Environment-friendly biodegradable waterproofing membrane and preparation method thereof

Abstract

The application provides an environment-friendly biodegradable waterproof roll material and a preparation method thereof, and belongs to the field of waterproof roll materials. The roll material is designed to comprise multiple functional layers. First, high-toughness and degradable bio-based fibers and natural fibers are selected in the reinforcing layer to provide reliable mechanical properties and environmental protection properties. The waterproof functional layer adopts renewable bio-based polymers, which not only improves the adaptability of the material, but also enhances the mechanical properties by being combined with inorganic fillers; montmorillonite, bentonite and regenerated cellulose are introduced as fillers in this layer, and the synergistic effect of the three significantly improves the waterproof performance, high-temperature resistance and aging resistance, thereby prolonging the service life. The surface protection layer uses modified polyurethane combined with fluorinated polyurethane and silicone resin, thereby enhancing the hydrophobicity, anti-pollution property, heat resistance and ultraviolet resistance.

Description

Technical Field

[0001] This invention belongs to the field of waterproof membrane technology, and relates to an environmentally friendly biodegradable waterproof membrane and its preparation method. Background Technology

[0002] Waterproof membranes are an indispensable key material in the modern construction industry, widely used in roofs, basements, tunnels, and other building components requiring waterproofing. Their primary function is to prevent moisture from penetrating the structural layers of a building, thereby avoiding water damage, protecting the building's foundation and internal facilities, and extending the building's lifespan. The applications of waterproof membranes are extremely broad, covering residential, commercial, industrial, and infrastructure projects, and their role is particularly important in rainy, humid, or damp climates.

[0003] With increasingly severe global climate change and more frequent extreme weather events, the performance requirements for waterproof membranes in buildings are becoming increasingly stringent. Traditional waterproof materials, such as asphalt waterproof membranes, synthetic rubber waterproof membranes, and polyvinyl chloride (PVC) waterproof membranes, while offering good waterproofing, often rely on petroleum-based polymers as raw materials. The production of these materials often consumes significant amounts of energy and releases greenhouse gases and harmful substances, resulting in a substantial environmental burden. Furthermore, petroleum-based materials may gradually age due to external factors such as ultraviolet radiation, oxidation, and temperature changes, leading to a decline in waterproofing performance or even failure. Therefore, the use of traditional waterproof membranes not only poses environmental pollution problems but may also affect the long-term performance and sustainability of buildings.

[0004] Therefore, there is a need to develop an environmentally friendly biodegradable waterproof membrane to make up for the shortcomings of traditional waterproof membranes. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide an environmentally friendly biodegradable waterproof membrane and its preparation method. The environmentally friendly biodegradable waterproof membrane comprises multiple functional layers. By employing reinforcing layers of high-toughness, bio-based fibers and natural fibers, it provides excellent mechanical properties and environmental characteristics. The waterproof functional layer combines renewable bio-based polymers with inorganic fillers, significantly improving waterproof performance, high-temperature resistance, and aging resistance. The surface protective layer, through a combination of modified polyurethane, fluorinated polyurethane, and silicone resin, enhances hydrophobicity, stain resistance, heat resistance, and UV resistance.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides an environmentally friendly biodegradable waterproof membrane, the environmentally friendly biodegradable waterproof membrane comprising a reinforcing layer, a waterproof functional layer and a surface protective layer; wherein the reinforcing layer, the waterproof functional layer and the surface protective layer are stacked sequentially;

[0008] The reinforcing layer comprises bio-based fibers, natural fibers, binders, and hydrophobic modifiers;

[0009] The waterproof functional layer comprises a bio-based polymer, modified silica nanoparticles, modified fillers, toughening agents, and antioxidants.

[0010] The surface protective layer includes fluorinated polyurethane, silicone resin, fatty acid-coated reflective material, antioxidant, ultraviolet absorber, and hydrophobic modifier.

[0011] Bio-based fibers and natural fibers are selected as the main materials for the reinforcement layer: bio-based fibers have high toughness and biodegradability, while natural fibers provide excellent strength and durability. Through shearing, the fibers are processed into short fibers with a large specific surface area, which not only helps to achieve uniform dispersion in the solution but also significantly improves the wetting effect of the binder. The pretreated fibers provide a reliable mechanical property basis for the formation of the reinforcement layer, enabling it to serve as a high-strength and durable base for the roll material, significantly improving the tear resistance and deformation resistance of the roll material, while also endowing the roll material with environmentally friendly and biodegradable properties.

[0012] After the binder is dispersed in water, its active functional groups (such as hydroxyl and carboxyl groups) partially dissociate, enhancing its chemical activity and providing reaction sites for subsequent bonding between fibers. Through cross-linking, the binder not only significantly improves the tensile and deformation resistance of the reinforcing layer, but also enhances the overall structural stability, providing solid support for the waterproof functional layer and the surface protective layer.

[0013] During the bonding process with fibers, the adhesive forms an initial adhesion layer through hydrogen bonds, van der Waals forces, or covalent bonds (such as the reaction of carboxyl groups with hydroxyl groups on the fiber surface). Subsequently, long-chain alkyl or fluorinated groups in the hydrophobic modifier cover the fiber surface through physical adsorption or chemical bonding, enhancing its hydrophobic properties and thus giving the reinforcing layer preliminary waterproof characteristics.

[0014] Under high temperature and high pressure hot pressing conditions, the adhesive undergoes further cross-linking reaction, significantly improving the bonding force between fibers. The hydrophobic modifier cures at high temperature, enhancing its adhesion to the fiber surface and improving the overall hydrophobic properties of the reinforcing layer. After hot pressing, the reinforcing layer forms a high-strength, dense fiber network structure. This structure not only provides a robust base for the waterproof membrane but also effectively supports the waterproof functional layer and surface protective layer, playing a crucial role in resisting external mechanical stress and environmental erosion, thereby significantly extending the service life of the membrane.

[0015] Using bio-based polymers as the base material in the waterproofing functional layer is advantageous because bio-based polymers are derived from natural resources, are renewable and abundant, and their production process is more sustainable than that of petroleum-based polymers. Secondly, bio-based polymers typically possess good flexibility, helping the roll material adapt to the shape and condition of various substrate surfaces during installation. Simultaneously, the polar groups in bio-based polymers easily combine with the surface groups of inorganic fillers (such as silica nanoparticles and montmorillonite) to form a tight interfacial structure, significantly improving the dispersibility of the filler and the mechanical properties of the material. During thermosetting, bio-based polymers can form a dense network structure through cross-linking reactions between molecular chains, thereby enhancing the performance of the waterproofing functional layer.

[0016] Montmorillonite, bentonite, and regenerated cellulose are introduced as fillers in the waterproof functional layer. Montmorillonite is a layered silicate mineral formed by alternating layers of silicon-oxygen tetrahedra and aluminum-oxygen octahedra. It has a high specific surface area and nanoscale size. Its layered structure can extend the penetration path of water molecules or other substances, thereby improving the barrier performance of the waterproof functional layer. At the same time, montmorillonite has excellent heat resistance. Its structural stability allows it to maintain its physical and chemical properties at high temperatures, enhancing the high-temperature resistance of the waterproof functional layer. Bentonite also has a similar layered structure, but its interlayer distance is larger, its adsorption capacity is stronger, and it can expand to several times its original volume after absorbing water, further blocking the penetration of water molecules and other substances.

[0017] Modifying montmorillonite and bentonite using bio-based cationic surfactants allows the bio-based cationic surfactants to replace the cations between the montmorillonite and bentonite layers through ion exchange, thereby changing their interlayer structure properties. At the same time, the long-chain groups form hydrophobic barriers between the layers or on the surface, thus enhancing the waterproof performance.

[0018] Regenerated cellulose is a linear polymer material with high uniformity obtained from natural cellulose. It has high crystallinity and is rich in hydroxyl groups on its surface. Its hydroxyl groups stabilize the dispersion of fillers in the matrix by forming hydrogen bonds with the surfaces of montmorillonite and bentonite. In addition, the fibrous morphology of regenerated cellulose creates a physical intercalation with the polymer matrix, which helps to improve the density of the waterproof layer, reduce the formation of micropores and cracks, and thus improve the waterproof performance.

[0019] There is also a synergistic effect among the three: the layered structure of montmorillonite and bentonite significantly extends the water penetration path, while regenerated cellulose reduces water diffusion channels through its dense network structure; the synergistic effect of the three enhances waterproofing performance. Secondly, montmorillonite and bentonite provide nano-reinforcement, while regenerated cellulose forms a fiber network and interfacial bonding, comprehensively improving the tensile strength and toughness of the waterproofing layer. In addition, the thermal stability of montmorillonite and bentonite, combined with the semi-crystalline structure of regenerated cellulose, can improve the high-temperature resistance of the waterproofing layer. The synergistic effect of the three improves the aging resistance, environmental corrosion resistance, and overall service life of the waterproofing layer, providing high-performance assurance for waterproof membranes.

[0020] The present invention limits the modified filler to 20-30 parts by weight. When the amount of modified filler added is too much, it will lead to excessively high viscosity of the system, affecting the processing performance, and poor bonding between the filler and the polymer matrix, thereby reducing the overall strength and toughness, resulting in increased brittleness and easy cracking of the roll material. When the amount added is too little, it will lead to a decrease in the hydrophobicity and weather resistance of the functional layer, resulting in insufficient performance of the roll material.

[0021] This invention introduces silica nanoparticles into the waterproof functional layer. These nano- or micron-sized particles form a multi-level rough structure on the surface of the waterproof functional layer. This rough structure, combined with long-chain alkyl groups introduced through stearic acid modification, significantly reduces the free energy of the silica surface, thereby endowing the waterproof functional layer with superhydrophobic properties and further improving its waterproof performance. Within the polymer network, silica can also bridge microcracks and pores, inhibiting crack propagation and improving the waterproof layer's resistance to mechanical damage. Simultaneously, the high thermal stability and resistance to thermal decomposition of silica ensure that the waterproof functional layer maintains structural stability at high temperatures, reducing performance degradation caused by thermal decomposition. Furthermore, silica itself has a certain absorption and shielding effect on ultraviolet light, which can slow down the aging of the waterproof functional layer caused by ultraviolet radiation and extend its service life.

[0022] This invention specifies that the modified silica nanoparticles are 8-15 parts by weight. They are typically used as reinforcing agents and hydrophobic additives to improve the mechanical properties, hydrophobicity, and weather resistance of the functional layer. However, when too much modified silica nanoparticles are added, they are prone to uneven dispersion, increasing local stress concentration, which in turn leads to a decrease in the flexibility of the functional layer, causing the roll material to crack easily and affecting its service life. When the amount added is too small, the mechanical strength and hydrophobicity of the waterproof layer may decrease, leading to an increased risk of water penetration, while the weather resistance deteriorates, shortening the life of the roll material.

[0023] In the surface protective layer, perfluorooctyltriethoxysilane is a fluorinated silane coupling agent. Its triethoxysilane group is hydrolyzed to form silanol, which is then partially polycondensed to form oligomeric siloxane, forming a siloxane network on the matrix surface while retaining the fluorocarbon chain. This surface energy endows the material with excellent hydrophobic and protective properties. The polyurethane prepolymer is the basis of the film-forming material. By introducing a fluorinated silane solution, the silanol or oligomeric siloxane group may react chemically with the functional groups in the polyurethane to enhance the bonding strength, while retaining the fluorocarbon chain to provide hydrophobicity and antifouling properties, thus providing excellent performance for the surface protective layer.

[0024] Simultaneously, fluorinated polyurethane and silicone resin are introduced. Fluorinated polyurethane provides hydrophobicity through its low surface energy and enhances the flexibility of the protective layer through the flexible part of its molecular structure. Silicone resin, due to its unique Si–O bond structure, has excellent heat resistance and UV resistance, and can resist the oxidation and degradation caused by ultraviolet rays. The combination of the two forms a composite coating base with complementary properties.

[0025] Introducing reflective materials into the surface protective layer: Zirconia, with its high refractive index, can effectively reflect and refract visible and ultraviolet light, improving the coating's light reflectivity; titanium dioxide, with its extremely high refractive index and ability to shield against ultraviolet rays, can significantly reduce aging caused by ultraviolet rays; zinc oxide, by simultaneously absorbing and scattering ultraviolet rays, further enhances weather resistance. The introduction of these reflective materials works synergistically to effectively improve the weather resistance of the surface protective layer and extend the service life of the waterproof membrane.

[0026] Palmitic acid is used to modify reflective materials. Palmitic acid is a saturated fatty acid. The carboxyl groups in its molecules may interact with the surface of the reflective material through physical adsorption or chemical bonding to form a stable organic coating layer. After modification, the long-chain alkyl groups of palmitic acid form a low surface energy structure on the surface, which significantly enhances the hydrophobicity of the reflective material. At the same time, the photocatalytic activity generated by titanium dioxide under ultraviolet irradiation will accelerate the degradation of the surrounding matrix, while palmitic acid coating can effectively extend the coating life by isolating the active sites and inhibiting the photocatalytic reaction.

[0027] Secondly, the present invention provides a method for preparing an environmentally friendly biodegradable waterproof membrane, the method comprising:

[0028] S1: Bio-based fibers and natural fibers are sheared, washed, and dried to obtain pretreated fibers; binder is dispersed in deionized water to obtain binder solution; pretreated fibers are added to binder solution to obtain mixed solution A, and after stirring and reaction, hydrophobic modifier is added to obtain mixed solution B. The mixture is ultrasonically dispersed and stirred to obtain pulp, and the pulp is poured onto the forming wire of a wet papermaking equipment. A vacuum filtration device is used to form a wet fiber web, which is then placed in a hot press to obtain a preliminary reinforcing layer. After drying, the reinforcing layer is obtained.

[0029] S2: Montmorillonite and bentonite are dispersed in a bio-based cationic surfactant solution and stirred to react. After the reaction is completed, the mixture is filtered, washed and dried to obtain a modified mixed filler. The modified mixed filler is added to a regenerated cellulose solution, and then polyvinylpyrrolidone is added. The mixture is ultrasonically dispersed to obtain a filler mixed solution. After freeze-drying, the modified filler is obtained.

[0030] Silica nanoparticles were dispersed in ethanol and stirred to obtain a silica nanoparticle dispersion. Stearic acid was added to the dispersion, and after constant temperature reaction, the mixture was filtered, washed, and dried to obtain modified silica nanoparticles.

[0031] Bio-based polymers and modified silica nanoparticles were mixed under stirring, followed by the addition of modified fillers, toughening agents, and antioxidants. The mixture was stirred to obtain a waterproof functional layer substrate, which was then fed into a twin-screw extruder for melt blending. The resulting melt blend was then stretched into a film and subjected to thermosetting treatment to obtain the waterproof functional layer.

[0032] S3: Disperse perfluorooctyltriethoxysilane in anhydrous ethanol, add deionized water, adjust the pH by adding acetic acid dropwise, and stir to obtain a fluorinated silane solution; disperse polyurethane prepolymer in anhydrous toluene, add the fluorinated silane solution dropwise, add triethylamine, react at a constant temperature to obtain reaction solution C, and rotary evaporate to obtain modified polyurethane;

[0033] Palmitic acid was dissolved in anhydrous ethanol to obtain a palmitic acid solution. The reflective material was added to the palmitic acid solution, stirred and reacted, and then filtered, washed and dried to obtain a fatty acid-coated reflective material.

[0034] Fluorinated polyurethane and silicone resin are mixed and stirred. Then fatty acid-coated reflective material, ultraviolet absorber and hydrophobic modifier are added in sequence and stirred to obtain a surface protective coating.

[0035] S4: After cleaning the contact surfaces of the reinforcing layer and the waterproof functional layer, they are stacked and placed in a hot press for lamination. After completion, the composite material is obtained by keeping it in a pressed state and allowing it to cool naturally to room temperature. The surface protective coating is then applied to the surface of the waterproof functional layer and baked to cure, resulting in an environmentally friendly biodegradable waterproof membrane.

[0036] As a preferred embodiment of the present invention, in step S1, the concentration of the adhesive is 0.1-0.2 g / mL, for example, it can be 0.1 g / mL, 0.11 g / mL, 0.12 g / mL, 0.13 g / mL, 0.14 g / mL, 0.15 g / mL, 0.16 g / mL, 0.17 g / mL, 0.18 g / mL, 0.19 g / mL or 0.2 g / mL, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0037] As a preferred technical solution of the present invention, in step S2, the mass ratio of montmorillonite to bentonite is (1-2):1, for example, it can be 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1 or 2.0:1, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] In some alternative examples, the bio-based cationic surfactant solution has a mass fraction of 2-5 wt.%, for example, it may be 2.0 wt.%, 2.2 wt.%, 2.4 wt.%, 2.6 wt.%, 2.8 wt.%, 3.0 wt.%, 3.2 wt.%, 3.4 wt.%, 3.6 wt.%, 3.8 wt.%, 4.0 wt.%, 4.2 wt.%, 4.4 wt.%, 4.6 wt.%, 4.8 wt.%, or 5.0 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0039] In some optional instances, the total mass ratio of the bio-based cationic surfactant to montmorillonite and bentonite is 1:(15-25), for example, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24 or 1:25, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0040] In some alternative examples, the mass ratio of the modified mixed filler to regenerated cellulose is (5-10):1, for example, it can be 5.0:1, 5.5:1, 6.0:1, 6.5:1, 7.0:1, 7.5:1, 8.0:1, 8.5:1, 9.0:1, 9.5:1 or 10.0:1, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0041] In some alternative examples, the regenerated cellulose solution has a mass fraction of 5-10 wt.%, for example, 5.0 wt.%, 5.5 wt.%, 6.0 wt.%, 6.5 wt.%, 7.0 wt.%, 7.5 wt.%, 8.0 wt.%, 8.5 wt.%, 9.0 wt.%, 9.5 wt.%, or 10.0 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0042] In some alternative examples, the amount of polyvinylpyrrolidone fed is 2-5 wt.% of the regenerated cellulose, for example, it can be 2.0 wt.%, 2.2 wt.%, 2.4 wt.%, 2.6 wt.%, 2.8 wt.%, 3.0 wt.%, 3.2 wt.%, 3.4 wt.%, 3.6 wt.%, 3.8 wt.%, 4.0 wt.%, 4.2 wt.%, 4.4 wt.%, 4.6 wt.%, 4.8 wt.%, or 5.0 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0043] In some optional instances, the mass ratio of the silica nanoparticles to stearic acid is (10-20):1, for example, it can be 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1 or 20:1, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0044] In some alternative instances, the stearic acid ethanol solution has a mass fraction of 1-5 wt.%, for example, it may be 1.0 wt.%, 1.5 wt.%, 2.0 wt.%, 2.5 wt.%, 3.0 wt.%, 3.5 wt.%, 4.0 wt.%, 4.5 wt.%, or 5.0 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0045] As a preferred technical solution of the present invention, in step S3, the mass ratio of perfluorooctyltriethoxysilane to polyurethane prepolymer is 1:(5-10), for example, it can be 1:5.0, 1:5.5, 1:6.0, 1:6.5, 1:7.0, 1:7.5, 1:8.0, 1:8.5, 1:9.0, 1:9.5 or 1:10.0, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] In some alternative instances, the concentration of the palmitic acid solution is 0.1-0.5 mol / L, for example, 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L, 0.3 mol / L, 0.35 mol / L, 0.4 mol / L, 0.45 mol / L or 0.5 mol / L, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0047] In some alternative instances, the mass ratio of the reflective material to the palmitic acid solution is 1:(10-20), for example, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0048] As a preferred technical solution of the present invention, in step S4, the temperature at which the reinforcing layer and the waterproof functional layer are bonded in the hot press is 150-180℃, for example, it can be 150℃, 152℃, 154℃, 156℃, 158℃, 160℃, 162℃, 164℃, 166℃, 168℃, 170℃, 172℃, 174℃, 176℃, 178℃ or 180℃, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0049] In some alternative instances, the pressure at which the reinforcing layer and the waterproof functional layer are bonded in a hot press is 5-10 MPa, for example, 5.0 MPa, 5.5 MPa, 6.0 MPa, 6.5 MPa, 7.0 MPa, 7.5 MPa, 8.0 MPa, 8.5 MPa, 9.0 MPa, 9.5 MPa or 10.0 MPa, but not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0050] In some optional instances, the bonding time between the reinforcing layer and the waterproof functional layer in the hot press is 10-20 minutes, for example, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes or 20 minutes, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0051] In some optional instances, the baking and curing temperature is 80-100°C, for example, 80°C, 82°C, 84°C, 86°C, 88°C, 90°C, 92°C, 94°C, 96°C, 98°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0052] In some optional instances, the baking and curing time is 20-30 min, for example, it can be 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min or 30 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0053] As a preferred embodiment of the present invention, the reinforcing layer comprises the following components in parts by weight:

[0054]

[0055] In some optional instances, the bio-based fiber is in the range of 40-50 parts by weight, for example, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 parts by weight, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0056] In some alternative instances, the natural fiber mass fraction is 30-40 parts, such as 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40 parts, but is not limited to the listed values; other unlisted values ​​within this range also apply.

[0057] In some optional instances, the adhesive is in parts by weight of 15-25, for example, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0058] In some optional instances, the hydrophobic modifier is in the range of 5-10 parts by weight, for example, 5.0 parts, 5.5 parts, 6.0 parts, 6.5 parts, 7.0 parts, 7.5 parts, 8.0 parts, 8.5 parts, 9.0 parts, 9.5 parts, or 10.0 parts, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0059] As a preferred embodiment of the present invention, the waterproof functional layer comprises the following components in parts by weight:

[0060]

[0061]

[0062] In some optional instances, the bio-based polymer is in the range of 60-80 parts by weight, for example, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78 or 80 parts, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0063] In some alternative examples, the modified silica nanoparticles are in the range of 8-15 parts by weight, for example, 8.0 parts, 8.5 parts, 9.0 parts, 9.5 parts, 10.0 parts, 10.5 parts, 11.0 parts, 11.5 parts, 12.0 parts, 12.5 parts, 13.0 parts, 13.5 parts, 14.0 parts, 14.5 parts, or 15.0 parts, but are not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0064] In some optional instances, the modified filler is in the range of 20-30 parts by weight, for example, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 parts, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0065] In some optional instances, the toughening agent is in the range of 1 to 5 parts by weight, for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 or 5.0 parts, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0066] In some optional instances, the antioxidant is present in parts by weight of 1 to 3 parts, such as 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8 or 3.0 parts, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0067] As a preferred embodiment of the present invention, the surface protective layer comprises the following components in parts by weight:

[0068]

[0069] In some alternative examples, the fluorinated polyurethane is in the range of 40-60 parts by weight, for example, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58 or 60 parts, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0070] In some alternative examples, the silicone resin is in parts by weight of 10-30 parts, for example, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30 parts, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0071] In some optional examples, the fatty acid-coated reflective material is in the range of 5-20 parts by weight, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 parts, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0072] In some alternative examples, the antioxidant is in parts by weight of 0.5 to 2 parts, for example, 0.5, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8 or 2.0 parts, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0073] In some alternative examples, the amount of ultraviolet absorber is 0.5-2 parts by weight, for example, 0.5 parts, 0.6 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts or 2.0 parts, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0074] In some optional instances, the hydrophobic modifier is present in parts by weight of 0.5 to 2 parts, for example, 0.5, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8 or 2.0 parts, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0075] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0076] (1) The reinforcing layer uses bio-based fibers with high toughness and biodegradability and natural fibers with good strength and tolerance as the main materials, which provides a reliable mechanical property basis for the reinforcing layer and endows the roll material with environmental protection and biodegradability.

[0077] (2) The waterproof functional layer uses renewable and flexible bio-based polymers as the base material, which makes the production process more sustainable and helps the roll material adapt to various substrate surface conditions during the laying process; secondly, the polar groups in the bio-based polymers are easy to combine with inorganic fillers to form a tight interface structure, which improves the mechanical properties of the material; and during the thermosetting process, the bio-based polymers can also form a dense network structure through the cross-linking reaction between molecular chains, which enhances the performance of the waterproof functional layer.

[0078] (3) Montmorillonite, bentonite, and regenerated cellulose are introduced as fillers in the waterproof functional layer: The layered structure of montmorillonite and bentonite significantly extends the water penetration path, while the dense network structure of regenerated cellulose reduces the water diffusion channels. The three work synergistically to improve waterproof performance. In addition, the thermal stability of montmorillonite and bentonite, combined with the semi-crystalline structure of regenerated cellulose, can improve the high-temperature resistance of the waterproof layer. The synergistic effect of the three improves the aging resistance, environmental erosion resistance, and overall service life of the waterproof functional layer, providing high-performance assurance for waterproof membranes.

[0079] (4) Perfluorooctyltriethoxysilane modified polyurethane is used in the surface protective layer. By introducing fluorinated silane solution, silanol or oligomeric siloxane groups may react chemically with the functional groups in polyurethane to enhance the bonding strength. At the same time, the fluorocarbon chain is retained to provide hydrophobicity and antifouling properties, thus providing excellent performance for the surface protective layer.

[0080] (5) Fluorinated polyurethane and silicone resin are introduced at the same time. Fluorinated polyurethane provides hydrophobicity through its low surface energy and enhances the flexibility of the protective layer through the flexible part of the molecular structure. Silicone resin has excellent heat resistance and UV resistance due to its unique Si–O bond structure. It can resist the oxidation and degradation caused by ultraviolet rays. The combination of the two forms a composite coating base with complementary properties. Attached Figure Description

[0081] Figure 1 A flowchart illustrating the preparation method of the environmentally friendly biodegradable waterproof membrane provided in Embodiment 1 of the present invention;

[0082] Figure 2 This is a structural schematic diagram of the environmentally friendly biodegradable waterproof membrane provided by the present invention.

[0083] Reference numerals: 1. Substrate; 2. Reinforcing layer; 3. Waterproof functional layer; 4. Surface protective layer. Detailed Implementation

[0084] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0085] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products.

[0086] Example 1

[0087] like Figure 1 As shown, this embodiment provides an environmentally friendly biodegradable waterproof membrane and its preparation method, the preparation method specifically including the following steps:

[0088] S1: Bio-based fibers and natural fibers are pretreated and dispersed in a binder solution to obtain mixed solution A. A hydrophobic modifier is added to obtain mixed solution B. The mixture is ultrasonically dispersed and stirred to obtain a slurry. The reinforcing layer is obtained through a wet molding process.

[0089] Specifically, S1: 45 parts of polylactic acid fiber and 30 parts of flax fiber are cut, washed, and dried to obtain pretreated fiber; 20 parts of polyvinyl alcohol are dispersed in deionized water to obtain a polyvinyl alcohol solution with a concentration of 0.1 g / mL; the pretreated fiber is added to the polyvinyl alcohol solution to obtain mixed solution A, and after stirring and reacting at a stirring speed of 800 rpm for 20 min, 8 parts of stearic acid are added to obtain mixed solution B. The mixture is ultrasonically dispersed and stirred to obtain pulp, wherein the ultrasonic dispersion power is 250 W, the time is 10 min, the stirring temperature is 45℃, and the time is 15 min. The pulp is poured onto the forming wire of a wet papermaking equipment, and a wet fiber web is formed using a vacuum filtration device. The web is then placed in a hot press to obtain a preliminary reinforcing layer, wherein the hot pressing temperature is 165℃, the pressure is 8 MPa, and the time is 12 min. After drying, reinforcing layer 2 is obtained.

[0090] S2: Montmorillonite and bentonite were dispersed in a bio-based cationic surfactant solution to obtain a modified mixed filler. This was then added to a regenerated cellulose solution, and polyvinylpyrrolidone was added to treat it to obtain a modified filler. Silica nanoparticles were dispersed in a stearic acid ethanol solution to obtain modified silica nanoparticles.

[0091] A waterproof functional layer is obtained by mixing bio-based polymers, modified silica nanoparticles, modified fillers, toughening agents, and antioxidants, melt blending, casting, and then thermosetting.

[0092] Specifically, S2: Montmorillonite and bentonite are dispersed in a 2 wt.% betaine solution at a mass ratio of 1:1, wherein the total mass ratio of betaine to montmorillonite and bentonite is 1:20. The mixture is stirred at 55°C for 25 min. After the reaction, it is filtered, washed, and dried to obtain a modified mixed filler. The modified mixed filler is added to a 7.5 wt.% regenerated cellulose solution, wherein the mass ratio of the modified mixed filler to regenerated cellulose is 5:1. Polyvinylpyrrolidone, accounting for 3.4 wt.% of the regenerated cellulose, is then added. The mixture is ultrasonically dispersed to obtain a filler mixed solution. After freeze-drying, the modified filler is obtained.

[0093] Silica nanoparticles were dispersed in ethanol and stirred to obtain a silica nanoparticle dispersion. Stearic acid was added to the dispersion, wherein the mass fraction of stearic acid in ethanol was 1 wt.% and the mass ratio of silica nanoparticles to stearic acid was 10:1. The mixture was reacted at a constant temperature of 75℃ for 3 hours, and then filtered, washed and dried to obtain modified silica nanoparticles.

[0094] 70 parts of polylactic acid, polybutylene succinate and 10 parts of modified silica nanoparticles were mixed under stirring. Then, 25 parts of modified filler, 3 parts of glycerol and 2.5 parts of vitamin E were added and stirred to obtain a waterproof functional layer substrate. The substrate was then fed into a twin-screw extruder for melt blending. The melt blending temperature was 182℃, the time was 15min and the screw speed was 180rpm. The resulting melt blend was stretched into a film and then subjected to thermosetting treatment to obtain waterproof functional layer 3.

[0095] S3: Modified polyurethane is obtained by modifying polyurethane prepolymer with perfluorooctyltriethoxysilane; fatty acid-coated reflective material is obtained by modifying reflective material with palmitic acid; after mixing fluorinated polyurethane and silicone resin, fatty acid-coated reflective material, ultraviolet absorber and hydrophobic modifier are added in sequence and mixed evenly to obtain surface protective coating.

[0096] Specifically, S3: Perfluorooctyltriethoxysilane is dispersed in anhydrous ethanol at a mass fraction of 8 wt.%, deionized water is added, wherein the mass ratio of anhydrous ethanol to deionized water is 90:10, acetic acid is added dropwise to adjust the pH to 4, and the mixture is stirred to obtain a fluorinated silane solution; polyurethane prepolymer is dispersed in anhydrous toluene, wherein the mass fraction of polyurethane prepolymer in anhydrous ethanol is 12.5 wt.%, a fluorinated silane solution is added dropwise, wherein the mass ratio of perfluorooctyltriethoxysilane to polyurethane prepolymer is 1:8, triethylamine is added in a molar ratio of 1:1 to perfluorooctyltriethoxysilane, and the mixture is reacted at a constant temperature of 65°C for 1.5 h to obtain reaction solution C, which is then rotary evaporated to obtain modified polyurethane;

[0097] Palmitic acid was dissolved in anhydrous ethanol to obtain a palmitic acid solution with a concentration of 0.25 mol / L. Zirconia was added to the palmitic acid solution, wherein the mass ratio of zirconium oxide to palmitic acid solution was 1:20. The reaction was stirred at 54℃ for 3.4 h. After filtration, washing and drying, fatty acid-coated reflective material was obtained.

[0098] Mix 50 parts of fluorinated polyurethane and 22 parts of silicone resin, stir and mix, then add 10 parts of fatty acid-coated reflective material, 1 part of vitamin E, 1.5 parts of ultraviolet absorber UV-326 and 2.2 parts of stearic acid in sequence and stir to obtain surface protective coating 4.

[0099] S4: After cleaning the contact surfaces of the reinforcing layer 2 and the waterproof functional layer 3, they are stacked and laminated in a hot press. The hot press lamination temperature is 165℃, the pressure is 7MPa, and the time is 15min. After completion, the laminated material is allowed to cool naturally to room temperature while still pressed to obtain the composite material. The surface protective coating 4 is then applied to the surface of the waterproof functional layer 3, and baked at 90℃ for 25min to obtain an environmentally friendly biodegradable waterproof membrane. Figure 2 As shown.

[0100] Example 2

[0101] This embodiment provides an environmentally friendly biodegradable waterproof membrane and its preparation method, the preparation method specifically including the following steps:

[0102] S1: Bio-based fibers and natural fibers are pretreated and dispersed in a binder solution to obtain mixed solution A. A hydrophobic modifier is added to obtain mixed solution B. The mixture is ultrasonically dispersed and stirred to obtain a slurry. The reinforcing layer is obtained through a wet molding process.

[0103] Specifically, S1: 40 parts of polyhydroxy fatty acid fiber and 40 parts of bamboo fiber are cut, washed, and dried to obtain pretreated fiber; 25 parts of starch glue are dispersed in deionized water to obtain a starch glue solution with a concentration of 0.15 g / mL; the pretreated fiber is added to the starch glue solution to obtain mixed solution A, and after stirring and reacting at a stirring speed of 900 rpm for 15 min, 5 parts of sodium stearate are added to obtain mixed solution B. The mixture is ultrasonically dispersed and stirred to obtain pulp, wherein the ultrasonic dispersion power is 200 W, the time is 15 min, the stirring temperature is 40℃, and the time is 10 min. The pulp is poured onto the forming wire of a wet papermaking equipment, and a wet fiber web is formed using a vacuum filtration device. The web is then placed in a hot press to obtain a preliminary reinforcing layer, wherein the hot pressing temperature is 180℃, the pressure is 5 MPa, and the time is 15 min. After drying, reinforcing layer 2 is obtained.

[0104] S2: Montmorillonite and bentonite were dispersed in a bio-based cationic surfactant solution to obtain a modified mixed filler. This was then added to a regenerated cellulose solution, and polyvinylpyrrolidone was added to treat it to obtain a modified filler. Silica nanoparticles were dispersed in a stearic acid ethanol solution to obtain modified silica nanoparticles.

[0105] A waterproof functional layer is obtained by mixing bio-based polymers, modified silica nanoparticles, modified fillers, toughening agents, and antioxidants, melt blending, casting, and then thermosetting.

[0106] Specifically, S2: Montmorillonite and bentonite are dispersed in a 5 wt.% lauramidopropyl betaine solution at a mass ratio of 1.5:1, wherein the total mass ratio of lauramidopropyl betaine to montmorillonite and bentonite is 1:15. The mixture is stirred at 50°C for 30 min. After the reaction, it is filtered, washed, and dried to obtain a modified mixed filler. The modified mixed filler is added to a 5 wt.% regenerated cellulose solution, wherein the mass ratio of the modified mixed filler to regenerated cellulose is 8:1. Then, 2 wt.% polyvinylpyrrolidone is added, and the mixture is ultrasonically dispersed to obtain a filler mixed solution. After freeze-drying, the modified filler is obtained.

[0107] Silica nanoparticles were dispersed in ethanol and stirred to obtain a silica nanoparticle dispersion. Stearic acid was added to the dispersion, wherein the mass fraction of stearic acid in ethanol was 3 wt.% and the mass ratio of silica nanoparticles to stearic acid was 18:1. The mixture was reacted at a constant temperature of 78℃ for 4 h, and then filtered, washed and dried to obtain modified silica nanoparticles.

[0108] 80 parts of polybutylene succinate and 8 parts of modified silica nanoparticles were mixed under stirring. Then, 20 parts of modified filler, 1 part of polyethylene glycol, and 1 part of antioxidant 1010 were added and stirred to obtain a waterproof functional layer substrate. The substrate was then fed into a twin-screw extruder for melt blending at a temperature of 190°C for 20 minutes and a screw speed of 100 rpm. The resulting melt blend was stretched into a film and then subjected to thermosetting treatment to obtain waterproof functional layer 3.

[0109] S3: Modified polyurethane is obtained by modifying polyurethane prepolymer with perfluorooctyltriethoxysilane; fatty acid-coated reflective material is obtained by modifying reflective material with palmitic acid; after mixing fluorinated polyurethane and silicone resin, fatty acid-coated reflective material, ultraviolet absorber and hydrophobic modifier are added in sequence and mixed evenly to obtain surface protective coating.

[0110] Specifically, S3: Perfluorooctyltriethoxysilane is dispersed in anhydrous ethanol at a mass fraction of 5 wt.%, deionized water is added, wherein the mass ratio of anhydrous ethanol to deionized water is 95:5, acetic acid is added dropwise to adjust the pH to 4.5, and the mixture is stirred to obtain a fluorinated silane solution; polyurethane prepolymer is dispersed in anhydrous toluene, wherein the mass fraction of polyurethane prepolymer in anhydrous ethanol is 15 wt.%, a fluorinated silane solution is added dropwise, wherein the mass ratio of perfluorooctyltriethoxysilane to polyurethane prepolymer is 1:10, triethylamine is added at a molar ratio of 1.5:1 to perfluorooctyltriethoxysilane, and the mixture is reacted at a constant temperature of 60°C for 2 h to obtain reaction solution C, which is then rotary evaporated to obtain modified polyurethane;

[0111] Palmitic acid was dissolved in anhydrous ethanol to obtain a palmitic acid solution with a concentration of 0.1 mol / L. Titanium dioxide was added to the palmitic acid solution, wherein the mass ratio of titanium dioxide to palmitic acid solution was 1:15. The mixture was stirred at 58°C for 2 hours. After filtration, washing and drying, fatty acid-coated reflective material was obtained.

[0112] Mix 60 parts of fluorinated polyurethane and 30 parts of silicone resin, stir and mix, then add 15 parts of fatty acid coated reflective material, 0.5 parts of antioxidant 1010, 0.5 parts of ultraviolet absorber UV-328 and 3 parts of sodium stearate in sequence and stir and mix to obtain surface protective coating 4.

[0113] S4: After cleaning the contact surfaces of the reinforcing layer 2 and the waterproof functional layer 3, they are stacked and placed in a hot press for lamination. The hot press lamination temperature is 150℃, the pressure is 5MPa, and the time is 20min. After completion, the composite material is obtained by naturally cooling to room temperature while maintaining the pressed state. The surface protective coating 4 is applied to the surface of the waterproof functional layer 3 and baked at 100℃ for 30min to obtain an environmentally friendly biodegradable waterproof membrane.

[0114] Example 3

[0115] This embodiment provides an environmentally friendly biodegradable waterproof membrane and its preparation method, the preparation method specifically including the following steps:

[0116] S1: Bio-based fibers and natural fibers are pretreated and dispersed in a binder solution to obtain mixed solution A. A hydrophobic modifier is added to obtain mixed solution B. The mixture is ultrasonically dispersed and stirred to obtain a slurry. The reinforcing layer is obtained through a wet molding process.

[0117] Specifically, S1: 50 parts of polylactic acid fiber and 35 parts of flax fiber are cut, washed, and dried to obtain pretreated fiber; 15 parts of polyvinyl alcohol are dispersed in deionized water to obtain a polyvinyl alcohol solution with a concentration of 0.18 g / mL; the pretreated fiber is added to a polyvinyl alcohol and starch glue solution to obtain mixed solution A. After stirring and reacting at a stirring speed of 1000 rpm for 30 min, 10 parts of zinc stearate are added to obtain mixed solution B. The mixture is ultrasonically dispersed and stirred to obtain pulp, wherein the ultrasonic dispersion power is 270 W, the time is 20 min, the stirring temperature is 50℃, and the time is 18 min. The pulp is poured onto the forming wire of a wet papermaking equipment, and a wet fiber web is formed using a vacuum filtration device. The web is then placed in a hot press to obtain a preliminary reinforcing layer, wherein the hot pressing temperature is 150℃, the pressure is 7.5 MPa, and the time is 10 min. After drying, reinforcing layer 2 is obtained.

[0118] S2: Montmorillonite and bentonite were dispersed in a bio-based cationic surfactant solution to obtain a modified mixed filler. This was then added to a regenerated cellulose solution, and polyvinylpyrrolidone was added to treat it to obtain a modified filler. Silica nanoparticles were dispersed in a stearic acid ethanol solution to obtain modified silica nanoparticles.

[0119] A waterproof functional layer is obtained by mixing bio-based polymers, modified silica nanoparticles, modified fillers, toughening agents, and antioxidants, melt blending, casting, and then thermosetting.

[0120] Specifically, S2: Montmorillonite and bentonite are dispersed in a 3.5 wt.% betaine solution at a mass ratio of 1.8:1, where the total mass ratio of betaine to montmorillonite and bentonite is 1:25. The mixture is stirred at 57°C for 20 min. After the reaction, it is filtered, washed, and dried to obtain a modified mixed filler. The modified mixed filler is added to a regenerated cellulose solution at a mass ratio of 8.8 wt.%, where the mass ratio of the modified mixed filler to regenerated cellulose is 10:1. Polyvinylpyrrolidone (PVP) accounting for 4.6 wt.% of the regenerated cellulose is then added. The mixture is ultrasonically dispersed to obtain a filler mixed solution. After freeze-drying, the modified filler is obtained.

[0121] Silica nanoparticles were dispersed in ethanol and stirred to obtain a silica nanoparticle dispersion. Stearic acid was added to the dispersion, wherein the mass fraction of stearic acid in ethanol was 4.4 wt.% and the mass ratio of silica nanoparticles to stearic acid was 15:1. The mixture was reacted at a constant temperature of 80℃ for 3.5 h, and then filtered, washed and dried to obtain modified silica nanoparticles.

[0122] 60 parts of polylactic acid and 12 parts of modified silica nanoparticles were mixed under stirring, followed by the addition of 30 parts of modified filler, 5 parts of glycerol and 3 parts of antioxidant 1076. The mixture was stirred to obtain a waterproof functional layer substrate, which was then fed into a twin-screw extruder for melt blending at a temperature of 170°C for 12 minutes and a screw speed of 150 rpm. The resulting melt blend was then stretched into a film and subjected to thermosetting treatment to obtain waterproof functional layer 3.

[0123] S3: Modified polyurethane is obtained by modifying polyurethane prepolymer with perfluorooctyltriethoxysilane; fatty acid-coated reflective material is obtained by modifying reflective material with palmitic acid; after mixing fluorinated polyurethane and silicone resin, fatty acid-coated reflective material, ultraviolet absorber and hydrophobic modifier are added in sequence and mixed evenly to obtain surface protective coating.

[0124] Specifically, S3: Perfluorooctyltriethoxysilane is dispersed in anhydrous ethanol at a mass fraction of 7.5 wt.%, deionized water is added, wherein the mass ratio of anhydrous ethanol to deionized water is 92:8, acetic acid is added dropwise to adjust the pH to 5, and the mixture is stirred to obtain a fluorinated silane solution; polyurethane prepolymer is dispersed in anhydrous toluene, wherein the mass fraction of polyurethane prepolymer in anhydrous ethanol is 13.8 wt.%, a fluorinated silane solution is added dropwise, wherein the mass ratio of perfluorooctyltriethoxysilane to polyurethane prepolymer is 1:5, triethylamine is added at a molar ratio of 1.25:1 to perfluorooctyltriethoxysilane, and the mixture is reacted at a constant temperature of 70°C for 1 h to obtain reaction solution C, which is then rotary evaporated to obtain modified polyurethane;

[0125] Palmitic acid was dissolved in anhydrous ethanol to obtain a palmitic acid solution with a concentration of 0.34 mol / L. Zinc oxide was added to the palmitic acid solution, wherein the mass ratio of zinc oxide to palmitic acid solution was 1:10. The reaction was stirred at 50°C for 2.8 h. After filtration, washing and drying, fatty acid-coated reflective material was obtained.

[0126] Mix 40 parts of fluorinated polyurethane and 10 parts of silicone resin, stir and mix, then add 5 parts of fatty acid-coated reflective material, 2 parts of antioxidant 1076, 2 parts of ultraviolet absorber UV-327 and 0.5 parts of zinc stearate in sequence and stir to obtain surface protective coating 4.

[0127] S4: After cleaning the contact surfaces of the reinforcing layer 2 and the waterproof functional layer 3, they are stacked and placed in a hot press for lamination. The hot press lamination temperature is 180℃, the pressure is 8.8MPa, and the time is 18min. After completion, the composite material is obtained by naturally cooling to room temperature while maintaining the pressed state. The surface protective coating 4 is applied to the surface of the waterproof functional layer 3 and baked at 80℃ for 20min to obtain an environmentally friendly biodegradable waterproof membrane.

[0128] Example 4

[0129] This embodiment provides an environmentally friendly biodegradable waterproof membrane and its preparation method, the preparation method specifically including the following steps:

[0130] S1: Bio-based fibers and natural fibers are pretreated and dispersed in a binder solution to obtain mixed solution A. A hydrophobic modifier is added to obtain mixed solution B. The mixture is ultrasonically dispersed and stirred to obtain a slurry. The reinforcing layer is obtained through a wet molding process.

[0131] Specifically, S1: 48 parts of polyhydroxy fatty acid fiber and 37 parts of bamboo fiber were sheared, washed, and dried to obtain pretreated fiber; 22 parts of starch glue were dispersed in deionized water to obtain a starch glue solution with a concentration of 0.2 g / mL; the pretreated fiber was added to the starch glue solution to obtain mixed solution A, and after stirring and reacting at a stirring speed of 920 rpm for 24 min, 8.6 parts of sodium stearate and zinc stearate were added to obtain mixed solution B, which was ultrasonically dispersed and stirred to obtain pulp, wherein the ultrasonic dispersion power was 300 W, the time was 18 min, the stirring temperature was 47℃, and the time was 20 min; the pulp was poured onto the forming wire of a wet papermaking equipment, and a wet fiber web was formed using a vacuum filtration device; it was placed in a hot press to obtain a preliminary reinforcing layer, wherein the hot pressing temperature was 172℃, the pressure was 10 MPa, and the time was 14 min; after drying, reinforcing layer 2 was obtained.

[0132] S2: Montmorillonite and bentonite were dispersed in a bio-based cationic surfactant solution to obtain a modified mixed filler. This was then added to a regenerated cellulose solution, and polyvinylpyrrolidone was added to treat it to obtain a modified filler. Silica nanoparticles were dispersed in a stearic acid ethanol solution to obtain modified silica nanoparticles.

[0133] A waterproof functional layer is obtained by mixing bio-based polymers, modified silica nanoparticles, modified fillers, toughening agents, and antioxidants, melt blending, casting, and then thermosetting.

[0134] Specifically, S2: Montmorillonite and bentonite are dispersed in a 4.2 wt.% lauramidopropyl betaine solution at a mass ratio of 2:1, wherein the total mass ratio of lauramidopropyl betaine to montmorillonite and bentonite is 1:22. The mixture is stirred at 60℃ for 28 min. After the reaction, it is filtered, washed, and dried to obtain a modified mixed filler. The modified mixed filler is added to a 10 wt.% regenerated cellulose solution, wherein the mass ratio of the modified mixed filler to regenerated cellulose is 7.5:1. Then, 5 wt.% polyvinylpyrrolidone is added, and the mixture is ultrasonically dispersed to obtain a filler mixed solution. After freeze-drying, the modified filler is obtained.

[0135] Silica nanoparticles were dispersed in ethanol and stirred to obtain a silica nanoparticle dispersion. Stearic acid was added to the dispersion, wherein the mass fraction of stearic acid in ethanol was 5 wt.% and the mass ratio of silica nanoparticles to stearic acid was 20:1. The mixture was reacted at a constant temperature of 72℃ for 3.8 h, and then filtered, washed and dried to obtain modified silica nanoparticles.

[0136] 74 parts of polybutylene succinate and 15 parts of modified silica nanoparticles were mixed under stirring. Then, 28 parts of modified filler, 4.2 parts of polyethylene glycol, 2 parts of antioxidant 1010 and antioxidant 1076 were added and stirred to obtain a waterproof functional layer substrate. The substrate was then added to a twin-screw extruder for melt blending. The melt blending temperature was 187℃, the time was 10 min, and the screw speed was 200 rpm. The resulting melt blend was stretched into a film and then subjected to thermosetting treatment to obtain waterproof functional layer 3.

[0137] S3: Modified polyurethane is obtained by modifying polyurethane prepolymer with perfluorooctyltriethoxysilane; fatty acid-coated reflective material is obtained by modifying reflective material with palmitic acid; after mixing fluorinated polyurethane and silicone resin, fatty acid-coated reflective material, ultraviolet absorber and hydrophobic modifier are added in sequence and mixed evenly to obtain surface protective coating.

[0138] Specifically, S3: Perfluorooctyltriethoxysilane is dispersed in anhydrous ethanol at a mass fraction of 10 wt.%, deionized water is added, wherein the mass ratio of anhydrous ethanol to deionized water is 93:7, acetic acid is added dropwise to adjust the pH to 4.8, and the mixture is stirred to obtain a fluorinated silane solution; polyurethane prepolymer is dispersed in anhydrous toluene, wherein the mass fraction of the polyurethane prepolymer in anhydrous ethanol is 10 wt.%, a fluorinated silane solution is added dropwise, wherein the mass ratio of perfluorooctyltriethoxysilane to polyurethane prepolymer is 1:7.4, triethylamine is added at a molar ratio of 1.35:1 to perfluorooctyltriethoxysilane, and the mixture is reacted at a constant temperature of 67°C for 1.2 h to obtain reaction solution C, which is then rotary evaporated to obtain modified polyurethane;

[0139] Palmitic acid was dissolved in anhydrous ethanol to obtain a palmitic acid solution with a concentration of 0.5 mol / L. Titanium dioxide and zinc oxide were added to the palmitic acid solution, wherein the mass ratio of titanium dioxide and zinc oxide to palmitic acid solution was 1:17. The reaction was stirred at 60℃ for 4 h. After filtration, washing and drying, fatty acid coated reflective material was obtained.

[0140] Mix 55 parts of fluorinated polyurethane and 32 parts of silicone resin, stir and mix, then add 20 parts of fatty acid coated reflective material, 1.2 parts of antioxidant 1010, antioxidant 1076, 1.8 parts of ultraviolet absorber UV-531, 1.8 parts of sodium stearate and zinc stearate in sequence and stir to obtain surface protective coating 4.

[0141] S4: After cleaning the contact surfaces of the reinforcing layer 2 and the waterproof functional layer 3, they are stacked and placed in a hot press for lamination. The hot press lamination temperature is 175℃, the pressure is 10MPa, and the time is 10min. After completion, the composite material is obtained by naturally cooling to room temperature while maintaining the pressed state. The surface protective coating 4 is applied to the surface of the waterproof functional layer 3 and baked at 95℃ for 28min to obtain an environmentally friendly biodegradable waterproof membrane.

[0142] Comparative Example 1

[0143] This comparative example provides an environmentally friendly biodegradable waterproof membrane. The difference from Example 1 is that in step S2, the modified silica nanoparticles are 20 parts by weight. Other operating steps and process parameters are exactly the same as in Example 1.

[0144] Comparative Example 2

[0145] This comparative example provides an environmentally friendly biodegradable waterproof membrane. The difference from Example 1 is that in step S2, the modified silica nanoparticles are 2 parts by weight, while the other operating steps and process parameters are exactly the same as in Example 1.

[0146] Comparative Example 3

[0147] This comparative example provides an environmentally friendly biodegradable waterproof membrane. The difference from Example 1 is that in step S2, the modified filler has a weight ratio of 35 parts, while the other operating steps and process parameters are exactly the same as in Example 1.

[0148] Comparative Example 4

[0149] This comparative example provides an environmentally friendly biodegradable waterproof membrane. The difference from Example 1 is that in step S2, the modified filler has a weight ratio of 15 parts, while the other operating steps and process parameters are exactly the same as in Example 1.

[0150] The performance of the environmentally friendly biodegradable waterproof membranes of Examples 1-4 and Comparative Examples 1-4 was tested, and the specific process is as follows:

[0151] The samples were tested according to GB / T 328.1-2007 Test Methods for Waterproofing Membranes in Buildings;

[0152] The test results are shown in Table 1.

[0153] Table 1: Performance test results of environmentally friendly biodegradable waterproof membranes in Examples 1-4 and Comparative Examples 1-4

[0154]

[0155] As shown in Table 1, the environmentally friendly biodegradable waterproof membranes prepared in Examples 1-4 of this invention have good waterproof and mechanical properties.

[0156] The test results of Example 1 and Comparative Examples 1 and 2 show that when the amount of modified silica nanoparticles added is too large, they are easily dispersed unevenly, increasing local stress concentration, which in turn leads to a decrease in the flexibility of the functional layer, causing the roll material to crack easily and affecting its service life. When the amount added is too small, the mechanical strength and hydrophobicity of the waterproof layer may decrease, leading to an increased risk of water penetration. At the same time, the weather resistance deteriorates, shortening the life of the roll material.

[0157] The test results of Example 1 and Comparative Examples 3 and 4 show that when the amount of modified filler added is too high, the viscosity of the system will be too high, affecting the processing performance. In addition, the interface between the filler and the polymer matrix will be poor, thereby reducing the overall strength and toughness, resulting in increased brittleness and easy cracking of the roll material. When the amount added is too low, the hydrophobicity and weather resistance of the functional layer will decrease, resulting in insufficient performance of the roll material.

[0158] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An environmentally friendly biodegradable waterproof membrane, characterized in that, It includes a reinforcing layer, a waterproof functional layer, and a surface protective layer; wherein the reinforcing layer, the waterproof functional layer, and the surface protective layer are stacked sequentially. The reinforcing layer comprises bio-based fibers, natural fibers, binders, and hydrophobic modifiers; The waterproof functional layer comprises a bio-based polymer, modified silica nanoparticles, modified fillers, toughening agents, and antioxidants. The surface protective layer includes fluorinated polyurethane, silicone resin, fatty acid-coated reflective material, antioxidant, ultraviolet absorber and hydrophobic modifier; The bio-based fiber is polylactic acid fiber; The natural fiber is flax fiber or bamboo fiber; The bio-based polymer is polylactic acid or polybutylene succinate; The modified filler is prepared by the following process: montmorillonite and bentonite are dispersed in a bio-based cationic surfactant solution to modify the mixed filler, which is then added to a regenerated cellulose solution and polyvinylpyrrolidone is added to treat the mixture and obtain the modified filler. The reinforcing layer comprises the following components in parts by weight: 40-50 parts of bio-based fiber; 30-40 parts natural fiber; 15-25 parts adhesive; 5-10 parts of hydrophobic modifier; The adhesive is polyvinyl alcohol or starch glue; The hydrophobic modifier is any one or a combination of at least two of stearic acid, sodium stearate, and zinc stearate; The waterproof functional layer comprises the following components in parts by weight: 60-80 parts of bio-based polymer; 8-15 parts of modified silica nanoparticles; 20-30 parts of modified filler; 1-5 parts toughening agent; Antioxidant 1-3 parts; The toughening agent is glycerol or polyethylene glycol; The antioxidant is any one or a combination of at least two of vitamin E, antioxidant 1010, and antioxidant 1076.

2. The environmentally friendly biodegradable waterproof membrane according to claim 1, characterized in that, The surface protective layer comprises the following components in parts by weight: 40-60 parts of fluorinated polyurethane; 10-30 parts of silicone resin; 5-20 parts of fatty acid-coated reflective material; Antioxidant 0.5-2 parts; 0.5-2 parts of ultraviolet absorber; 0.5-3 parts of hydrophobic modifier; The reflective material in the fatty acid-coated reflective material is any one or a combination of at least two of zirconium oxide, titanium dioxide, and zinc oxide. The ultraviolet absorber is any one or a combination of at least two of the following: ultraviolet absorber UV-326, ultraviolet absorber UV-328, ultraviolet absorber UV-327, and ultraviolet absorber UV-531.

3. A method for preparing an environmentally friendly biodegradable waterproof membrane according to any one of claims 1 to 2, characterized in that, The preparation method includes: S1: Bio-based fibers and natural fibers are pretreated and dispersed in a binder solution to obtain mixed solution A. A hydrophobic modifier is added to obtain mixed solution B. The mixture is ultrasonically dispersed and stirred to obtain a slurry. The reinforcing layer is obtained through a wet molding process. S2: Modified mixed filler is obtained by dispersing montmorillonite and bentonite in a bio-based cationic surfactant solution, adding it to a regenerated cellulose solution, and adding polyvinylpyrrolidone for further treatment to obtain the modified filler. Modified silica nanoparticles were obtained by dispersing silica nanoparticles in a stearic acid ethanol solution. A waterproof functional layer is obtained by mixing bio-based polymers, modified silica nanoparticles, modified fillers, toughening agents, and antioxidants, melt blending, casting, and then thermosetting. S3: Fluorinated polyurethane is obtained by modifying polyurethane prepolymer with perfluorooctyltriethoxysilane; fatty acid-coated reflective material is obtained by modifying reflective material with palmitic acid solution; after mixing fluorinated polyurethane and silicone resin, fatty acid-coated reflective material, antioxidant, ultraviolet absorber and hydrophobic modifier are added in sequence and mixed evenly to obtain surface protective coating. S4: After cleaning the contact surfaces of the reinforcing layer and the waterproof functional layer, they are stacked and placed in a hot press for lamination. After completion, the composite material is obtained by keeping it in a pressed state and allowing it to cool naturally to room temperature. The surface protective coating is then applied to the surface of the waterproof functional layer and baked to cure, resulting in an environmentally friendly biodegradable waterproof membrane.

4. The method for preparing an environmentally friendly biodegradable waterproof membrane according to claim 3, characterized in that, In S1: the concentration of the adhesive is 0.1-0.2 g / mL.

5. The method for preparing an environmentally friendly biodegradable waterproof membrane according to claim 3, characterized in that, In S2: The mass ratio of montmorillonite to bentonite is (1-2):1; The bio-based cationic surfactant solution has a mass fraction of 2-5 wt.%. The total mass ratio of the bio-based cationic surfactant to montmorillonite and bentonite is 1:(15-25); The mass ratio of the modified mixed filler to regenerated cellulose is (5-10):1; The regenerated cellulose solution has a mass fraction of 5-10 wt.%. The amount of polyvinylpyrrolidone fed into the regenerated cellulose is 2-5 wt.%.

6. The method for preparing an environmentally friendly biodegradable waterproof membrane according to claim 3, characterized in that, In S2: the mass ratio of the silica nanoparticles to stearic acid is (10-20):1; The stearic acid ethanol solution has a mass fraction of 1-5 wt.%.

7. The method for preparing an environmentally friendly biodegradable waterproof membrane according to claim 3, characterized in that, In S3: The mass ratio of perfluorooctyltriethoxysilane to polyurethane prepolymer is 1:(5-10). The concentration of the palmitic acid solution is 0.1-0.5 mol / L; The mass ratio of the reflective material to the palmitic acid solution is 1:(10-20).

8. The method for preparing an environmentally friendly biodegradable waterproof membrane according to claim 3, characterized in that, In S4: The temperature at which the reinforcing layer and the waterproof functional layer are bonded together in the hot press is 150-180℃. The pressure at which the reinforcing layer and the waterproof functional layer are bonded together in the hot press is 5-10 MPa. The bonding time between the reinforcing layer and the waterproof functional layer in the hot press is 10-20 minutes. The baking and curing temperature is 80-100℃; The baking and curing time is 20-30 minutes.

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