Self-repairing modified asphalt waterproof coiled material and preparation method thereof
By combining TiO2N-CQDS composite with asphalt matrix and modifying with graphene nanosheets, the problem of self-repair and performance improvement of asphalt waterproof membrane in low-temperature environment was solved, achieving self-healing and performance enhancement.
Patent Information
- Application Number
- CN202510966752.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-14
- Publication Date
- 2025-10-28
AI Technical Summary
Traditional bitumen waterproof membranes age and become brittle due to environmental factors during long-term service, resulting in decreased flexibility and an inability to repair micro-cracks on their own, which affects their waterproof performance and structural integrity.
By combining TiO2N-CQDS composite with an asphalt matrix, the self-healing ability of the material is enhanced through the synergistic effect of chemical bonding and photocatalysis. Graphene nanosheets are added to form a three-dimensional conductive network to improve performance.
It achieves self-healing of microcracks in low-temperature environments, enhances ultraviolet shielding capabilities, and improves the mechanical properties and environmental characteristics of materials, which are significantly superior to traditional roll materials.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of waterproof membrane technology, specifically to a self-healing modified bitumen waterproof membrane and its preparation method. Background Technology
[0002] Traditional bitumen-based waterproof membranes have inherent performance defects during long-term service: environmental factors such as ultraviolet radiation, temperature cycling, and oxidation inevitably lead to bitumen aging and embrittlement, reducing its flexibility and significantly shortening its effective service life. Especially in low-temperature environments, the increased brittleness of bitumen materials makes them highly susceptible to microcracks under stress. Once these microcracks form, they continue to propagate, ultimately damaging the material's waterproof performance and structural integrity.
[0003] Existing asphalt modification technologies, such as modification with styrene-butadiene-styrene block copolymer (SBS) or atactic polypropylene (APP), can improve the flexibility of asphalt to some extent, but these materials themselves do not have the ability to self-repair existing damage. Therefore, the accumulation of microcracks remains the main cause of the eventual failure of traditional asphalt materials.
[0004] Nano-titanium dioxide (TiO2) has photocatalytic properties, but it tends to accelerate asphalt aging when used alone. Carbon quantum dots (CQDS) have excellent photothermal conversion capabilities, but current technologies have not yet combined them with TiO2 for asphalt modification. Summary of the Invention
[0005] To overcome the problems in the prior art, this invention proposes a nano-TiO2N-CQDS composite modified bitumen waterproof membrane with low-temperature self-healing function, enabling it to achieve self-healing of microcracks in environments ranging from -20℃ to 10℃, while also enhancing its UV shielding ability. Addressing the issues of poor weather resistance and inability to self-repair micro-damage in existing bitumen waterproof membranes, this invention provides a modification method that achieves long-term protection and self-healing of cracks through the synergistic effects of nano-titanium dioxide surface modification, chemical bonding, and photocatalysis, while simultaneously improving its mechanical properties and environmental characteristics.
[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: A self-healing modified bitumen waterproof membrane, comprising: The TiO2N-CQDS composite is formed by combining anatase nano-TiO2 and nitrogen-doped carbon quantum dots N-CQDS in a mass ratio of 1:0.5 through carboxyl coordination bonds. The asphalt matrix contains TiO2N-CQDS and sulfur. The base material is a glass fiber reinforced polyester base material with a porous TPU film covering its surface.
[0007] Furthermore, the amount of TiO2N-CQDS added to the asphalt matrix is 4% of the mass of the asphalt matrix.
[0008] Furthermore, the amount of sulfur added to the asphalt matrix is 1.5% of the mass of the asphalt matrix.
[0009] Furthermore, it also includes graphene nanosheets, with a content of 0.5-2% of the mass of the asphalt matrix.
[0010] A method for preparing a self-healing modified bitumen waterproof membrane includes the following steps: S1. N-CQDS and nano-TiO2 were sonicated in an ethanol solution at 40 kHz for 30 min, and then dried by centrifugation to obtain the TiO2N-CQDS composite. S2. Surface modification: The TiO2N-CQDS composite was dispersed in anhydrous ethanol with a solid content of 10%; a silane coupling agent was added, accounting for 5% of the mass of TiO2; the mixture was stirred at 80°C for 2 hours, centrifuged and dried. S3. Asphalt pretreatment: Heat the base asphalt to 160±5℃, add 1% by mass of hindered phenolic antioxidant, and stir at 500rpm for 30 minutes. S4, Composite Modification Preparation: The modified TiO2 prepared in S2 is added to the pretreated asphalt in S3 at 6-10% of the asphalt mass. It is first dispersed by high-speed shearing at 3000 rpm for 1 hour, and then ultrasonically treated at 40 kHz for 20 minutes. Then, graphene nanosheets are added and stirring is continued for 30 minutes. S5. Roll forming: S3 modified bitumen is coated onto the polyester base with a thickness of 1.5mm, calendered at 150℃ using two rollers, cooled to 50℃, covered with PE film, and then cut into shape.
[0011] The beneficial effects of this invention are: 1. Excellent low-temperature self-healing performance is achieved: Silane coupling agents (such as γ-methacryloyloxypropyltrimethoxysilane, KH-570) are used to graft nano-TiO2 (particle size 5-10nm) onto the surface, so that it forms chemical bonds with polar groups (such as carboxyl groups and hydroxyl groups) in asphalt, thereby enhancing compatibility and dispersion stability.
[0012] 2. Photocatalytic self-healing mechanism: Under sunlight or ultraviolet light irradiation, nano-TiO2 catalyzes the decomposition of asphalt aging products (such as carbonyl compounds), while promoting the reconstruction and cross-linking of asphalt molecular chains, thus achieving self-healing of microcracks; in addition, the absorption of ultraviolet light by TiO2 effectively inhibits the photoaging of asphalt.
[0013] 3. Multifunctional synergistic modification: Introducing graphene nanosheets (0.5-2% by mass) and nano-TiO2 composites to form a three-dimensional conductive network, enhancing the thermal conductivity and antistatic properties of asphalt, suitable for special scenarios such as photovoltaic roofs. Detailed Implementation
[0014] To make the objectives, technical solutions, and beneficial effects of the present invention clearer, the preferred embodiments of the present invention will be described in detail below to facilitate understanding by those skilled in the art.
[0015] Example 1 This embodiment provides a self-healing modified bitumen waterproof membrane, comprising: The TiO2N-CQDS composite is formed by combining anatase nano-TiO2 and nitrogen-doped carbon quantum dots N-CQDS in a mass ratio of 1:0.5 through carboxyl coordination bonds. 100 parts of asphalt matrix, wherein TiO2N-CQDS and sulfur are added to the asphalt matrix; the amount of TiO2N-CQDS added to the asphalt matrix is 4 parts, and the amount of sulfur added to the asphalt matrix is 1.5 parts. The base material is a glass fiber reinforced polyester base material with a porous TPU film covering the surface, the pore size being 5-20 μm. And it is prepared through the following steps: S1. N-CQDS and nano-TiO2 were sonicated in an ethanol solution at 40 kHz for 30 min, and then dried by centrifugation to obtain the TiO2N-CQDS composite. S2. Surface modification: The TiO2N-CQDS composite was dispersed in anhydrous ethanol with a solid content of 10%; 0.2‰ mass fraction of silane coupling agent KH-570 was added to the asphalt matrix; the mixture was stirred at 80℃ for 2 hours, centrifuged and dried. S3. Asphalt pretreatment: Heat the base asphalt to 160±5℃, add 1 part of hindered phenolic antioxidant BHT, and stir at high speed of 500rpm for 30 minutes. S4, Composite Modification Preparation: Add the modified TiO2 prepared in S2 to the pretreated asphalt in S3 at 6-10% of the asphalt mass. First, disperse it by high-speed shearing at 3000 rpm for 1 hour, then treat it with ultrasonic treatment at 40 kHz for 20 minutes, and continue stirring for 30 minutes. S5. Roll forming: S3 modified bitumen is coated onto the polyester base with a thickness of 1.5mm, calendered at 150℃ using two rollers, cooled to 50℃, covered with PE film, and then cut into shape.
[0016] Example 2 A self-healing modified bitumen waterproof membrane is prepared by adding 1 part of graphene nanosheets based on Example 1. In S4, the composite modification preparation is carried out by adding the modified TiO2 prepared in S2 to the pretreated bitumen in S3 at 4% of the bitumen mass. The mixture is first dispersed by high-speed shearing at 3000 rpm for 1 hour, then ultrasonically treated at 40 kHz for 20 minutes, and then 1 part of graphene nanosheets is added and stirred for another 30 minutes.
[0017] Comparative Example 1 Using commercially available conventional asphalt rolls Performance testing The waterproof membranes prepared in Examples 1 and 2 were compared with those in Comparative Example 1. The results are shown in Tables 1, 2 and 3.
[0018] Table 1 Performance Test Table
[0019] Table 2 Self-repair test
[0020] Table 3 Mechanical Properties
[0021] Data Analysis: As shown in the comparative data in Tables 1-3, the waterproof membranes prepared in Examples 1 and 2 of this invention are significantly superior to traditional asphalt membranes (Comparative Example 1) in many aspects, including joint peel strength, UV aging resistance, self-healing efficiency, thermal conductivity, heat resistance, and low-temperature bending performance. In particular, the product of this invention still exhibits highly efficient self-healing ability at a low temperature of -10℃, a function that traditional membranes do not possess.
[0022] In summary, this invention represents a technological breakthrough and provides an effective technical solution for addressing the challenges of durability and self-healing of asphalt waterproof membranes in complex environments.
[0023] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.
Claims
1. A self-healing modified bitumen waterproof membrane, characterized in that, include: The TiO2N-CQDS composite is formed by combining anatase nano-TiO2 and nitrogen-doped carbon quantum dots N-CQDS through carboxyl coordination bonds. The asphalt matrix contains TiO2N-CQDS and sulfur. Tire base material.
2. The self-healing modified bitumen waterproof membrane according to claim 1, characterized in that, The mass ratio of TiO2 to N-CQDS is 1:0.
5.
3. The self-healing modified bitumen waterproof membrane according to claim 1, characterized in that, The amount of TiO2N-CQDS added to the asphalt matrix is 4% of the mass of the asphalt matrix.
4. The self-healing modified bitumen waterproof membrane according to claim 1, characterized in that, The amount of sulfur added to the asphalt matrix is 1.5% of the mass of the asphalt matrix.
5. The self-healing modified bitumen waterproof membrane according to claim 1, characterized in that, It also includes graphene nanosheets, with a content of 0.5-2% of the mass of the asphalt matrix.
6. A method for preparing a self-healing modified bitumen waterproof membrane as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. N-CQDS and nano-TiO2 were sonicated in an ethanol solution at 40 kHz for 30 min, and then dried by centrifugation to obtain the TiO2N-CQDS composite. S2. Surface modification: The TiO2N-CQDS composite was dispersed in anhydrous ethanol with a solid content of 10%; a silane coupling agent was added, accounting for 5% of the mass of TiO2; the mixture was stirred at 80°C for 2 hours, centrifuged and dried. S3. Asphalt pretreatment: Heat the base asphalt to 160±5℃, add 1% by mass of hindered phenolic antioxidant, and stir at 500rpm for 30 minutes. S4, Composite Modification Preparation: The modified TiO2 prepared in S2 was added to the pretreated asphalt in S3 at 4% of the asphalt mass. It was first dispersed by high-speed shearing at 3000 rpm for 1 hour, and then ultrasonically treated at 40 kHz for 20 minutes. Graphene nanosheets were then added and stirred for another 30 minutes. S5. Roll forming: S3 modified bitumen is coated onto the polyester base with a thickness of 1.5mm, calendered at 150℃ using two rollers, cooled to 50℃, covered with PE film, and then cut into shape.