327).

[0062] The preparation method of the waterproof drainage board with high compressive strength and tensile strength includes the following steps: S1. The raw materials of the upper and lower layers are extruded and granulated by a double-screw granulator, and after screw extrusion, drawing and granulation, the upper layer master batch and the lower layer master batch are prepared; S2. The raw material of the middle layer is extruded and granulated by a double-screw granulator, and aramid short fiber is added from the side feeding port and other raw materials are added from the main feeding port, and after screw extrusion, drawing and granulation, the middle layer master batch is prepared; S3. The upper layer master batch, the middle layer master batch and the lower layer master batch are respectively put into the corresponding feeding ports by using a three-layer composite sheet extruder, and after screw extrusion, calendering and compounding, the waterproof drainage board is prepared.

[0063] The temperature conditions of each zone of the double-screw granulator include: 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, 220℃; the temperature conditions of the head include: 220℃; the vacuum degree is: -0.06MPa; the water tank temperature is: 50℃; the temperature control of each zone of the barrel of the composite sheet extruder includes: 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, 220℃; the temperature conditions of the head include: 220℃; the vacuum degree is: -0.08MPa.

[0064] Comparative Example 1 Compared with Example 1, the only difference is that the upper layer, the middle layer and the lower layer all use the upper layer raw material, and the waterproof board has a thickness of 2mm.

[0065] The preparation method of the waterproof board includes the following steps: S1. The double-screw granulator is used to extrude and granulate the upper layer raw material, and after screw extrusion, drawing and granulation, the master batch is prepared; S2. The sheet extruder is used to put the master batch into the corresponding feeding port, and after screw extrusion, the composite is prepared by calendering through the concave-convex roller, and the waterproof board is prepared.

[0066] The temperature conditions of each zone of the double-screw granulator include: 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, 220℃; the temperature conditions of the head include: 220℃; the vacuum degree is: -0.06MPa; the water tank temperature is: 50℃; the temperature control of each zone of the barrel of the composite sheet extruder includes: 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, 220℃; the temperature conditions of the head include: 220℃; the vacuum degree is: -0.08MPa.

[0067] Comparative Example 2 Compared with Example 1, the only difference is that the upper layer, the middle layer and the lower layer all use the middle layer raw material, and the waterproof board has a thickness of 2mm.

[0068] The preparation method of the waterproof board includes the following steps: S1. The double-screw granulator is used to extrude and granulate the middle layer raw material, and after screw extrusion, drawing and granulation, the master batch is prepared; S2. The sheet extruder is used to put the master batch into the corresponding feeding port, and after screw extrusion, the composite is prepared by calendering through the concave-convex roller, and the waterproof board is prepared.

[0069] The temperature conditions of each zone of the twin-screw granulator include 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, 220℃; the temperature conditions of the head include 220℃; the vacuum degree is -0.06MPa; the water tank temperature is 50℃; the temperature control of each zone of the barrel of the sheet extruder includes 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, 220℃; the temperature conditions of the head include 220℃; the vacuum degree is -0.08MPa.

[0070] Comparative Example 3 Compared with Example 1, the only difference is that the nano calcium carbonate is only modified by silane coupling agent KH-550. The specific steps are as follows: First, dry the nano calcium carbonate at 90℃ for 3 hours to remove water, and then put it into a high-speed mixer. Weigh 1% of silane coupling agent KH-550 based on the mass of calcium carbonate, mix it with 4 times the mass of nano calcium carbonate in anhydrous ethanol, then mix the mixture with nano calcium carbonate, stir at 100℃ and 800rpm for 40min, dry, and obtain modified nano calcium carbonate.

[0071] Comparative Example 4 Compared with Example 1, the only difference is that the nano calcium carbonate is only modified by polyethylene glycol. The specific steps are as follows: First, dry the nano calcium carbonate at 90℃ for 3 hours to remove water, and then put it into a high-speed mixer. Mix it with 4 times the mass of nano calcium carbonate in anhydrous ethanol, then mix the mixture with nano calcium carbonate, stir at 100℃ and 800rpm for 40min, then add 2% of polyethylene glycol (molecular weight 1000) based on the mass of nano calcium carbonate, continue to stir for 25min at a stirring rate of 800rpm, dry, and obtain modified nano calcium carbonate.

[0072] Comparative Example 5 Compared with Example 1, the only difference is that the nano calcium carbonate is not modified.

[0073] Comparative Example 6 Compared with Example 1, the only difference is that the carbon nanotubes are not modified.

[0074] Comparative Example 7 Compared with Example 1, the only difference is that the upper layer does not use chlorinated polypropylene, and the amount of high-density polyethylene is increased to 50 parts. Specifically, the raw materials of the upper layer are composed of the following components by weight: high-density polyethylene 50 parts (Ningxia Baofeng 5502S), metallocene polyethylene 12 parts (mLLDPE 3518PA / Exxon Mobil), carbon nanotubes 2 parts (prepared in Preparation Example 4), nano calcium carbonate 3 parts (prepared in Preparation Example 1), polyethylene wax 3 parts, antioxidant 2 parts (antioxidant 1010), and ultraviolet inhibitor 2 parts (ultraviolet inhibitor UV-328).

[0075] Comparative Example 8 Compared with Example 1, the only difference is that the upper layer does not use high-density polyethylene, and the amount of chlorinated polypropylene is increased to 50 parts. Specifically, the raw materials of the upper layer are composed of the following components by weight: chlorinated polypropylene 50 parts, metallocene polyethylene 12 parts (mLLDPE 3518PA / Exxon Mobil), carbon nanotubes 2 parts (prepared in Preparation Example 4), nano calcium carbonate 3 parts (prepared in Preparation Example 1), polyethylene wax 3 parts, antioxidant 2 parts (antioxidant 1010), and ultraviolet inhibitor 2 parts (ultraviolet inhibitor UV-328); the preparation method of the chlorinated polypropylene comprises the following steps: polypropylene is soaked in o-xylene (the amount of polypropylene to o-xylene is 1g:10mL) at 125℃, 9% of the weight of the polypropylene is added under stirring, and the modified agent is reacted at 130℃ for 2h, alcohol precipitation, water washing, and vacuum drying at 60℃. The modified agent is isopropyl trichloroacetate and tert-butyl peroxide with a mass ratio of 1:1.

[0076] Comparative Example 9 Compared with Example 1, the only difference is that the middle layer does not use metallocene polyethylene, and the amount of linear low-density polyethylene and POE is increased. Specifically, the raw materials of the middle layer are composed of the following components by weight: linear low-density polyethylene 52 parts, ethylene-vinyl acetate copolymer 13 parts, POE 13 parts, aramid chopped fiber 8 parts, antioxidant 2 parts (antioxidant 1010), and ultraviolet inhibitor 2 parts (ultraviolet inhibitor UV-328).

[0077] Effect Example: Mechanical Property Test The waterproof and drainage plates obtained by the examples and comparative examples were respectively tested for compressive strength, tensile strength, elongation at break, tear strength, and puncture strength, and the mechanical property test results are shown in Table 1.

[0078] Performance test indicators and methods are as follows: The determination of compressive strength is in accordance with QCR562.3-2018.

[0079] Tensile strength, elongation at break: the determination of tensile properties is carried out according to the provisions of GB / T 1040.2, the tensile speed is (250±50) mm / min, and the specific value is 250 mm / min; Tear strength: the determination of tear strength is carried out according to GB / T 529 without notched right-angle sample, the tensile speed is (250±50) mm / min, and the specific value is 250 mm / min; Puncture strength: the determination of puncture strength is carried out according to the provisions of national standard QCR562.3-2018.

[0080] Table 1 The temperature range of a certain tunnel throughout the year is -20℃~35℃, and the humidity range is 30%~50%. The test conditions of the compression strength of the waterproof board are set as follows: humidity 30%, temperature -20℃; humidity 50%, temperature 35℃. After 3 months, the compression strength of the examples 1-5 can still remain relatively stable (attenuation <5%), which can ensure the long-term use effect. However, the compression strength of the comparative examples 1-2 attenuates by more than 5% after 3 months.

[0081] The above is only a preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. The drainage board has high compressive strength and tensile strength, characterized by: It is composed of an upper layer, a middle layer and a lower layer, and the upper layer and the lower layer are made of the same material; The raw materials of the upper layer are composed of the following components in parts by weight: 30-40 parts of high-density polyethylene, 10-20 parts of chlorinated polypropylene, 10-15 parts of metallocene polyethylene, 1-3 parts of carbon nanotubes, 2-5 parts of nano-calcium carbonate, 1-5 parts of polyethylene wax, 1-3 parts of antioxidant, and 1-3 parts of anti-ultraviolet agent; The raw materials of the middle layer are composed of the following components in parts by weight: 35-55 parts of linear low-density polyethylene, 15-30 parts of metallocene polyethylene, 10-15 parts of ethylene-vinyl acetate copolymer, 5-10 parts of POE, 5-10 parts of aramid short fibers, 1-3 parts of antioxidant, and 1-3 parts of anti-ultraviolet agent; The nano calcium carbonate is modified by using silane coupling agent KH-550 and polyethylene glycol.

2. The anti-drainage board with high compressive strength and tensile strength according to claim 1, characterized in that: The method for modifying nano-calcium carbonate by a silane coupling agent and polyethylene glycol comprises the following steps: Weigh 0.5%-2% of the mass of nano-calcium carbonate as silane coupling agent KH-550, mix the silane coupling agent KH-550 with anhydrous ethanol 3-5 times the mass of the nano-calcium carbonate, then mix the mixed solution with the nano-calcium carbonate, stir at 80-120° C. and 500-1000 rpm for 30-60 minutes, then add polyethylene glycol at 1%-3% of the mass of the nano-calcium carbonate, continue stirring for 20-30 minutes at a stirring rate of 500-1000 rpm, and dry to obtain the product.

3. The anti-drainage board with high compressive strength and tensile strength according to claim 2, characterized in that: The molecular weight of the polyethylene glycol is 400-2000.

4. The anti-drainage board with high compressive strength and tensile strength according to claim 2, characterized in that: The particle size of the nano calcium carbonate is 40-80 nm.

5. The anti-drainage board with high compressive strength and tensile strength according to claim 1, characterized in that: The preparation method of chlorinated polypropylene comprises the following steps: immersing polypropylene in a solvent at 120-135° C., adding a modifier in an amount of 8-10% by weight of the polypropylene under stirring, reacting at 120-135° C. for 1.5-2.5 hours, precipitating with alcohol, washing with water, and drying to obtain the chlorinated polypropylene, wherein the modifier is isopropyl trichloroacetate and tert-butyl peroxide in a mass ratio of 1:

1.

6. The drainage board with high compressive strength and tensile strength according to claim 1, characterized in that: The carbon nanotubes are subjected to a modification process, and the modification process comprises the following steps: S1, treating carbon nanotubes with acid, washing and drying to obtain pretreated carbon nanotubes; S2, mixing silane coupling agent KH-550 with ethanol aqueous solution, wherein the concentration of silane coupling agent KH-550 in the mixture is 0.5-2wt%, and adjusting the pH to 3-5 with acetic acid to obtain a silane solution; S3. Pretreated carbon nanotubes and silane solution are mixed in an amount of 0.5-1 g: 100 mL, and after ultrasonic dispersion, the mixture is refluxed at 50-90° C. for 2-6 h, and then centrifuged and washed, and dried to obtain modified carbon nanotubes.

7. The drainage board with high compressive strength and tensile strength according to claim 1, characterized in that: The antioxidant is selected from one or more of antioxidant 1010, antioxidant 168, and antioxidant MK-608.

8. The anti-drainage board with high compressive strength and tensile strength according to claim 1, characterized in that: The anti-ultraviolet agent is selected from one or more of the anti-ultraviolet agent UV-531, anti-ultraviolet agent UV-327, and anti-ultraviolet agent UV-328.

9. The method for preparing a waterproof and drainage board with high compressive strength and tensile strength according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. The upper and lower layers of raw materials are extruded and granulated using a twin-screw granulator. After screw extrusion, stranding, and pelletizing, upper and lower masterbatches are produced. S2. A twin-screw pelletizer extrudes and pelletizes the middle layer raw materials. Aramid chopped fibers are added through a side feed port, and other raw materials are added through the main feed port. After screw extrusion, stranding, and pelletizing, the middle layer masterbatch is produced. S3. Using a three-layer composite sheet extruder, the upper, middle, and lower layer masterbatches are fed into their corresponding feed ports. After extrusion through their respective screws, they are rolled and compounded using a concave-convex roller to form a waterproof and drainage board.

10. Use of the waterproof and drainage board with high compressive strength and tensile strength according to any one of claims 1 to 8 in a railway tunnel.

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