Waterproof and drainage board with high compressive strength and tensile strength, preparation method and application thereof

Abstract

The application belongs to the technical field of waterproof drainage plates, and discloses a waterproof drainage plate with high compressive strength and tensile strength, a preparation method and application. The waterproof drainage plate is composed of an upper layer, a middle layer and a lower layer. The raw materials of the upper layer and the lower layer are composed of 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 an antioxidant and 1-3 parts of an ultraviolet resistance agent. The raw materials of the middle layer are composed of 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-cut fibers, 1-3 parts of an antioxidant and 1-3 parts of an ultraviolet resistance agent. The nano calcium carbonate is subjected to modification treatment. The waterproof drainage plate has 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 mechanical comprehensive performance is 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 property is improved limitedly, and the cost is high. Therefore, developing a new type of waterproof drainage plate with high compressive strength and excellent tensile performance 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:

[0009] 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;

[0010] 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 nanotube 1-3 parts, nano calcium carbonate 2-5 parts, polyethylene wax 1-5 parts, antioxidant 1-3 parts, and ultraviolet inhibitor 1-3 parts;

[0011] 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;

[0012] The nano calcium carbonate is modified by silane coupling agent KH-550 and polyethylene glycol.

[0013] Preferably, the method for modifying the nano calcium carbonate by silane coupling agent and polyethylene glycol includes the following steps:

[0014] 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 speed of 500-1000rpm, and then dried.

[0015] 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.

[0016] Preferably, the molecular weight of the polyethylene glycol is 800-1200.

[0017] Preferably, the molecular weight of the polyethylene glycol is 1000.

[0018] Preferably, the particle size of the nano calcium carbonate is 40-80nm.

[0019] Preferably, the length of the aramid short-cut fiber is 3-25mm.

[0020] 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.

[0021] Preferably, the drying step includes drying the nano calcium carbonate at 80-100℃ for 2-4 hours.

[0022] 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, wherein the modifier is isopropyl trichloroacetate and tert-butyl peroxide at a mass ratio of 1:1.

[0023] Preferably, the carbon nanotube is subjected to a modification treatment, and the modification treatment includes the following steps:

[0024] S1, the carbon nanotube is pretreated by acid treatment, washed and dried to obtain a pretreated carbon nanotube;

[0025] S2, the silane coupling agent KH-550 is mixed with an ethanol aqueous 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;

[0026] S3, mixing the pretreated carbon nanotube: silane solution in a ratio of 0.5-1g: 100mL, ultrasonic dispersion, then refluxing at 50-90℃ for 2-6h, centrifugal washing and drying to obtain modified carbon nanotubes.

[0027] Preferably, the acid treatment comprises the following steps: mixing carbon nanotubes with concentrated sulfuric acid, concentrated nitric acid in a mass ratio of 1:2-4:1, stirring at 150-250rpm at 60℃ for 3.5-4.5h.

[0028] Preferably, the concentration of the ethanol aqueous solution is 50%-95wt%.

[0029] 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.

[0030] Preferably, the ultrasonic step comprises: dispersing for 18-25min under ultrasonic conditions with a power of 250-300W and a frequency of 20-40kHz.

[0031] Preferably, the antioxidant is selected from one or more of antioxidant 1010, antioxidant 168, antioxidant MK-608.

[0032] Preferably, the ultraviolet resistant agent is selected from one or more of ultraviolet resistant agent UV-531, ultraviolet resistant agent UV-327, ultraviolet resistant agent UV-328.

[0033] Preferably, the thickness of the upper layer, middle layer and lower layer is 0.6±0.1mm, 0.8±0.2mm and 0.6±0.1mm respectively, and the total thickness is 2mm.

[0034] The application also provides a preparation method of the waterproof plate with high compressive strength and tensile strength, comprising the following steps:

[0035] S1. Using a double-screw granulator to extrude and granulate the raw materials of the upper and lower layers, and then making upper layer masterbatch and lower layer masterbatch after screw extrusion, drawing and pelletizing;

[0036] S2. Using a double-screw granulator to extrude and granulate the raw materials of the middle layer, and then making middle layer masterbatch after screw extrusion, drawing and pelletizing, with aramid short fibers added from a side feeding port and other raw materials added from a main feeding port;

[0037] S3. Using a three-layer composite sheet extruder to put the upper layer masterbatch, middle layer masterbatch and lower layer masterbatch into corresponding feeding ports respectively, and then making the waterproof plate after extruding through respective screws and then compounding after embossing and calendering.

[0038] The application also provides application of the waterproof board with high compression strength and tensile strength in a railway tunnel.

[0039] The application has the beneficial effects as follows:

[0040] 1. In the application, the high compression strength and high tensile strength of the waterproof board are realized through the synergistic effect of structural innovation (three-layer cooperation) and material modification (CNTs, nano calcium carbonate, POE, etc.), and the waterproof board is suitable for complex engineering scenes such as railway tunnels.

[0041] 2. In the application, the sandwich composite structure of the upper compression layer, the middle tensile layer and the lower compression layer realizes the synergistic optimization of mechanical properties; the beneficial effects of the raw materials of each part are as follows:

[0042] In the application, the carbon nanotubes (CNTs) added in the upper layer and the lower layer effectively improve the crystallinity and interfacial bonding force of PE, and simultaneously enhance the compression and tensile properties; the carbon nanotubes are modified by using a 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.

[0043] The addition of the modified nano calcium carbonate in the application can simultaneously improve the compression strength and tensile properties of the waterproof board, and the effect is better than that of ordinary calcium carbonate; meanwhile, the modified nano calcium carbonate particles can avoid the cracking of the waterproof board caused by stress concentration.

[0044] The waterproof board added with modified PP in the application can still maintain relatively stable compression performance in different temperature and humidity environments, and ensure long-term use effect.

[0045] The addition of POE in the application can effectively balance the strength and elongation of the middle layer of the waterproof board.

[0046] The addition of aramid short fibers in the middle layer of the application improves the tensile strength through the "self-reinforcing effect", and in addition, the fiber has excellent compatibility with the PE matrix, and does not need to be treated by a coupling agent like other fibers. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0048] 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 publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of a conflict in terminology, the present specification controls. If a term in the present specification is found missing or ambiguous, it can be interpreted as a term commonly used in the field of the present application. In the present application, the experimental methods or test methods involved in the embodiments, if not specifically stated, are conventional methods in the prior art, and the name and / or abbreviation thereof are conventional names in the field, which are very clear and definite in the field of use, 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 specially limited in terms of source, and are conventional products that can be purchased through regular commercial channels, or can be prepared according to the conventional methods well known to those skilled in the art.

[0049] In the following examples and comparative examples:

[0050] The carbon nanotubes have a tube diameter of 10-20 nm and a tube length of 20 μm-100 μm;

[0051] The polyethylene wax is LP1000 purchased from Yanshan Petrochemical, with a molecular weight of 3500-4500;

[0052] The polypropylene is PP F800E from Shanghai Petrochemical;

[0053] 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;

[0054] The metallocene polyethylene has a density of 0.918-0.920 g / cm³ and a melt index (190°C / 2.16 kg): 3.5-5.0 g / 10 min; purchased from mLLDPE 3518PA / ExxonMobil;

[0055] 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°C, 2.16 kg) of 0.3-0.5 g / 10 min, purchased from LLDPE SP0540 of Polymer Composite Inc;

[0056] The metallocene polyethylene has a density of 0.918-0.920 g / cm³ and a melt index (190°C / 2.16 kg): 3.5-5.0 g / 10 min; purchased from mLLDPE 3518PA / ExxonMobil;

[0057] Ethylene-vinyl acetate copolymer with density of 0.930-0.950 g / cm3 and melt index of 2.5-5.0 g / 10 min (190℃, 2.16 kg), EVA EV302 purchased from YAPRO CHEMICAL INDUSTRY CO., LTD;

[0058] POE with density of 0.850-0.882 g / cm3 and melt index of 0.5-5 g / 10 min (190℃, 2.16 kg), POE 875 purchased from SK Corporation, Korea;

[0059] Aramid short fibers with length of 6 mm, purchased from Yantai Taixingxing Material Science and Technology Co., Ltd.

[0060] Polyethylene glycol with molecular weight of 400-2000;

[0061] Nano calcium carbonate with particle size of 40-80 nm;

[0062] Concentrated sulfuric acid refers to mass fraction of 95-98%;

[0063] Concentrated nitric acid refers to mass fraction of 65-68%.

[0064] Preparation Example 1

[0065] The modification treatment of nano calcium carbonate includes the following steps:

[0066] First, dry the nano calcium carbonate at 90℃ for 3 hours to remove water, and then put it into a high-speed mixer. Take 1% of silane coupling agent KH-550 by mass of the calcium carbonate, and mix the silane coupling agent KH-550 with 4 times the mass of anhydrous ethanol. Then mix the mixture with the nano calcium carbonate, and stir at 100℃ and 800 rpm for 40 min. Then add 2% of polyethylene glycol (molecular weight 1000) by mass of the nano calcium carbonate, and continue to stir for 25 min at a stirring rate of 800 rpm. Dry to obtain modified nano calcium carbonate.

[0067] Preparation Example 2

[0068] The modification treatment of nano calcium carbonate includes the following steps:

[0069] First, dry the nano calcium carbonate at 80℃ for 4 hours to remove water, and then put it into a high-speed mixer. Take 0.5% of silane coupling agent KH-550 by mass of the calcium carbonate, and mix the silane coupling agent KH-550 with 5 times the mass of anhydrous ethanol. Then mix the mixture with the nano calcium carbonate, and stir at 80℃ and 1000 rpm for 30 min. Then add 3% of polyethylene glycol (molecular weight 1200) by mass of the nano calcium carbonate, and continue to stir for 20 min at a stirring rate of 1000 rpm. Dry to obtain modified nano calcium carbonate.

[0070] Preparation Example 3

[0071] Modification of nano calcium carbonate

[0072] The modification of nano calcium carbonate comprises the following steps:

[0073] The nano calcium carbonate is first dried at 100°C for 2 hours to remove water, and then put into a high-speed mixer after cooling. 2% of silane coupling agent KH-550 by mass of the calcium carbonate is weighed, and 3 times the mass 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, and then 1% of polyethylene glycol (molecular weight 800) by mass of the nano calcium carbonate is added, and stirring is continued for 30 minutes at a stirring rate of 500 rpm. After drying, the modified nano calcium carbonate is obtained.

[0074] Preparation Example 4

[0075] The modification of carbon nanotubes comprises the following steps:

[0076] (1) The carbon nanotubes are treated with acid, washed and dried 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 200 rpm at 60°C for 4 hours under reflux; 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 12 hours;

[0077] (2) The silane coupling agent KH-550 is mixed with 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;

[0078] (3) The pretreated carbon nanotubes and the silane solution are mixed in 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 comprises: ultrasonic dispersion under the conditions of a power of 300W and a frequency of 30kHz for 20 minutes.

[0079] Preparation Example 5

[0080] The modification of carbon nanotubes comprises the following steps:

[0081] (1) The carbon nanotubes are pretreated 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 at a mass ratio of 1:3:1, stirring at a speed of 250 rpm at 60°C for 3.5 hours under reflux; 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 14 hours;

[0082] (2) The silane coupling agent KH-550 is mixed with an 80wt% ethanol aqueous solution, the concentration of the silane coupling agent KH-550 in the mixed solution is 1.8wt%, and acetic acid is used to adjust the pH to 3.5 to obtain a silane solution;

[0083] (3) The pretreated carbon nanotubes and the silane solution are mixed at a ratio of 0.5g:100mL, ultrasonic dispersion is performed at 80°C for 2 hours under reflux, and then centrifugation, washing and vacuum drying are performed to obtain modified carbon nanotubes; the ultrasonic dispersion step comprises: ultrasonic dispersion for 25 minutes under the condition of a power of 250W and a frequency of 20kHz.

[0084] Preparation Example 6

[0085] The modification treatment of the carbon nanotubes comprises the following steps:

[0086] (1) The carbon nanotubes are pretreated 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 at a mass ratio of 1:3:1, stirring at a speed of 150 rpm at 60°C for 4.5 hours under reflux; 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;

[0087] (2) The silane coupling agent KH-550 is mixed with a 50wt% ethanol aqueous solution, the concentration of the silane coupling agent KH-550 in the mixed solution is 0.8wt%, and acetic acid is used to adjust the pH to 4.5 to obtain a silane solution;

[0088] (3) The pretreated carbon nanotubes and the silane solution are mixed at a ratio of 1g:100mL, ultrasonic dispersion is performed at 50°C for 6 hours under reflux, and then centrifugation, washing and vacuum drying are performed to obtain modified carbon nanotubes; the ultrasonic dispersion step comprises: ultrasonic dispersion for 18 minutes under the condition of a power of 250W and a frequency of 40kHz.

[0089] Example 1

[0090] 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;

[0091] The raw material of the upper layer is composed of the following components 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), ultraviolet inhibitor 2 parts (ultraviolet inhibitor UV-328); the preparation method of the chlorinated polypropylene comprises the following steps: soaking polypropylene in o-xylene (the use amount ratio of polypropylene to o-xylene is 1 g:10 mL) at 125 ℃, adding 9% of the weight of polypropylene of a modifier under stirring, reacting at 130 ℃ for 2 h, alcohol precipitation, washing with water, and vacuum drying at 60 ℃; the modifier is isopropyl trichloroacetate and tert-butyl peroxide with a mass ratio of 1:1.

[0092] 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 short fiber 8 parts, antioxidant 2 parts (antioxidant 1010), ultraviolet inhibitor 2 parts (ultraviolet inhibitor UV-328).

[0093] The preparation method of the waterproof drainage board with high compressive strength and tensile strength comprises the following steps:

[0094] 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;

[0095] S2. The raw material of the middle layer is extruded and granulated by a double-screw granulator, and the aramid short 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;

[0096] 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.

[0097] The temperature conditions of each zone of the double-screw granulator include 175 ℃, 185 ℃, 190 ℃, 205 ℃, 210 ℃, 220 ℃, 220 ℃, and 220 ℃; the temperature condition of the die head includes 220 ℃; the vacuum degree is -0.06 MPa; and 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 condition of the die head includes 220 ℃; and the vacuum degree is -0.08 MPa.

[0098] Example 2

[0099] A waterproof board with high compressive strength and tensile strength, which 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), the raw materials of the upper layer and the lower layer are the same;

[0100] 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 amount of polypropylene to o-xylene is 1 g: 12 mL) at 120°C, adding a modifier in an amount of 8% of the weight of the polypropylene under stirring, reacting at 135°C for 1.5 h, alcohol precipitation, washing with water, and vacuum drying at 60°C; the modifier is a mixture of isopropyl trichloroacetate and tert-butyl peroxide in a mass ratio of 1:1.

[0101] 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 fiber 5 parts, antioxidant 3 parts (antioxidant MK-608), and ultraviolet inhibitor 1 part (ultraviolet inhibitor UV-327).

[0102] The preparation method of the waterproof board with high compressive strength and tensile strength comprises the following steps:

[0103] S1. Using a double-screw granulator to extrude and granulate the raw materials of the upper and lower layers, and after screw extrusion, drawing, and granulation, upper layer masterbatch and lower layer masterbatch are prepared;

[0104] S2. Using a double-screw granulator to extrude and granulate the raw material of the middle layer, and after screw extrusion, drawing, and granulation, middle layer masterbatch is prepared, with aramid short fiber being added from a side feeding port and other raw materials being added from a main feeding port;

[0105] S3. Using a three-layer composite sheet extruder, the upper layer masterbatch, the middle layer masterbatch and the lower layer masterbatch are respectively placed into corresponding feeding ports, and after being extruded by respective screws, the waterproof board is prepared by compounding after embossing roll calendering.

[0106] 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 head include 220℃; the vacuum degree is -0.06MPa; and 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 head include 220℃; and the vacuum degree is -0.08MPa.

[0107] Example 3

[0108] 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 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;

[0109] The raw material of the upper layer is composed of the following components in parts by weight: high-density polyethylene 40 parts (Ningxia Baofeng 5502S), chlorinated polypropylene 10 parts, metallocene polyethylene 15 parts (mLLDPE 3518PA / Exxon Mobil), carbon nanotubes 1 part (prepared in Preparation Example 6), nano calcium carbonate 5 parts (prepared in Preparation Example 3), polyethylene wax 1 part, antioxidant 3 parts (antioxidant MK-608), and ultraviolet resistance agent 1 part (ultraviolet resistance agent UV-531). The preparation method of the chlorinated polypropylene includes the following steps: polypropylene is soaked in o-xylene (the amount of polypropylene to o-xylene is 1g:8mL) at 135℃, 10% of the weight of the polypropylene is added as a modifier under stirring, reacted at 120℃ for 2.5h, alcohol precipitated, washed with water, and then vacuum dried at 60℃. The modifier is isopropyl trichloroacetate and tert-butyl peroxide in a mass ratio of 1:1.

[0110] 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-cut fiber 10 parts, antioxidant 1 part (antioxidant MK-608), and ultraviolet resistance agent 3 parts (ultraviolet resistance agent UV-531).

[0111] The preparation method of the waterproof board with high compressive strength and tensile strength includes the following steps:

[0112] 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, upper layer master batches and lower layer master batches are prepared;

[0113] S2. The middle layer raw materials are extruded and granulated by a double screw granulator, aramid short fibers are added from the side feeding port, and other raw materials are added from the main feeding port. After extrusion by the screw, drawing, and granulation, the middle layer master batch is prepared;

[0114] S3. The upper layer master batch, the middle layer master batch, and the lower layer master batch are respectively placed into the corresponding feeding ports by using a three-layer composite sheet extruder. After extrusion by the respective screws, the composite sheet is prepared by calendering through the concave-convex roller and then compounding.

[0115] 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 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 head include 220℃. The vacuum degree is -0.08MPa.

[0116] Example 4

[0117] A waterproof board with high compressive strength and tensile strength is prepared by compounding 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). The raw materials of the upper layer and the lower layer are the same.

[0118] The raw materials of the upper layer are 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.

[0119] The raw materials of the middle layer are 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 fibers 10 parts, antioxidant 1 part (antioxidant 168), and ultraviolet resistance agent 3 parts (ultraviolet resistance agent UV-328).

[0120] The preparation method of the waterproof board with high compressive strength and tensile strength includes the following steps:

[0121] S1. The upper and lower layers of raw materials are extruded and granulated by a double-screw granulator. After extrusion, drawing and granulation by the screw, the upper-layer master batch and the lower-layer master batch are prepared.

[0122] S2. The middle-layer raw materials are extruded and granulated by a double-screw granulator. The aramid short-cut fiber is added from the side feeding port, and other raw materials are added from the main feeding port. After extrusion, drawing and granulation by the screw, the middle-layer master batch is prepared.

[0123] 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. After extrusion by the respective screws and calendering by the concave-convex roller, the waterproof board is prepared.

[0124] 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 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 is 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃ and 220℃. The temperature conditions of the head include 220℃. The vacuum degree is -0.08MPa.

[0125] Example 5

[0126] 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 layer, the middle layer and the lower layer are 0.6mm, 0.8mm and 0.6mm respectively, and the total thickness is 2mm). The raw materials of the upper layer and the lower layer are the same.

[0127] The raw materials of the upper layer are 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.

[0128] The raw materials of the middle layer are 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-cut fiber 8 parts, antioxidant 2 parts (antioxidant 1010), and ultraviolet resistance agent 2 parts (ultraviolet resistance agent UV-327).

[0129] The preparation method of the waterproof plate with high compressive strength and tensile strength comprises the following steps:

[0130] S1. The upper and lower layers of raw materials 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;

[0131] S2. The middle-layer raw materials are extruded and granulated by a double-screw granulator, and after screw extrusion, drawing, and granulation, the middle-layer master batch is prepared.

[0132] S3. The upper-layer master batch, the middle-layer master batch, and the lower-layer master batch are respectively placed into corresponding feeding ports of a three-layer composite sheet extruder, and after being extruded by respective screws and being compounded after calendering by concave-convex rollers, the waterproof plate is prepared.

[0133] The temperature conditions of each zone of the double-screw granulator include 175℃, 185℃, 190℃, 205℃, 210℃, 220℃, 220℃, and 220℃, the temperature condition of the head includes 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 condition of the head includes 220℃, and the vacuum degree is -0.08MPa.

[0134] Comparative Example 1

[0135] 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 plate has a thickness of 2mm.

[0136] The preparation method of the waterproof plate comprises the following steps:

[0137] S1. The upper-layer raw material is extruded and granulated by a double-screw granulator, and after screw extrusion, drawing, and granulation, the master batch is prepared.

[0138] S2. The master batch is respectively placed into corresponding feeding ports of a sheet extruder, and after being extruded by a screw, the waterproof plate is prepared after being compounded after calendering by concave-convex rollers.

[0139] 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 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 condition of the head includes: 220℃; the vacuum degree is: -0.08MPa.

[0140] Comparative Example 2

[0141] 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.

[0142] The preparation method of the waterproof board includes the following steps:

[0143] 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;

[0144] 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.

[0145] 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 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 condition of the head includes: 220℃; the vacuum degree is: -0.08MPa.

[0146] Comparative Example 3

[0147] 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:

[0148] First, the nano calcium carbonate is dried at 90℃ for 3 hours to remove water, and then put into a high-speed mixer. The silane coupling agent KH-550 is weighed at 1% of the mass of the calcium carbonate, and then mixed with 4 times the mass of the nano calcium carbonate in anhydrous ethanol. Then the mixed solution and the nano calcium carbonate are mixed and stirred at 100℃ and 800rpm for 40min, and then dried to obtain modified nano calcium carbonate.

[0149] Comparative Example 4

[0150] The difference compared with Example 1 is only that the nano calcium carbonate is modified by polyethylene glycol. The specific steps are as follows:

[0151] First, the nano calcium carbonate is dried at 90°C for 3 hours to remove water, and then put into a high-speed mixer after cooling. The nano calcium carbonate is mixed with 4 times the mass of anhydrous ethanol, and stirred at 100°C and 800 rpm for 40 min. Then 2% of the mass of the nano calcium carbonate is added to the polyethylene glycol (molecular weight 1000), and the stirring is continued for 25 min at a stirring rate of 800 rpm. After drying, the modified nano calcium carbonate is obtained.

[0152] Comparative Example 5

[0153] The difference compared with Example 1 is only that the nano calcium carbonate is not modified.

[0154] Comparative Example 6

[0155] The difference compared with Example 1 is only that the carbon nanotubes are not modified.

[0156] Comparative Example 7

[0157] The difference compared with Example 1 is only 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).

[0158] Comparative Example 8

[0159] The difference compared with Example 1 is only 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 includes the following steps: polypropylene is soaked in o-xylene (the amount of polypropylene to o-xylene is 1g:10mL) at 125°C, 9% of the weight of the polypropylene is added to the modifier under stirring, and reacted at 130°C for 2h, then alcohol is precipitated, washed with water, and dried at 60°C under vacuum. The modifier is a mixture of isopropyl trichloroacetate and tert-butyl peroxide with a mass ratio of 1:1.

[0160] Comparative Example 9

[0161] Compared with Example 1, the only difference is that the metallocene polyethylene is not used in the middle layer, 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).

[0162] Effect Example: Mechanical property test

[0163] The waterproof and drainage plates obtained by the examples and comparative examples are respectively subjected to compression strength, tensile strength, elongation at break, tear strength and puncture strength tests, and the mechanical property test results are shown in Table 1.

[0164] The performance test indicators and methods are as follows:

[0165] The determination of the compression strength is in accordance with QCR562.3-2018.

[0166] Tensile strength, elongation at break: The determination of the tensile properties is in accordance with the provisions of GB / T 1040.2, the tensile speed is (250±50) mm / min, and the specific value is 250 mm / min.

[0167] Tear strength: The determination of the tear strength is in accordance with GB / T 529 without notched right-angle sample, the tensile speed is (250±50) mm / min, and the specific value is 250 mm / min.

[0168] Puncture strength: The determination of the puncture strength is in accordance with the provisions of national standard QCR562.3-2018.

[0169] Table 1

[0170]

[0171] The temperature range of a certain tunnel throughout the year is -20℃~35℃, and the humidity range is 30%~50%. The compression strength test conditions of the waterproof and drainage plate are set at humidity 30% and temperature -20℃, and humidity 50% and temperature 35℃, respectively. After 3 months, the compression strength of Examples 1-5 can still remain relatively stable (attenuation <5%), which can ensure long-term use effect, while the compression strength of Comparative Examples 1-2 attenuates >5% after 3 months.

[0172] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A waterproofing sheet having high compressive strength and tensile strength, characterized by, The upper layer, the middle layer and the lower layer are compounded, 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, modified carbon nanotube 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; The preparation method of the chlorinated polypropylene comprises the following steps: polypropylene is soaked in a solvent at 120-135℃, 8-10% of the weight of the polypropylene is added as a modifier under stirring, and the mixture is reacted at 120-135℃ for 1.5-2.5h, then alcohol precipitation, water washing and drying are performed, and the chlorinated polypropylene is obtained, wherein the modifier is a mixture of isopropyl trichloroacetate and tert-butyl peroxide in a mass ratio of 1:1; The modification of the modified carbon nanotube comprises the following steps: S1, the carbon nanotube is pretreated by acid treatment, washed and dried to obtain pretreated carbon nanotube; S2, the silane coupling agent KH-550 is mixed with an ethanol aqueous 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 and the silane solution are mixed in a ratio of 0.5-1g:100mL, ultrasonic dispersion is performed, and then refluxing is performed at 50-90℃ for 2-6h, followed by centrifugal washing and drying to obtain the modified carbon nanotube.

2. The waterproof sheet according to claim 1, wherein the waterproof sheet has high compressive strength and tensile strength. The method for modifying the nano calcium carbonate by silane coupling agent and polyethylene glycol comprises the following steps: 0.5%-2% of the silane coupling agent KH-550 is weighed according to the mass of the nano calcium carbonate, 3-5 times the mass 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, stirring is performed at 80-120℃ and a speed of 500-1000rpm for 30-60min, 1%-3% of the mass of the nano calcium carbonate of polyethylene glycol is then added, and the stirring is continued for 20-30min at a speed of 500-1000rpm, and then drying is performed.

3. The waterproof sheet having high compressive strength and tensile strength according to claim 2, wherein The molecular weight of the polyethylene glycol is 400-2000.

4. The waterproof sheet having high compressive strength and tensile strength according to claim 1, wherein The antioxidant is selected from antioxidant 1010 or antioxidant 168.

5. The waterproof sheet having high compressive strength and tensile strength according to claim 1, wherein The ultraviolet inhibitor is selected from one or more of ultraviolet inhibitor UV-531, ultraviolet inhibitor UV-327 and ultraviolet inhibitor UV-328.

6. The method for manufacturing a waterproofing sheet having high compressive strength and tensile strength according to any one of claims 1 to 5, wherein The method comprises the following steps: S1. The raw materials of the upper layer and the lower layer 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 middle layer raw material is extruded and granulated by a double screw granulator, aramid short fibers are added from a side feeding port, and other raw materials are added from a main feeding port. 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 placed into corresponding feeding ports by using a three-layer composite sheet extruder. After extrusion by respective screws, the composite is prepared by calendering through concave-convex rollers to prepare the waterproof drainage board.

7. Application of the waterproof drainage board with high compressive strength and tensile strength according to any one of claims 1-5 in a railway tunnel.

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