Self-repairing elastomer-modified asphalt waterproofing membrane and preparation method thereof

Abstract

The present invention discloses a self-repairing elastomer-modified asphalt waterproofing membrane and a preparation method thereof, and relates to the technical field of waterproofing membranes. The present invention utilizes bis(6-hydroxyhexyl) disulfide and 5-hexeneboronic acid to form a dual self-repairing compound, which is then reacted with a hydrogenated styrene thermoplastic elastomer, introduced between elastomer molecular chains, and used for an elastomer-modified asphalt waterproofing membrane. The fracture-rearrangement characteristics of dynamic disulfide bonds and borate ester bonds are utilized to achieve self-repair of fracture damage of the waterproofing membrane. In addition, the present invention utilizes a dual self-repairing compound to undergo a cross-linking reaction with a hydrogenated styrene thermoplastic elastomer, which is beneficial to improving the heat resistance and low-temperature flexibility of the modified asphalt waterproofing membrane. On the other hand, the C=C double bond content in the elastomer is reduced, which can effectively avoid problems such as chain scission degradation of the elastomer under the action of heat, ultraviolet rays and oxygen, thereby significantly improving the anti-aging properties of the modified asphalt waterproofing membrane.

Description

Technical Field

[0001] The present invention relates to the technical field of waterproof roll materials, and in particular to a self-repairing elastomer-modified asphalt waterproof roll material and a preparation method thereof. Background Art

[0002] Thermoplastic elastomer-modified asphalt waterproofing membranes have excellent high-temperature anti-flow and low-temperature anti-cracking properties and have been widely used in building waterproofing projects. However, during service, elastomer-modified asphalt waterproofing membranes will age and become brittle due to the effects of heat, oxygen, and ultraviolet rays, and thus easily crack under the action of external forces (such as deformation of the base layer), causing leakage in the building. Therefore, improving the weather resistance of elastomer-modified asphalt waterproofing membranes and giving them the ability to self-repair cracks are extremely important for solving the problem of building leakage. In recent years, polymer self-repair technology based on dynamic repair bonds has been widely studied and applied. Existing polymer materials based on dynamic self-healing usually use compounds with -0H, -COOH or -NH2 at both ends and compounds or prepolymers with isocyanate (-NCO) or amino (-NH2) at both ends as reactive monomers. Dynamic self-healing bonds are introduced into the polymer molecular chain through condensation reaction to give the polymer self-healing function. However, elastomers usually do not contain the above-mentioned reactive groups such as -NCO and -NH2. Further exploration of the efficient resource utilization of elastomers with self-healing function in fields such as waterproof membranes has important research and application significance. Summary of the Invention

[0003] The purpose of the present invention is to provide a self-repairing elastomer-modified asphalt waterproofing membrane and a preparation method thereof, so as to solve the problems existing in the prior art.

[0004] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing a self-repairing elastomer-modified asphalt waterproof membrane, comprising the following preparation steps:

[0005] (1) 5-Hexeneboronic acid and bis(6-hydroxyhexyl) disulfide were mixed, and toluene was added. The mixture was stirred at 100-110°C and 40 rpm for 8 h. The lower layer solution was separated by a water separation reflux device, and the upper layer solution was then heated to 8.8 × 10 4 The self-repairing modifier was obtained by vacuum distillation at Pa for 20 min;

[0006] (2) Mixing hydrogenated styrene thermoplastic elastomer and toluene, adding a self-healing modifier, heating to 60-65°C, adding benzoyl peroxide under nitrogen protection, stirring at 60-80 rpm for 5-8 hours, cooling to room temperature, adding ethanol until precipitation occurs, taking the precipitate, and drying it at 60°C for 1 hour to obtain a modified elastomer;

[0007] (3) 50 to 60 parts by mass of asphalt are heated to 180° C., 8 to 12 parts by mass of modified elastomer are added, and the mixture is stirred at 2000 rpm for 10 minutes to obtain modified asphalt. The modified asphalt is then transported to a coating machine and coated in the order of a lower isolation membrane layer, a lower modified asphalt layer, a matrix layer, an upper modified asphalt layer, and an upper isolation membrane layer to obtain a self-repairing elastomer-modified asphalt waterproof membrane.

[0008] Furthermore, the ratio of 5-hexeneboronic acid and toluene in step (1) is 1 mol:20 mL.

[0009] Furthermore, the molar ratio of 5-hexeneboronic acid to bis(6-hydroxyhexyl) disulfide in step (1) is 1:1.2-1.6.

[0010] Furthermore, the Shore hardness of the hydrogenated styrene-based thermoplastic elastomer in step (2) is ≤75A, and the melt index at 230°C and 5kg is ≥2g / 10min.

[0011] Furthermore, the hydrogenated styrene-based thermoplastic elastomer in step (2) is one or both of hydrogenated styrene-butadiene block copolymer (SEBS) and hydrogenated styrene-isoprene block copolymer (SEPS).

[0012] Furthermore, in step (2), the hydrogenated styrene-based thermoplastic elastomer is 80 to 100 parts by mass, toluene is 520 parts by mass, the self-healing modifier is 8 to 10 parts by mass, and benzoyl peroxide is 0.1 to 0.3 parts by mass.

[0013] Furthermore, the softening point of the asphalt in step (3) is 46.3°C, and the needle penetration at 25°C is 89 dmm.

[0014] Furthermore, the upper and lower isolation film layers in step (3) are PET single-sided silicone oil isolation films with a thickness of 0.1 to 1 mm.

[0015] Furthermore, the matrix layer in step (3) is polyester non-woven fabric with a thickness of 1.0 to 1.6 mm.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention utilizes the reaction of the hydroxyl group of bis(6-hydroxyhexyl) disulfide with the hydroxyl group of 5-hexeneboronic acid to form a double self-healing compound containing a C=C double bond at the molecular chain end, which is then reacted with a hydrogenated styrene thermoplastic elastomer. Under the action of an initiator, the C=C double bond in the double self-healing compound reacts with the C=C double bond in the hydrogenated styrene thermoplastic elastomer, and dynamic disulfide bonds and borate bonds are introduced between the elastomer molecular chains. The compound is used in an elastomer-modified asphalt waterproofing membrane, and the fracture-rearrangement characteristics of the dynamic disulfide bonds and borate bonds are utilized. When the elastomer-modified asphalt waterproofing membrane is formed, When subjected to external force, the dynamic disulfide bonds and borate bonds are broken first. After the external force is eliminated, the broken disulfide bonds and borate bonds are rearranged to restore the original molecular structure, thereby realizing the self-repair of the broken and damaged waterproof membrane; in addition, the present invention utilizes dual self-repairing compounds to undergo cross-linking reactions with hydrogenated styrene thermoplastic elastomers, which is beneficial to improving the heat resistance and low-temperature flexibility of the modified asphalt waterproof membrane. On the other hand, it reduces the C=C double bond content in the elastomer, which can effectively avoid problems such as chain breakage and degradation of the elastomer under the action of heat, ultraviolet rays and oxygen, thereby significantly improving the aging resistance of the modified asphalt membrane. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] In order to more clearly illustrate the method provided by the present invention, the following examples are used to describe in detail the various index testing methods of the asphalt waterproofing membranes prepared in the following examples.

[0020] Self-healing performance: The modified asphalt waterproofing membrane was bent around a 30mm diameter rod at a temperature below its ultimate low-temperature flexibility, creating cracks on the modified asphalt surface. The cracked low-temperature flexible specimen was placed horizontally at 26±2°C for 12 hours. The ultimate low-temperature flexibility was then tested, and the self-healing rate of the self-healing elastomer-modified asphalt coating was calculated. Self-healing rate = ultimate low-temperature flexibility after healing / initial ultimate low-temperature flexibility × 100%.

[0021] Material limit low temperature flexibility: Test the low temperature flexibility of waterproof membrane according to "Test methods for building waterproof membranes Part 14: Low temperature flexibility of asphalt waterproof membranes" (GB / T328.14-2007), gradually lower or increase the test temperature until only one of the five specimens has cracks, which is called the limit low temperature flexibility.

[0022] Example 1

[0023] (1) 5-Hexeneboronic acid and bis(6-hydroxyhexyl) disulfide were mixed in a molar ratio of 1:1.2, and toluene was added at a ratio of 1 mol:20 mL of 5-hexeneboronic acid to toluene. The mixture was stirred at 100°C and 40 rpm for 8 h. The lower layer solution was separated by a water separation reflux device, and the upper layer solution was then heated to 8.8 × 10 4 The self-repairing modifier was obtained by vacuum distillation at Pa for 20 min;

[0024] (2) 80 parts by mass of hydrogenated styrene-butadiene block copolymer and 520 parts by mass of toluene were mixed, and then 8 parts by mass of a self-healing modifier was added, and the mixture was heated to 60°C. Under nitrogen protection, 0.1 parts by mass of benzoyl peroxide was added, and the mixture was stirred at 60 rpm for 5 hours. After cooling to room temperature, ethanol was added until precipitation occurred. The precipitate was taken and dried at 60°C for 1 hour to obtain a modified elastomer;

[0025] (3) 50 parts by mass of asphalt were heated to 180°C, 8 parts by mass of modified elastomer were added, and the mixture was stirred at 2000 rpm for 10 minutes to obtain modified asphalt. The modified asphalt was then transported to a coating machine and coated in the order of a lower isolation film layer, a lower modified asphalt layer, a matrix layer, an upper modified asphalt layer, and an upper isolation film layer to obtain a self-repairing elastomer modified asphalt waterproofing membrane; the matrix layer was a polyester non-woven fabric with a thickness of 1.3 mm; the upper and lower isolation film layers were PET single-sided silicone oil isolation films with a thickness of 0.5 mm.

[0026] Example 2

[0027] (1) 5-Hexeneboronic acid and bis(6-hydroxyhexyl) disulfide were mixed in a molar ratio of 1:1.6, and toluene was added in a ratio of 5-hexeneboronic acid to toluene of 1 mol:20 mL. The mixture was stirred at 110°C and 40 rpm for 8 h. The lower layer solution was separated by a water separation reflux device, and the upper layer solution was then heated to 8.8 × 10 4 The self-repairing modifier was obtained by vacuum distillation at Pa for 20 min;

[0028] (2) 100 parts by mass of hydrogenated styrene-isoprene block copolymer and 520 parts by mass of toluene were mixed, and then 10 parts by mass of a self-healing modifier was added, and the mixture was heated to 65°C. Under nitrogen protection, 0.3 parts by mass of benzoyl peroxide was added, and the mixture was stirred at 80 rpm for 8 hours. After cooling to room temperature, ethanol was added until precipitation occurred. The precipitate was taken and dried at 60°C for 1 hour to obtain a modified elastomer;

[0029] (3) 60 parts by mass of asphalt were heated to 180° C., 12 parts by mass of modified elastomer were added, and the mixture was stirred at 2000 rpm for 10 min to obtain modified asphalt. The modified asphalt was then transported to a coating machine and coated in the order of a lower isolation film layer, a lower modified asphalt layer, a matrix layer, an upper modified asphalt layer, and an upper isolation film layer to obtain a self-repairing elastomer modified asphalt waterproofing membrane; the matrix layer was a polyester non-woven fabric with a thickness of 1.3 mm; the upper and lower isolation film layers were PET single-sided silicone oil isolation films with a thickness of 0.5 mm.

[0030] Example 3

[0031] (1) 5-Hexeneboronic acid and bis(6-hydroxyhexyl) disulfide were mixed in a molar ratio of 1:1.4, and toluene was added at a ratio of 1 mol:20 mL of 5-hexeneboronic acid to toluene. The mixture was stirred at 105°C and 40 rpm for 8 h. The lower layer solution was separated by a water separation reflux device, and the upper layer solution was then heated to 8.8 × 10 4 The self-repairing modifier was obtained by vacuum distillation at Pa for 20 min;

[0032] (2) 90 parts by mass of hydrogenated styrene-butadiene block copolymer and 520 parts by mass of toluene were mixed, and then 9 parts by mass of a self-healing modifier was added, and the mixture was heated to 65° C. Under nitrogen protection, 0.2 parts by mass of benzoyl peroxide was added, and the mixture was stirred at 70 rpm for 8 hours. After cooling to room temperature, ethanol was added until precipitation occurred. The precipitate was taken and dried at 60° C. for 1 hour to obtain a modified elastomer;

[0033] (3) 55 parts by mass of asphalt were heated to 180° C., 10 parts by mass of modified elastomer were added, and the mixture was stirred at 2000 rpm for 10 min to obtain modified asphalt. The modified asphalt was then transported to a coating machine and coated in the order of a lower isolation film layer, a lower modified asphalt layer, a matrix layer, an upper modified asphalt layer, and an upper isolation film layer to obtain a self-repairing elastomer modified asphalt waterproofing membrane; the matrix layer was a polyester non-woven fabric with a thickness of 1.3 mm; the upper and lower isolation film layers were PET single-sided silicone oil isolation films with a thickness of 0.5 mm.

[0034] Comparative Example 1

[0035] The difference between Comparative Example 1 and Example 2 is that step (1) is omitted, and step (2) is modified as follows: 100 parts by mass of hydrogenated styrene-isoprene block copolymer and 520 parts by mass of toluene are mixed, 10 parts by mass of 5-hexeneboric acid are added, and the mixture is heated to 65° C., 0.3 parts by mass of benzoyl peroxide is added under nitrogen protection, and the mixture is stirred at 80 rpm for 8 h. After cooling to room temperature, ethanol is added until a precipitate is precipitated, and the precipitate is taken and dried at 60° C. for 1 h to obtain a modified elastomer; the remaining steps are the same as those in Example 2.

[0036] Comparative Example 2

[0037] The difference between Comparative Example 2 and Example 2 is that there is no step (2), and step (3) is changed to: 60 parts by mass of asphalt are heated to 180°C, 12 parts by mass of hydrogenated styrene-isoprene block copolymer and 0.1 parts by mass of self-healing modifier are added, and stirred at 2000rpm for 10 minutes to obtain modified asphalt, and then the modified asphalt is transported to the coating machine, and coated in the order of lower isolation film layer, lower modified asphalt layer, matrix layer, upper modified asphalt layer, and upper isolation film layer to obtain a self-healing elastomer modified asphalt waterproof membrane; the matrix layer is a polyester non-woven fabric with a thickness of 1.3mm; the upper and lower isolation film layers are PET single-sided silicone oil isolation films with a thickness of 0.5mm.

[0038] Comparative Example

[0039] Effect Examples

[0040] Table 1 below shows the performance analysis results of the asphalt waterproof membranes of Examples 1 to 3 of the present invention and Comparative Examples 1 to 2.

[0041] Table 1

[0042]

[0043] The present invention utilizes the reaction of the hydroxyl group of bis(6-hydroxyhexyl) disulfide with the hydroxyl group of 5-hexeneboronic acid to form a double self-healing compound containing a C=C double bond at the molecular chain end, which is then reacted with a hydrogenated styrene thermoplastic elastomer. Under the action of an initiator, the C=C double bond in the double self-healing compound reacts with the C=C double bond in the hydrogenated styrene thermoplastic elastomer, and dynamic disulfide bonds and borate bonds are introduced between the elastomer molecular chains. The compound is used in an elastomer-modified asphalt waterproofing membrane, and the fracture-rearrangement characteristics of the dynamic disulfide bonds and borate bonds are utilized. When the elastomer-modified asphalt waterproofing membrane is formed, When subjected to external force, the dynamic disulfide bonds and borate bonds are broken first. After the external force is eliminated, the broken disulfide bonds and borate bonds are rearranged to restore the original molecular structure, thereby realizing the self-repair of the broken and damaged waterproof membrane; in addition, the present invention utilizes dual self-repairing compounds to undergo cross-linking reactions with hydrogenated styrene thermoplastic elastomers, which is beneficial to improving the heat resistance and low-temperature flexibility of the modified asphalt waterproof membrane. On the other hand, it reduces the C=C double bond content in the elastomer, which can effectively avoid problems such as chain breakage and degradation of the elastomer under the action of heat, ultraviolet rays and oxygen, thereby significantly improving the aging resistance of the modified asphalt membrane.

[0044] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed therein. Any reference in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A method for preparing a self-repairing elastomer-modified asphalt waterproof membrane, characterized in that: The method comprises the following preparation steps: (1) 5-Hexeneboronic acid and bis(6-hydroxyhexyl) disulfide were mixed in a molar ratio of 1:1.2~1.6, and then toluene was added. The mixture was stirred at 100~110℃ and 40rpm for 8h. The lower layer solution was separated by a water separation reflux device, and the upper layer solution was then heated to 8.8×10 4 The self-repairing modifier was obtained by vacuum distillation at Pa for 20 min; (2) 80-100 parts by mass of hydrogenated styrene thermoplastic elastomer and 520 parts by mass of toluene were mixed, and then 8-10 parts by mass of self-healing modifier were added, and the mixture was heated to 60-65°C. Under nitrogen protection, 0.1-0.3 parts by mass of benzoyl peroxide was added, and the mixture was stirred at 60-80 rpm for 5-8 hours. After cooling to room temperature, ethanol was added until precipitation occurred. The precipitate was taken and dried at 60°C for 1 hour to obtain a modified elastomer. (3) Heat 50-60 parts by mass of asphalt to 180°C, add 8-12 parts by mass of modified elastomer, and stir at 2000 rpm for 10 minutes to obtain modified asphalt. Then, transport the modified asphalt to a coating machine and coat it in the order of lower isolation membrane layer, lower modified asphalt layer, matrix layer, upper modified asphalt layer, and upper isolation membrane layer to obtain a self-repairing elastomer modified asphalt waterproof membrane.

2. The method for preparing a self-repairing elastomer-modified asphalt waterproof membrane according to claim 1, characterized in that: The ratio of 5-hexeneboronic acid and toluene in step (1) is 1 mol:20 mL.

3. The method for preparing a self-repairing elastomer-modified asphalt waterproof membrane according to claim 1, characterized in that: The hydrogenated styrene-based thermoplastic elastomer in step (2) has a Shore hardness of ≤75A and a melt index of ≥2g / 10min at 230°C and 5kg.

4. The method for preparing a self-repairing elastomer-modified asphalt waterproof membrane according to claim 1, characterized in that: The hydrogenated styrene-based thermoplastic elastomer in step (2) is one or both of hydrogenated styrene-butadiene block copolymer (SEBS) and hydrogenated styrene-isoprene block copolymer (SEPS).

5. The method for preparing a self-repairing elastomer-modified asphalt waterproof membrane according to claim 1, characterized in that: The softening point of the asphalt in step (3) is 46.3°C, and the needle penetration at 25°C is 89 dmm.

6. The method for preparing a self-repairing elastomer-modified asphalt waterproof membrane according to claim 1, characterized in that: The upper and lower isolation film layers in step (3) are PET single-sided silicone oil isolation films with a thickness of 0.1~1mm.

7. The method for preparing a self-repairing elastomer-modified asphalt waterproof membrane according to claim 1, characterized in that: The matrix layer in step (3) is polyester non-woven fabric with a thickness of 1.0-1.6 mm.

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