Polyethylene composite polypropylene laminated tire body waterproofing membrane with physical root blocking function

Abstract

The present application relates to waterproofing membrane technical field, and disclose a kind of polyethylene composite polypropylene laminated carcass waterproofing membrane with physical root resistance function, by upper and lower modified polyethylene separation layer, modified bitumen coating layer, composite laminated carcass is formed by double-roller pressurization.The composite carcass is made of high-temperature-resistant polypropylene film and phosphorus-containing silane modified calcium sulfate whisker reinforced modified PE film composite;Modified bitumen is compounded with two kinds of maleic anhydride grafts, realize double-membrane interface firm bonding, eliminate interlayer gap.Modified calcium sulfate whisker forms three-dimensional reinforcing framework, significantly improves the puncture resistance and tear resistance of the membrane, relies on double-layer high molecular film to realize pure physical root resistance, no chemical root inhibitor pollution soil, time decay problem;The present application does not need metal base, avoids corrosion failure, and has excellent mechanical, adhesive, heat and low temperature resistance, no root penetration in root puncture test, suitable for various planting roof long-acting waterproofing root resistance engineering.

Description

Technical Field

[0001] The present invention relates to the technical field of waterproofing membranes, in particular to a polyethylene composite polypropylene laminated reinforcement waterproofing membrane with physical root-resisting function. Background Art

[0002] With the continuous advancement of urban greening construction, the application scenarios of planted roofs have been continuously expanded, and the industry's requirements for comprehensive properties such as root puncture resistance, high temperature resistance, mechanical strength, environmental protection, safety and comprehensive economy of waterproofing membranes for planted roofs have been continuously increased. Currently, the mainstream root puncture-resistant waterproofing membranes on the market are mainly divided into two systems: chemical root-resisting type and physical root-resisting type. Both types of products have significant technical defects and it is difficult to meet the long-term engineering application requirements:

[0003] The first one is chemical root-resisting waterproofing membrane, which achieves the root-resisting effect by adding organic or inorganic chemical root-resisting inhibitors into the asphalt matrix. Long-term engineering application and test verification show that the chemical inhibitors will gradually lose with rain erosion, asphalt aging and soil microbial erosion, the root-resisting efficacy of the membrane will be greatly attenuated in the middle and late service period, and the long-term root-resisting effectiveness cannot be guaranteed; meanwhile, the precipitated chemical agents will penetrate into the planting soil layer, causing ecological environment risks of polluting soil and affecting the normal growth of vegetation, which does not conform to the low-carbon environmental protection development orientation of green buildings and sponge cities.

[0004] The second one is physical root-resisting waterproofing membrane. The existing schemes are subdivided into two routes: metal-based reinforcement and single polymer dense membrane, each with prominent shortcomings: metal-based root-resisting membranes often use copper reinforcement as the physical barrier layer, the procurement cost of metal raw materials is high, which greatly increases the engineering cost of the membrane; moreover, the metal reinforcement is prone to electrochemical corrosion after contacting with asphalt, polymer materials and soil moisture, and the reinforcement will rust and perforate after long-term service, losing both root-resisting and waterproofing functions, so the service life is limited. The single polymer dense membrane root-resisting membrane only relies on a single-layer polymer film to achieve root resistance. Limited by the molecular structure of a single material, it cannot simultaneously meet the multiple requirements of high tensile strength, high temperature dimensional stability and low-cost production. The film is prone to softening and creep under high temperature environment, and the risk of root puncture increases; if the film thickness is simply increased to enhance heat resistance and strength, it will significantly increase the raw material cost and the self-weight of the membrane, and the construction adaptability will decrease.

[0005] The structural design of existing polymer composite waterproofing membranes (such as polyethylene polypropylene membranes) only focuses on basic waterproofing performance and base bonding effect, and does not carry out the collaborative matching design of multi-layer structure with ultra-thin high strength and high temperature resistant physical root resistance for the harsh working conditions of planted roofs. Ordinary polyethylene and polypropylene single-layer films have insufficient heat resistance, and are prone to shrinkage and damage during high-temperature asphalt coating processing; the two polymer materials have poor interfacial compatibility with modified asphalt, and delamination and peeling are prone to occur between layers, making it difficult to form a stable and continuous physical barrier, and cannot stably achieve long-acting physical root resistance.

[0006] In view of the technical pain points of the existing technology, such as long-term root barrier failure, environmental hazards, high cost, imbalance between heat resistance and mechanical properties, and insufficient bonding strength of multi-layer interfaces, this application proposes a high-strength polyethylene composite polypropylene laminated waterproof membrane with physical root barrier function to solve the above technical problems. Summary of the Invention

[0007] (a) Technical problems to be solved

[0008] To address the shortcomings of existing technologies, this invention provides a polyethylene-polypropylene composite waterproof membrane with physical root-barrier function. This invention uses a polyethylene film and a Toray NO-135 high-temperature resistant polypropylene film to form a specialized root-barrier matrix, combined with a modified bitumen coating system adapted to a two-component graft modifier. Through a multi-layer synergistic structural design, it completely eliminates chemical root-barrier agents, relying on a dense polymer composite film to form a purely physical barrier layer. This achieves a balance of ultra-thin and lightweight construction, high tensile strength, high-temperature stability, high interlayer bonding strength, and controllable production costs, solving various inherent defects of traditional root-barrier membranes and providing a long-lasting, environmentally friendly, and cost-effective root-penetration resistant waterproofing solution for green roofs.

[0009] (II) Technical Solution

[0010] A polyethylene composite polypropylene laminated waterproof membrane with physical root barrier function includes a composite laminated body, wherein the composite laminated body is made of modified polyethylene film and high-temperature resistant polypropylene film bonded together by modified asphalt adhesive.

[0011] Preferably, the composite tire carcass consists of, from top to bottom, a polypropylene film, a modified asphalt compound, and a modified polyethylene film.

[0012] Preferably, the waterproof membrane has a multi-layer structure, consisting of an upper surface isolation layer, an upper modified bitumen coating layer, a composite composite matrix, a lower modified bitumen coating layer, and a lower surface isolation layer. The multi-layer structure is prepared by applying pressure with two rollers to obtain the waterproof membrane.

[0013] Preferably, both the upper and lower surface isolation layers are modified polyethylene films with a thickness of 0.08-0.12 mm. The modified polyethylene film is mainly composed of modified calcium sulfate whiskers grafted into polyethylene under the initiation of DCP.

[0014] Preferably, the modified asphalt coating layer is a modified asphalt binder, which is a mixture of asphalt, SBS, maleic anhydride-grafted polypropylene, and maleic anhydride-grafted polyethylene. SBS is an asphalt elastic modifier that can improve the toughness, cohesion, and wettability of asphalt with polymer films.

[0015] Preferably, the method for preparing the composite laminated tire includes the following steps: uniformly coating a layer of modified asphalt rubber on a high-temperature resistant polypropylene film, then covering it with a modified polyethylene film, pressing it with two rollers, and cooling it to obtain the composite laminated tire; the high-temperature resistant polypropylene film is of the Toray NO-135 type.

[0016] Preferably, the method for preparing the modified asphalt coating layer includes the following steps:

[0017] Heat the asphalt to 160-170℃, add SBS and shear disperse for 1-2 hours, then add maleic anhydride-grafted polypropylene and maleic anhydride-grafted polyethylene, stir for 30-50 minutes to obtain the modified asphalt coating layer.

[0018] Preferably, the mass ratio of the asphalt, SBS, maleic anhydride-grafted polypropylene, and maleic anhydride-grafted polyethylene is 100:6-10:1-3:1-3.

[0019] Preferably, the method for preparing the modified polyethylene film includes the following steps:

[0020] (1) Disperse trimethylolphosphine oxide and p-hydroxyanisole in DMF, stir to disperse, then add itaconic acid, heat to 90-100℃, stir to react for 4-6 hours. After the reaction is completed, cool to room temperature, wash with deionized water, and dry to obtain the intermediate. In this reaction, trimethylolphosphine oxide and itaconic acid are used as raw materials, and p-hydroxyanisole is used as a polymerization inhibitor. The intermediate is obtained through ring-opening reaction. The reaction synthesis route is as follows:

[0021] ;

[0022] (2) The intermediate, p-hydroxyanisole, and tetrabutylammonium bromide were dispersed in DMF, and then γ-glycidoxypropyltrimethoxysilane was added. The temperature was raised to 110-115℃ and the reaction was carried out for 10-12 h. After the reaction was completed, the mixture was rotary evaporated and dried to obtain a phosphorus-containing silane. In this reaction, p-hydroxyanisole was used as a polymerization inhibitor and tetrabutylammonium bromide was used as a catalyst. The intermediate and γ-glycidoxypropyltrimethoxysilane were reacted through a ring-opening reaction to obtain the phosphorus-containing silane. The reaction synthesis route is as follows:

[0023] ;

[0024] (3) Disperse the phosphorus-containing silane in a 90% ethanol aqueous solution, adjust the pH to 3-4 with acetic acid, add hydroxylated calcium sulfate whiskers, heat to 80℃, stir for 4-5 hours, wash with ethanol after the reaction is complete, and dry to obtain modified calcium sulfate whiskers. In this reaction, the phosphorus-containing silane is hydrolyzed and hydroxylated calcium sulfate whiskers are condensed to obtain modified calcium sulfate whiskers.

[0025] (4) After mixing low-density polyethylene, high-density polyethylene, metallocene polyethylene, modified calcium sulfate whiskers, dicumyl peroxide (DCP), and antioxidant evenly, the mixture is first dried in an oven at 40-50℃, then added to a twin-screw extruder for granulation, and finally placed in a film casting machine to control the film thickness to 0.09-0.14 mm to prepare a modified polyethylene film.

[0026] Preferably, in (1), the mass ratio of trihydroxymethylphosphoric acid to itaconic acid is 1:2.4-3.

[0027] Preferably, in step (2), the mass ratio of the intermediate to γ-glycidoxypropyltrimethoxysilane is 1:1.5-1.8.

[0028] Preferably, in step (3), the mass ratio of phosphorus-containing silane to hydroxylated calcium sulfate whiskers is 0.05-0.1:1.

[0029] Preferably, in step (4), the mass ratio of low-density polyethylene, high-density polyethylene, metallocene polyethylene, modified calcium sulfate whiskers, DCP, and antioxidant is 100:5-10:10-15:1-5:0.4-1:0.5-1.

[0030] Preferably, in step (4), the temperature of the twin-screw extruder is 190°C and the screw speed is 100 r / min; the processing temperature of the film casting machine is 190°C and the screw speed is 50 r / min.

[0031] (iii) Beneficial technical effects

[0032] In the preparation of modified polyethylene film, this application uses low-density polyethylene, high-density polyethylene, metallocene polyethylene, and modified calcium sulfate whiskers as raw materials, and DCP as an initiator to graft modified calcium sulfate whiskers into polyethylene. Because the modified calcium sulfate whiskers contain triene groups, there are more entanglements and connection points between molecular chains, resulting in a more continuous and dense three-dimensional network. This significantly improves the tensile strength, tear resistance, creep resistance, and environmental stress cracking resistance of the film, making it more difficult for roots to penetrate mechanically. Furthermore, the modified polyethylene film is filled with phosphorus-containing calcium sulfate whiskers, which form a three-dimensional reinforcing skeleton within the polyethylene matrix, significantly improving the film's tear resistance, puncture resistance, and burst resistance. Specifically, when fine lateral roots and capillary roots continuously puncture and compress, the calcium sulfate whiskers can disperse localized stress concentration in the root system, preventing pinholes and microcracks in the film. Simultaneously, polyethylene itself has excellent toughness, which can buffer the impact of soil settlement and lateral root growth, compensating for the brittleness and susceptibility to cracking of polypropylene films.

[0033] The modified calcium sulfate whiskers prepared in this application contain phosphorus, which can play a flame-retardant role. Specifically, when heated at high temperatures, the phosphorus component forms a flame-retardant carbon layer to isolate oxygen and heat, inhibiting the melting and dripping of the film and the spread of flames. Combined with the high temperature resistance and non-flammability of the calcium sulfate whiskers themselves, the polyethylene substrate in the upper and lower surface isolation layers and the laminated matrix all have excellent flame-retardant capabilities, solving the defects of ordinary polyethylene films that are flammable and easily melt and break at high temperatures, and making them suitable for high-temperature construction of green roofs and the requirements of roof fire protection conditions.

[0034] This application combines maleic anhydride-grafted polypropylene and maleic anhydride-grafted polyethylene as graft modifiers in a modified asphalt system. Maleic anhydride-grafted polyethylene has a similar molecular structure to modified polyethylene film, enabling compatibility and fusion between the polyethylene film and asphalt. Maleic anhydride-grafted polypropylene has excellent interfacial compatibility with high-temperature resistant polypropylene film. The synergistic effect of the two grafting components allows the modified asphalt compound to simultaneously possess excellent wetting and bonding capabilities to both polyethylene film and high-temperature resistant polypropylene film. This ensures that the two layers of the polyethylene / polypropylene laminated carcass are tightly bonded without gaps, forming a continuous and dense double-layer high-molecular physical barrier layer. This prevents roots from penetrating along the interlayer gaps, stably achieving pure physical root barrier without the need for chemical root barrier inhibitors, and eliminating the risk of soil pollution and root barrier effect degradation. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall cross-sectional structure of the waterproof membrane of the present invention. Detailed Implementation

[0036] Unless otherwise specified, all materials and reagents used in the following examples are commercially available. Experimental methods not specifically described in the examples are generally performed under standard conditions or as recommended by the manufacturer.

[0037] The preparation method of hydroxylated calcium sulfate whiskers includes the following steps: sodium hydroxide, sodium sulfate, and deionized water are added to a flask, stirred and dispersed, and the concentrations of the sodium hydroxide aqueous solution and the sodium sulfate aqueous solution are controlled to be 0.1 mol / L and 0.1 mol / L, respectively. After stirring and mixing evenly, 10 g of calcium sulfate whiskers are added, and the mixture is stirred and reacted at room temperature for 4 h. After the reaction is completed, the mixture is filtered, washed with deionized water, and dried to obtain hydroxylated calcium sulfate whiskers.

[0038] Example 1

[0039] This embodiment provides a method for preparing a composite laminated carcass, including the following steps:

[0040] (1) Disperse 14g of trihydroxymethyl phosphorus oxide and 0.05g of p-hydroxyanisole into DMF, stir and disperse, then add 35g of itaconic acid, heat to 90℃, stir and react for 6h, after the reaction is completed, cool to room temperature, wash with deionized water, dry, and obtain intermediate.

[0041] (2) Disperse 10g of intermediate, 0.025g of p-hydroxyanisole and 0.25g of tetrabutylammonium bromide into DMF, then add 16g of γ-glycidoxypropyltrimethoxysilane, heat to 110℃, react for 12h, after the reaction is completed, rotary evaporate and dry to obtain phosphorus-containing silane.

[0042] (3) Disperse 1g of phosphorus-containing silane in a 90% ethanol aqueous solution, adjust the pH to 4 with acetic acid, add 20g of hydroxylated calcium sulfate whiskers, heat to 80℃, stir for 5h, wash with ethanol after the reaction is complete, and dry to obtain modified calcium sulfate whiskers.

[0043] (4) Mix 100g of low-density polyethylene, 5g of high-density polyethylene, 10g of metallocene polyethylene, 1g of modified calcium sulfate whiskers, 0.4g of DCP, and 0.5g of antioxidant 1010 evenly, dry them in an oven at 40℃, and then add them to a twin-screw extruder for granulation. Set the temperature of the twin-screw extruder to 190℃ and the screw speed to 100r / min. Finally, put them into a film casting machine. Set the processing temperature of the film casting machine to 190℃ and the screw speed to 50r / min. Control the film thickness to 0.09mm to prepare a modified polyethylene film.

[0044] (5) Heat 100g of asphalt to 160℃, add 6g of SBS shear dispersion for 2h, then add 1g of maleic anhydride grafted polypropylene and 1g of maleic anhydride grafted polyethylene, stir for 30min to obtain modified asphalt rubber.

[0045] (6) The preparation method of the composite composite tire body includes the following steps: a layer of modified asphalt rubber is uniformly coated on a high-temperature resistant polypropylene film (thickness is 0.04mm), and then a modified polyethylene film is laid on it. After being pressed by two rollers and cooled, the thickness of the tire body is controlled to be 4mm to obtain the composite composite tire body.

[0046] Example 2

[0047] This embodiment provides a method for preparing a composite laminated carcass, including the following steps:

[0048] (1) 14g of trihydroxymethyl phosphorus oxide and 0.054g of p-hydroxyanisole were dispersed in DMF and stirred. Then 40g of itaconic acid was added to it, the temperature was raised to 95℃, and the reaction was stirred for 6h. After the reaction was completed, the mixture was cooled to room temperature, washed with deionized water, and dried to obtain the intermediate.

[0049] (2) Disperse 10g of intermediate, 0.028g of p-hydroxyanisole and 0.3g of tetrabutylammonium bromide into DMF, then add 18g of γ-glycidoxypropyltrimethoxysilane, heat to 115℃, react for 10h, after the reaction is completed, rotary evaporate and dry to obtain phosphorus-containing silane.

[0050] (3) Disperse 1.5g of phosphorus-containing silane in a 90% ethanol aqueous solution, adjust the pH to 4 with acetic acid, add 20g of hydroxylated calcium sulfate whiskers, heat to 80℃, stir for 4h, wash with ethanol after the reaction is complete, and dry to obtain modified calcium sulfate whiskers.

[0051] (4) Mix 100g of low-density polyethylene, 8g of high-density polyethylene, 13g of metallocene polyethylene, 3g of modified calcium sulfate whiskers, 0.6g of DCP, and 0.8g of antioxidant 1010 evenly, dry them in an oven at 40℃, and then add them to a twin-screw extruder for granulation. Set the temperature of the twin-screw extruder to 190℃ and the screw speed to 100r / min. Finally, put them into a film casting machine. Set the processing temperature of the film casting machine to 190℃ and the screw speed to 50r / min. Control the film thickness to 0.1mm to prepare a modified polyethylene film.

[0052] (5) Heat 100g of asphalt to 160℃, add 8g of SBS shear dispersion for 1h, then add 2g of maleic anhydride-grafted polypropylene and 2g of maleic anhydride-grafted polyethylene, stir for 50min to obtain modified asphalt rubber.

[0053] (6) The preparation method of the composite composite tire body includes the following steps: a layer of modified asphalt rubber is uniformly coated on a high-temperature resistant polypropylene film (thickness is 0.04mm), and then a modified polyethylene film is laid on it. After being pressed by two rollers and cooled, the thickness of the tire body is controlled to be 4mm to obtain the composite composite tire body.

[0054] Example 3

[0055] This embodiment provides a method for preparing a composite laminated carcass, including the following steps:

[0056] (1) 14g of trihydroxymethyl phosphorus oxide and 0.055g of p-hydroxyanisole were dispersed in DMF and stirred to disperse. Then 42g of itaconic acid was added to it, the temperature was raised to 100℃, and the reaction was stirred for 4h. After the reaction was completed, it was cooled to room temperature, washed with deionized water, and dried to obtain the intermediate.

[0057] (2) Disperse 10g of intermediate, 0.026g of p-hydroxyanisole and 0.25g of tetrabutylammonium bromide into DMF, then add 16g of γ-glycidoxypropyltrimethoxysilane, heat to 110℃, react for 12h, after the reaction is completed, rotary evaporate and dry to obtain phosphorus-containing silane.

[0058] (3) Disperse 2g of phosphorus-containing silane in a 90% ethanol aqueous solution, adjust the pH to 3 with acetic acid, add 20g of hydroxylated calcium sulfate whiskers, heat to 80℃, stir for 5h, wash with ethanol after the reaction is complete, and dry to obtain modified calcium sulfate whiskers.

[0059] (4) Mix 100g of low-density polyethylene, 10g of high-density polyethylene, 15g of metallocene polyethylene, 5g of modified calcium sulfate whiskers, 1g of DCP, and 1g of antioxidant 1010 evenly, dry them in an oven at 40℃, and then add them to a twin-screw extruder for granulation. Set the temperature of the twin-screw extruder to 190℃ and the screw speed to 100r / min. Finally, put them into a film casting machine. Set the processing temperature of the film casting machine to 190℃ and the screw speed to 50r / min. Control the film thickness to 0.14mm to prepare a modified polyethylene film.

[0060] (5) Heat 100g of asphalt to 170℃, add 10g of SBS shear dispersion for 2h, then add 3g of maleic anhydride-grafted polypropylene and 3g of maleic anhydride-grafted polyethylene, stir for 30min to obtain modified asphalt rubber.

[0061] (6) The preparation method of the composite composite tire body includes the following steps: a layer of modified asphalt rubber is uniformly coated on a high-temperature resistant polypropylene film (thickness is 0.04mm), and then a modified polyethylene film is laid on it. After being pressed by two rollers and cooled, the thickness of the tire body is controlled to be 4mm to obtain the composite composite tire body.

[0062] Comparative Example 1

[0063] The method of preparing the composite matrix in this comparative example is roughly the same as that in Example 1, except that in step (4), calcium sulfate whiskers are used instead of modified calcium sulfate whiskers.

[0064] Comparative Example 2

[0065] The method of preparing the composite matrix in this comparative example is roughly the same as that in Example 1, except that in step (4), phosphorus-containing silane is used instead of modified calcium sulfate whiskers.

[0066] Comparative Example 3

[0067] The method of preparing the composite composite carcass in this comparative example is roughly the same as that in Example 1, except that in step (5), polypropylene and polyethylene are used instead of maleic anhydride-grafted polypropylene and maleic anhydride-grafted polyethylene.

[0068] Comparative Example 4

[0069] The method of preparing the composite composite carcass in this comparative example is roughly the same as that in Example 1, except that step (5) does not contain maleic anhydride-grafted polypropylene or maleic anhydride-grafted polyethylene.

[0070] According to GB / T328.8-2007, test the longitudinal tensile strength and longitudinal elongation;

[0071] According to GB / T 328.14-2007, low-temperature flexibility was tested;

[0072] Heat resistance was tested according to GB / T 328.11-2007;

[0073] According to GB / T 328.20-2017, the peel strength of the joint was tested;

[0074] According to GB / T 1741-2007, resistance to mold corrosion was tested;

[0075] Flame retardant performance was tested in accordance with GB 8624-2012.

[0076] The composite tire carcasses prepared in the above embodiments and comparative examples were subjected to performance tests, and the test results are shown in the table below:

[0077] Table 1:

[0078] Longitudinal tensile force (N / 50mm) Longitudinal elongation (%) Low-temperature flexibility (no cracks at -20℃) Heat resistance (does not drip at 90℃) Seam peel strength (N / mm) Resistance to mold and corrosion Flame retardant rating Example 1 680 170 qualified qualified 2.0 Level 1 B1 Example 2 780 189 qualified qualified 2.3 Level 1 B1 Example 3 810 213 qualified qualified 2.5 Level 0 B1 Comparative Example 1 460 138 Unqualified Unqualified 1.2 Level 4 B3 Comparative Example 2 530 143 qualified qualified 1.8 Level 2 B2 Comparative Example 3 600 150 qualified qualified 1.6 Level 2 B1 Comparative Example 4 550 145 qualified qualified 1.4 Level 3 B1

[0079] As can be seen from the table, the composite laminated carcass prepared by this invention has excellent comprehensive performance.

[0080] Comparative Example 1 uses calcium sulfate whiskers instead of modified calcium sulfate whiskers, and its performance is worse than that of this embodiment. This is because unmodified calcium sulfate whiskers have poor compatibility in the organic matrix and serious agglomeration, which seriously affects the performance of the composite matrix.

[0081] Comparative Example 2 uses phosphorus-containing silane instead of modified calcium sulfate whiskers. Its mechanical properties are better than those of Comparative Example 1, but worse than those of the Example. This is because it does not contain calcium sulfate whiskers. Organically modified calcium sulfate whiskers have good compatibility with the organic matrix and can be uniformly dispersed in the organic matrix. When subjected to external stress, they can absorb and disperse stress, thereby improving the mechanical properties of the laminated matrix. However, Comparative Example 2 does not contain this structure, so its mechanical properties are worse than those of the Example.

[0082] The reason why Comparative Example 3 uses polypropylene and polyethylene instead of maleic anhydride-grafted polypropylene and maleic anhydride-grafted polyethylene and has poor mechanical properties is speculated to be that the hydroxyl groups contained in the modified polyethylene film can undergo ring-opening esterification reaction with the maleic anhydride groups in the modified asphalt to form a strong chemical bond. This interfacial covalent bond is far superior to physical blending. It can significantly improve the bonding strength between the asphalt layer and the film, effectively transfer and disperse stress, thereby hindering interfacial debonding and crack propagation, and ultimately enhancing the mechanical properties of the composite system. However, Comparative Example 3 does not contain maleic anhydride and cannot enhance the bonding performance between the interfaces, so its mechanical properties are poor.

[0083] like Figure 1 As shown, this roll material consists of, from top to bottom, an upper surface isolation layer, an upper modified bitumen coating layer, a composite composite matrix (including a polypropylene film, modified bitumen compound, and modified polyethylene film), a lower modified bitumen coating layer, and a lower surface isolation layer.

[0084] Example 4

[0085] This embodiment provides a polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function. The waterproof membrane has a multi-layered composite structure, and the entire membrane is formed by stacking the layers sequentially and then pressing them together using two rollers. The structure of each layer and the corresponding raw materials are shown below:

[0086] Table 2:

[0087] Layer structure name raw material upper surface isolation layer Modified polyethylene film prepared in Example 3 Modified asphalt coating layer Modified asphalt compound prepared in Example 3 Composite tire carcass The upper layer is a high-temperature resistant polypropylene film, the middle layer is the modified asphalt compound prepared in Example 3, and the lower layer is the modified polyethylene film prepared in Example 3. Lower modified bitumen coating layer Modified asphalt compound prepared in Example 3 Lower surface isolation layer Modified polyethylene film prepared in Example 3

[0088] Comparative Example 5

[0089] The process of preparing the waterproof membrane in this comparative example is largely the same as that in Example 4. The structure of each layer and the corresponding raw materials are shown below:

[0090] Table 3:

[0091] Layer structure name raw material upper surface isolation layer The modified polyethylene film prepared in Comparative Example 1 Modified asphalt coating layer Modified asphalt compound prepared in Comparative Example 1 Composite tire carcass The upper layer is a high-temperature resistant polypropylene film, the middle layer is the modified asphalt compound prepared in Comparative Example 1, and the lower layer is the modified polyethylene film prepared in Comparative Example 1. Lower modified bitumen coating layer Modified asphalt compound prepared in Comparative Example 1 Lower surface isolation layer The modified polyethylene film prepared in Comparative Example 1

[0092] Comparative Example 6

[0093] The process of preparing the waterproof membrane in this comparative example is largely the same as that in Example 4. The structure of each layer and the corresponding raw materials are shown below:

[0094] Table 4:

[0095] Layer structure name raw material upper surface isolation layer The modified polyethylene film prepared in Comparative Example 2 Modified asphalt coating layer Modified asphalt compound prepared in Comparative Example 2 Composite tire carcass The upper layer is a high-temperature resistant polypropylene film, the middle layer is the modified asphalt compound prepared in Comparative Example 2, and the lower layer is the modified polyethylene film prepared in Comparative Example 2. Lower modified bitumen coating layer Modified asphalt compound prepared in Comparative Example 2 Lower surface isolation layer The modified polyethylene film prepared in Comparative Example 2

[0096] Comparative Example 7

[0097] The process of preparing the waterproof membrane in this comparative example is largely the same as that in Example 4. The structure of each layer and the corresponding raw materials are shown below:

[0098] Table 5:

[0099] Layer structure name raw material upper surface isolation layer The modified polyethylene film prepared in Comparative Example 3 Modified asphalt coating layer Modified asphalt compound prepared in Comparative Example 3 Composite tire carcass The upper layer is a high-temperature resistant polypropylene film, the middle layer is the modified asphalt compound prepared in Comparative Example 3, and the lower layer is the modified polyethylene film prepared in Comparative Example 3. Lower modified bitumen coating layer Modified asphalt compound prepared in Comparative Example 3 Lower surface isolation layer The modified polyethylene film prepared in Comparative Example 3

[0100] Comparative Example 8

[0101] The process of preparing the waterproof membrane in this comparative example is largely the same as that in Example 4. The structure of each layer and the corresponding raw materials are shown below:

[0102] Table 6:

[0103] Layer structure name raw material upper surface isolation layer The modified polyethylene film prepared in Comparative Example 4 Modified asphalt coating layer Modified asphalt compound prepared in Comparative Example 4 Composite tire carcass The upper layer is a high-temperature resistant polypropylene film, the middle layer is the modified asphalt compound prepared in Comparative Example 4, and the lower layer is the modified polyethylene film prepared in Comparative Example 4. Lower modified bitumen coating layer Modified asphalt compound prepared in Comparative Example 4 Lower surface isolation layer The modified polyethylene film prepared in Comparative Example 4

[0104] Comparative Example 9

[0105] The process of preparing the waterproof membrane in this comparative example is largely the same as that in Example 4. The structure of each layer and the corresponding raw materials are shown below:

[0106] Table 7:

[0107] Layer structure name raw material upper surface isolation layer polyethylene film Modified asphalt coating layer asphalt Composite tire carcass The top layer is a polypropylene film, the middle layer is asphalt, and the bottom layer is a polyethylene film. Lower modified bitumen coating layer asphalt Lower surface isolation layer polyethylene film

[0108] Root resistance performance was tested according to GB / T35468-2017.

[0109] Table 8:

[0110] Root penetration resistance Example 4 No root penetration Comparative Example 5 The root system is extremely extensive, with numerous penetration points. Comparative Example 6 The root system is relatively small, with only a few penetration points. Comparative Example 7 With few roots, penetration points appeared. Comparative Example 8 With many roots, penetration points appear. Comparative Example 9 The root system is dense and penetrates a large area, with multiple tears, cracks, and interconnected holes in the roll material.

[0111] As shown in the table, the waterproof membrane prepared in this application has excellent root-barrier properties.

[0112] The reason why the waterproof membrane of Example 4 of this application has better performance than that of Comparative Example 9 is that the modified polyethylene film layer is provided on both the upper and lower surfaces of the membrane, and is also filled with calcium sulfate whiskers, which have dense and puncture-resistant properties. The upper isolation layer is in direct contact with the planting soil layer, which can first block shallow fine capillary roots and prevent fine roots from directly eroding the asphalt coating layer and creating micropores. The lower isolation layer isolates the sharp protrusions of the building base and cement mortar particles, preventing hard objects in the base layer from piercing the bottom layer of the membrane and preventing roots from invading from the damaged bottom layer. The upper and lower isolation layers are tightly bonded to the modified asphalt through chemical bonds and are connected with the root-blocking matrix in the middle to form an integral barrier system without breaks or weak areas. The membrane has no through weak areas from top to bottom and has root-blocking ability throughout the entire cross section.

[0113] In summary, this invention relies on a double-layered, dense polymer membrane to construct a purely physical root barrier, eliminating the need for chemical root-blocking agents and avoiding problems such as agent loss and soil pollution. The phosphorus element in the calcium sulfate whiskers endows the roll material with excellent flame-retardant properties, and the hydroxyl groups in the modified whiskers can undergo esterification with the maleic anhydride groups in the asphalt, forming covalent chemical bonds at the interfaces of each layer, completely eliminating interlayer gaps and preventing roots from puncturing along the interlayer. The bismaleic anhydride-grafted modified asphalt is compatible with both polyethylene and polypropylene membranes, ensuring a tight and gapless bond between the laminated bodies. The high-temperature resistant polypropylene film solves the high-temperature softening and creep defects of polyethylene, and the modified polyethylene film achieves high tear resistance and puncture resistance through whisker reinforcement. The complementary properties of the two membranes significantly improve the safety redundancy of root blocking. This invention eliminates the need for a metal substrate, avoids the risk of electrochemical corrosion, has controllable material costs, and produces lightweight and easy-to-install rolls. It also boasts comprehensive advantages such as flame retardancy, high temperature resistance, high mechanical strength, strong interlayer adhesion, long-lasting root barrier properties, and environmental friendliness. It effectively solves the technical defects of existing chemical root barrier rolls, such as poor long-term effectiveness and environmental pollution; metal-based root barrier rolls, such as high cost and easy corrosion; and single polymer membranes, such as difficulty in balancing heat resistance and strength. It is suitable for long-lasting waterproofing and root barrier projects for various types of green roofs.

[0114] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function, characterized in that, It includes a composite tire carcass, which is made of modified polyethylene film and high-temperature resistant polypropylene film bonded together by modified asphalt adhesive.

2. The polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function according to claim 1, characterized in that, The composite tire carcass consists of, from top to bottom, a polypropylene film, modified asphalt rubber compound, and a modified polyethylene film.

3. The polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function according to claim 1, characterized in that, The waterproof membrane has a multi-layer structure, consisting of an upper surface isolation layer, an upper modified bitumen coating layer, a composite composite matrix, a lower modified bitumen coating layer, and a lower surface isolation layer. The multi-layer structure is prepared by applying pressure with two rollers to obtain the waterproof membrane.

4. The polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function according to claim 1, characterized in that, Both the upper and lower surface isolation layers are modified polyethylene films. The modified polyethylene films are mainly composed of modified calcium sulfate whiskers grafted into polyethylene under the initiation of DCP.

5. The polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function according to claim 1, characterized in that, The modified asphalt coating layer is a modified asphalt adhesive, which is a mixture of asphalt, SBS, maleic anhydride-grafted polypropylene, and maleic anhydride-grafted polyethylene.

6. The polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function according to claim 1, characterized in that, The method for preparing the composite composite tire includes the following steps: uniformly coating a layer of modified asphalt rubber on a high-temperature resistant polypropylene film, then covering it with a modified polyethylene film, and then pressing and cooling it with two rollers to obtain the composite composite tire.

7. The polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function according to claim 1, characterized in that, The preparation method of the modified asphalt compound includes the following steps: Heat the asphalt to 160-170℃, add SBS and shear disperse for 1-2 hours, then add maleic anhydride-grafted polypropylene and maleic anhydride-grafted polyethylene, stir for 30-50 minutes to obtain modified asphalt rubber. The mass ratio of the asphalt, SBS, maleic anhydride-grafted polypropylene, and maleic anhydride-grafted polyethylene is 100:6-10:1-3:1-3.

8. The polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function according to claim 1, characterized in that, The method for preparing the modified polyethylene film includes the following steps: (1) Disperse trihydroxymethyl phosphorus oxide and p-hydroxyanisole in DMF, stir and disperse, then add itaconic acid, heat to 90-100℃, stir and react for 4-6 hours. After the reaction is completed, cool to room temperature, wash with deionized water, and dry to obtain an intermediate. The mass ratio of trihydroxymethyl phosphorus oxide to itaconic acid is 1:2.4-3. (2) Disperse the intermediate, p-hydroxyanisole, and tetrabutylammonium bromide in DMF, then add γ-glycidoxypropyltrimethoxysilane, heat to 110-115℃, react for 10-12 h, after the reaction is completed, rotary evaporate and dry to obtain phosphorus-containing silane, wherein the mass ratio of the intermediate to γ-glycidoxypropyltrimethoxysilane is 1:1.5-1.8; (3) Disperse the phosphorus-containing silane in a 90% ethanol aqueous solution, adjust the pH to 3-4 with acetic acid, add hydroxylated calcium sulfate whiskers, heat to 80℃, stir for 4-5 h, wash with ethanol after the reaction, dry to obtain modified calcium sulfate whiskers, the mass ratio of the phosphorus-containing silane to the hydroxylated calcium sulfate whiskers is 0.05-0.1:1; (4) After mixing low-density polyethylene, high-density polyethylene, metallocene polyethylene, modified calcium sulfate whiskers, DCP and antioxidant evenly, dry them in an oven at 40-45℃, then add them to a twin-screw extruder for granulation, and finally put them into a film casting machine to control the film thickness to 0.09-0.14mm to prepare modified polyethylene film.

9. The polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function according to claim 8, characterized in that, In (4), the mass ratio of low-density polyethylene, high-density polyethylene, metallocene polyethylene, modified calcium sulfate whiskers, DCP, and antioxidant is 100:5-10:10-15:1-5:0.4-1:0.5-1; in (4), the temperature of the twin-screw extruder is 190℃ and the screw speed is 100r / min; the processing temperature of the film casting molding machine is 190℃ and the screw speed is 50r / min.

10. The application of a polyethylene composite polypropylene laminated waterproof membrane with physical root-barrier function as described in any one of claims 1-9 in green roofs.

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