Modified asphalt waterproofing membrane and method for preparing the same

Abstract

The present application relates to waterproofing membrane technical field, specifically to a kind of modified bitumen waterproofing membrane and preparation method thereof.The waterproofing membrane prepared by the present application overcomes the problem of poor mechanical properties and poor adhesion of asphalt membrane in the prior art.The modified bitumen waterproofing membrane is prepared by pre-impregnation roller pressing of the composite base obtained by roller pressing of modified glass fiber and base and modified bitumen, drying and curing.The amount of diisocyanate and hydroxyl-terminated polydimethylsiloxane is controlled to improve the high-temperature resistance and low-temperature resistance of the waterproofing membrane.The amount of modified polyurethane is controlled to improve the mechanical properties of the membrane.The amount of modified bitumen and composite base is changed to improve the peel strength of the membrane and the adhesion of the membrane.

Description

Technical Field

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

[0002] Membrane refers to a continuous roll of base material, mainly used in building walls, roofs, tunnels, roads and landfills. It is a flexible building material product that can be rolled into a roll to prevent external rainwater and groundwater leakage. As a leak-proof connection between the project foundation and the building, it is the first barrier to waterproofing the entire project and plays a vital role in the entire project.

[0003] Currently, there are three main types of waterproofing materials in China: asphalt-based waterproofing membranes, polyurethane waterproofing materials, and new polymer cement-based waterproofing materials. These materials are categorized by their carcass type: non-carcass, paper-based, fiberglass-based, glass cloth-based, and polyethylene-based. However, asphalt-based waterproofing membranes generate significant amounts of waste gas during the preparation of asphalt, causing significant environmental pollution and being prone to burns, fires, and other accidents.

[0004] Modified asphalt waterproofing membranes are made by subjecting asphalt, softening oil, SBS, rubber powder, and additives to high-speed shearing at high temperatures. Non-woven fabric, jute cloth, and fiberglass felt are then impregnated into the modified asphalt as a base, and a plastic film is added as a barrier layer. Modified asphalt easily coagulates, and the rubber particles don't react completely, often leaving some small particles or lumps. This results in inadequate asphalt modification, making the resulting waterproofing membrane prone to cracking and poor waterproofing effectiveness.

[0005] Patent CN114316803B reports a modified asphalt waterproofing membrane and its preparation method. The waterproofing membrane uses styrene-butadiene rubber and modified phenolic resin to modify the asphalt, which can improve the stability and mechanical properties of the final waterproofing membrane to a certain extent. However, while the branched borate increases the branching degree, it reduces the waterproofing membrane's high-temperature and low-temperature resistance, making it susceptible to environmental influences.

[0006] Patent CN113914114B reports a modified asphalt waterproofing membrane and a preparation method thereof, comprising a modified asphalt layer, a base, a PET film, and mineral particles. The prepared modified asphalt waterproofing membrane has excellent waterproofing properties and stable cold and heat resistance. However, the modified asphalt waterproofing membrane prepared by this invention has low adhesion and decreased peel strength due to the poor compatibility of the modified asphalt layer.

[0007] Patent CN109456731B reports an SBS asphalt waterproofing membrane and a preparation method thereof. The membrane comprises an SBS membrane body and a slow bonding layer coated thereon, and a fast bonding layer coated on the slow bonding layer. The resulting waterproofing membrane has strong adhesion, is not prone to peeling after bonding, and has improved mechanical properties. However, the polymer used in the bonding layer is easily affected by natural factors such as heat, oxygen, and ultraviolet light and ages. At the same time, the introduction of a large amount of SBS further reduces the membrane's anti-aging ability.

[0008] In summary, although certain technical improvements have been made to asphalt waterproofing membranes in the prior art, there are still problems with the waterproofing membranes, such as insufficient mechanical properties and poor bonding properties, which lead to low adhesion and thus affect the overall service life of the membranes.

[0009] Therefore, a modified asphalt waterproofing membrane and a preparation method thereof are proposed. Summary of the Invention

[0010] The present invention aims to provide a modified asphalt waterproofing membrane and a preparation method thereof. Asphalt is modified by polycondensing hexamethylene diisocyanate with hydroxyl-terminated polydimethylsiloxane, chain extension, antioxidant end-capping, and epoxy resin modification to obtain a modified polyurethane. Glass fiber modified with acrylic emulsion is mixed with a base and roll-pressed to obtain a composite base. The composite base is pre-impregnated in modified asphalt and roll-pressed, followed by drying and curing to obtain a modified asphalt waterproofing membrane. The polyurethane reaction conditions are controlled to improve the high- and low-temperature resistance of the waterproofing membrane. Polar groups in the epoxy resin are utilized to provide intermolecular forces to improve the mechanical properties of the modified asphalt waterproofing membrane. Fluorine-containing compounds are used as functional monomers in the acrylic emulsion to improve the water resistance of the membrane. The peel strength and adhesion of the modified asphalt waterproofing membrane are increased by adjusting the amounts of the composite base and modified asphalt and the curing reaction temperature. Antioxidants are grafted into the main chain of the membrane to synergistically enhance the light shielding properties and aging resistance of the membrane with titanium dioxide particles.

[0011] To achieve the above object, the present invention provides the following technical solutions:

[0012] In one aspect, the present invention provides a method for preparing a modified asphalt waterproofing membrane, wherein the preparation of the modified asphalt waterproofing membrane comprises the following steps:

[0013] Asphalt was added into a reaction tank preheated at 150°C to melt, stirred for 15 minutes, then heated to 170°C and stirred for 20 minutes to obtain a mixture; 20-50 parts of modified polyurethane and 10 parts of isoprene latex were added to the mixture, stirred for 2 hours, and then 5 parts of graphene were added, the temperature was raised to 200°C, and stirred at 3500 rpm for 30 minutes to obtain a mixture; 3-8 parts of maleic anhydride were added to the mixture, and the mixture was stirred at 160°C for 1 hour to obtain modified asphalt.

[0014] The modified glass fiber is mixed with the front and back sides of a base at 160° C. and rolled to obtain a composite base; 30-60 parts of the composite base are pre-impregnated with the modified asphalt to obtain a pre-impregnated base; 250-400 parts of the modified asphalt are coated on the pre-impregnated base, and the roll material is dried at a drying temperature of 160° C. to 200° C. to obtain a roll material; the surface of the roll material is coated with a polypropylene film with a thickness of 2 mm, 30 parts of mineral particles and 3-10 parts of titanium dioxide are added to the outermost layer, and the roll material is cooled and formed to obtain the modified asphalt waterproof membrane;

[0015] 60-90 parts of diisocyanate, 30-60 parts of terminal hydroxyl polydimethylsiloxane, and 10 parts of butanediol are subjected to polycondensation and chain extension reaction to obtain a polyurethane prepolymer; an antioxidant is added to the polyurethane prepolymer to seal the end, and epoxy resin is modified to obtain the modified polyurethane;

[0016] Acrylonitrile, vinyl acetate, hydroxyethyl acrylate and 3-10 parts of functional monomers are stirred to prepare a pre-emulsion; glass fiber precursor and ammonium persulfate are added to the pre-emulsion to prepare the modified glass fiber.

[0017] Preferably, the tire base is selected from one of a polyester tire base, a polyamide tire base, and a glass fiber reinforced polyester tire base.

[0018] Preferably, the preparation of the polyurethane comprises the following steps:

[0019] Adding 2-(2-chlorophenyl)-4,6-diphenyl-1,3,5-triazine, 4-hydroxyphenylboric acid, tetrakistriphenylphosphine palladium, and cesium carbonate to 1,4-dioxane, and reacting at 100° C. for 6 hours to obtain a reaction solution; cooling the reaction solution, adding water and ethyl acetate to dilute, extracting and separating, distilling under reduced pressure, and drying to obtain the antioxidant;

[0020] The diisocyanate and the hydroxy-terminated polydimethylsiloxane were dried in a vacuum drying oven at 80° C. for 2 hours to obtain a dry raw material; the dry raw material was added to a four-necked flask and dissolved in DMF to obtain a solution system; the solution system was protected by nitrogen, heated to 50° C., and dibutyltin dilaurate was added and reacted for 3 hours to obtain a reaction system; 10 parts of butanediol were added to the reaction system and chain extended for 2 hours to obtain a polyurethane prepolymer;

[0021] The polyurethane prepolymer is cooled to 40° C., the antioxidant is added, and the mixture is reacted at 60° C. for 2 hours to obtain an intermediate; the intermediate is cooled to room temperature, triethylamine is added to neutralize the reaction system, and the mixture is reacted for 30 minutes to obtain a neutralization system; the epoxy resin and dibutyltin dilaurate are added to the neutralization system, and the mixture is reacted at 70° C. for 3 hours to obtain a reactant; the reactant is cooled and vacuum degassing is performed to obtain the modified polyurethane.

[0022] Preferably, the diisocyanate is selected from toluene diisocyanate, lysine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and terephthalylene diisocyanate.

[0023] Preferably, the epoxy resin is selected from one of E42, E44, E51, and E52; and the ratio of the epoxy resin to the polyurethane prepolymer is 1:3-10.

[0024] Preferably, the preparation of the pre-emulsion comprises the following steps:

[0025] Sodium lauryl sulfate was added to a four-necked flask, and then added to deionized water and stirred for 15 minutes to prepare a mixed emulsion; acrylonitrile, vinyl acetate, hydroxyethyl acrylate, and functional monomers were added to the mixed emulsion, and stirred for pre-emulsification for 30 minutes to prepare the pre-emulsion.

[0026] Preferably, the functional monomer is selected from the group consisting of perfluorooctyl ethyl acrylate, hexafluorobutyl methacrylate, methacrylic acid, and 2-(perfluorodecyl)ethyl methacrylate.

[0027] Preferably, the preparation of the modified glass fiber comprises the following steps:

[0028] The glass fiber is subjected to the steps of dewaxing and alkali treatment to obtain the glass fiber precursor; the ammonium persulfate and NaHCO3 are added to a four-necked flask, added into deionized water, stirred and dissolved, and stirred for 10 minutes at room temperature to obtain a pre-reaction liquid; the pre-reaction liquid is heated to 60°C, the glass fiber precursor is added, and stirred for 10 minutes to obtain a stirred liquid; the pre-emulsion is dropwise added to the stirred liquid, the temperature is raised to 80°C, and the reaction is carried out for 2 hours to obtain a reaction liquid; the reaction liquid is cooled, washed with deionized water, extracted with ethanol, and vacuum dried at 60°C to obtain a modified glass fiber.

[0029] Preferably, the average molecular weight of the hydroxy-terminated polydimethylsiloxane is selected from 1600-2800.

[0030] Preferably, the line speed of the prepreg before rolling is 25.5-35.5 m / min, the production speed is 30-40 m / min, and the line speed of the modified asphalt after rolling is 30.5-32.5 m / min.

[0031] Another aspect of the present invention provides a modified asphalt waterproofing membrane, which comprises modified asphalt, a base, modified glass fiber, mineral particles, and titanium dioxide; the modified asphalt waterproofing membrane is prepared by any of the methods described above.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1、The modified polyurethane is obtained by condensation, chain extension, antioxidant end capping and epoxy resin modification of hexamethylene diisocyanate and hydroxyl-terminated polydimethylsiloxane, the matrix asphalt is modified by the modified polyurethane, the heat resistance of the roll material is increased by Si-O bond, and the low temperature resistance of the roll material is effectively improved by the long chain flexible structure; the low temperature flexibility of the modified asphalt waterproof roll material prepared by controlling the amount of diisocyanate and hydroxyl-terminated polydimethylsiloxane is-42 DEG C, and the softening point is 153 DEG C.

[0034] 2、The crosslinking degree and hydrogen bond density of the epoxy resin and the polyurethane are increased, so that a fuzzy interface layer is formed between the soft and hard segments of the polyurethane, strong non-covalent bond attraction is formed between the soft and hard segments, and the tensile properties and elongation at break of the roll material are improved; the amount of epoxy resin and modified polyurethane is controlled, the transverse tensile strength of the modified asphalt waterproof roll material prepared is 1315 N / mm, the longitudinal tensile strength is 1228 N / mm, and the mechanical properties are obviously improved.

[0035] 3、The modified glass fiber is prepared by using perfluoro octyl ethyl acrylate as a functional monomer to prepare a pre-emulsion, and the modified glass fiber is mixed with a tire base to be rolled to prepare a composite tire base, the modified asphalt waterproof roll material is obtained by pre-impregnation and rolling of the composite tire base in the modified asphalt and drying and curing; a dense protective film is formed on the surface of the waterproof roll material by using fluorine atoms, the modified asphalt waterproof roll material prepared can reach 5.5 h impermeability under the condition of 0.3 MPa, and the water resistance is obviously improved.

[0036] 4、The compatibility of the modified polyurethane and the asphalt is improved, and the stability of the modified asphalt is improved by adjusting the amount of maleic anhydride, the crosslinking degree of the modified polyurethane and the modified glass fiber in the modified asphalt is improved by adjusting the amount of the composite tire base and the modified asphalt and changing the crosslinking and curing temperature, and the crosslinking network structure formed improves the peel strength of the roll material; the peel strength of the modified asphalt waterproof roll material is 3.28 N / mm by changing the amount of the modified asphalt and the composite tire base and controlling the drying and curing temperature, and the adhesion is obviously improved.

[0037] 5、The antioxidant is used as an end capping agent of the polyurethane, the antioxidant is introduced into the main chain of the modified asphalt, the influence of free radical molecules on the intermolecular force of the modified asphalt is reduced, and the anti-aging performance of the waterproof roll material is further improved by adding titanium dioxide particles; the strength retention rate of the modified asphalt waterproof roll material is 98.6% after 800 h irradiation at 80 DEG C, the low temperature flexibility is-35 DEG C, and the anti-aging performance is obviously improved. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The tensile strength and elongation at break results of examples 15-18 are shown in the graph. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments 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.

[0040] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or those recommended by the manufacturer. All reagents or instruments used, if the manufacturer is not specified, are commercially available conventional products.

[0041] See also Figure 1 The present invention provides a modified asphalt waterproofing membrane and a preparation method thereof. The technical solution is as follows: Example 1

[0042] To 5 ml of 1,4-dioxane were added 5 mmol of 2-(2-chlorophenyl)-4,6-diphenyl-1,3,5-triazine, 6 mmol of 4-hydroxyphenylboric acid, 0.02 mmol of tetrakistriphenylphosphine palladium, and 10 mmol of cesium carbonate, and the mixture was reacted at 100° C. for 6 h to obtain a reaction solution. The reaction solution was cooled, diluted with water and ethyl acetate, separated by extraction, distilled under reduced pressure, and dried to obtain an antioxidant.

[0043] 80 parts of toluene diisocyanate and 50 parts of hydroxy-terminated polydimethylsiloxane were dried at 80° C. for 2 hours in a vacuum drying oven to prepare a dry raw material; the dry raw material was added to a four-necked flask and dissolved in 2 ml of DMF to prepare a dissolving system; the dissolving system was protected by nitrogen, heated to 50° C., and 2 parts of dibutyltin dilaurate were added and reacted for 3 hours to prepare a reaction system; 10 parts of butanediol were added to the reaction system, and the reaction was carried out by heat preservation for 2 hours to prepare a polyurethane prepolymer.

[0044] 100 parts of the polyurethane prepolymer are cooled to 40° C., acetone is added to reduce the viscosity, 15 parts of the antioxidant are added, and the mixture is reacted at 60° C. for 2 hours to obtain an intermediate; the intermediate is cooled to room temperature, triethylamine is added to neutralize the reaction system at 200 r / min, and the mixture is reacted for 30 minutes to obtain a neutralization system; 20 parts of epoxy resin are added to the neutralization system, dibutyltin dilaurate is added at 200 r / min, and the mixture is reacted at 70° C. for 3 hours to obtain a reactant; the reactant is cooled and vacuum degassing is performed to obtain a modified polyurethane.

[0045] In parts, 60 parts of 90# asphalt are added to a reaction tank preheated at 150°C to facilitate its full melting, stirred for 15 minutes, then heated to 170°C and stirred for 20 minutes to obtain a mixture; 40 parts of the modified polyurethane and 10 parts of isoprene latex are added to the mixture, stirred for 2 hours, and then 5 parts of graphene are added, and stirring is continued for 30 minutes. The mixture is heated to 200°C and stirred at 3500 rpm for 30 minutes to obtain a mixture; 5 parts of maleic anhydride are added to the mixture, and the mixture is stirred at 160°C for 1 hour to obtain a modified asphalt.

[0046] 6 parts of sodium lauryl sulfate were added to a four-necked flask, and 50 ml of deionized water were added and stirred for 15 minutes to prepare a mixed emulsion; 50 parts of acrylonitrile, 20 parts of vinyl acetate, 10 parts of hydroxyethyl acrylate, and 8 parts of perfluoroalkylethyl acrylate were added to the mixed emulsion, stirred at 200 r / min, and pre-emulsified for 30 minutes to prepare a pre-emulsion.

[0047] The glass fiber is subjected to steps such as dewaxing and alkali treatment to obtain a glass fiber precursor; 3 parts of ammonium persulfate and a buffer agent NaHCO3 are added to a four-necked flask, added into 50 ml of deionized water, stirred and dissolved, and stirred at 200 rpm for 10 minutes at room temperature to obtain a pre-reaction liquid; the pre-reaction liquid is heated to 60°C under oil bath conditions, the glass fiber precursor is added, and stirred at 200 rpm for 10 minutes to obtain a stirred liquid; the pre-emulsion is slowly added dropwise to the stirred liquid, the temperature is raised to 80°C, and the reaction is carried out for 2 hours to obtain a reaction liquid; the reaction liquid is cooled, washed with deionized water, extracted with ethanol, and vacuum dried at 60°C to obtain a modified glass fiber.

[0048] The modified glass fiber is mixed with the front and back sides of the base at 160°C and rolled to obtain a composite base; 50 parts of the composite base are pre-impregnated with the modified asphalt to obtain a pre-impregnated base, 300 parts of the modified asphalt are coated on the pre-impregnated base, and rolled and dried at a drying temperature of 180°C to obtain a rolled material; a polypropylene film is coated on the surface of the rolled material with a coating thickness of 2 mm, 30 parts of mineral particles and 8 parts of titanium dioxide are added to the outermost layer, and the material is cooled and formed to obtain a modified asphalt waterproof membrane.

[0049] Examples 2-13 The preparation methods and parameter conditions are similar to those of Example 1, with the differences shown in Table 1.

[0050] Table 1 Variation of component dosage in Examples 1-13

[0051]

[0052] Comparative Example 1 The preparation method and parameter conditions are the same as those in Example 1, except that polyether diol is used instead of hydroxyl-terminated polydimethylsiloxane.

[0053] Example 14 High and low temperature resistance performance measurement

[0054] The low-temperature flexibility and softening point of the modified asphalt waterproofing membrane prepared from Example 1-13 and Comparative Example 1 were tested. The low-temperature flexibility and waterproofness were tested according to the standard GB18242-2008 "Elastomer modified asphalt waterproofing membrane"; the softening point was tested according to the standard GB / T 4507-2014 "Bitumen - Determination of softening point - Ring and ball method". The test results are shown in Table 2.

[0055] Table 2 Determination of high and low temperature resistance of Example 1-13 and Comparative Example 1

[0056]

[0057] From the results in Table 2, it can be seen that the low-temperature flexibility and softening point of the modified asphalt waterproofing membrane prepared from the modified polyurethane using polyether glycol instead of hydroxyl-terminated polydimethylsiloxane in Comparative Example 1 decreased obviously compared to Example 1-13, and the low-temperature resistance and high-temperature resistance of the membrane decreased. Due to the introduction of polysiloxane, the Si-O bond with high bond energy was introduced into the polyurethane molecular backbone, which further increased the heat resistance of the membrane. At the same time, the siloxane bond has the flexibility of ether bond, and the silicon element increases the use of the membrane at low temperature, which further improves the low-temperature resistance of the membrane. From the results of Example 1-5, it can be seen that the change of the type of diisocyanate has little effect on the heat resistance of the membrane. However, the introduction of rigid structure of aromatic or alicyclic structure reduces the low-temperature performance of the membrane, and the membrane is prone to brittle fracture at low temperature, which affects the use. The long-chain flexible structure effectively improves the low-temperature resistance of the membrane. From the results of Example 3, Example 6-8, it can be seen that with the increase of the amount of diisocyanate, the high-temperature resistance and low-temperature resistance of the membrane gradually increase. However, excessive isocyanate will introduce branched structure into the polyurethane backbone, which reduces the low-temperature resistance of the membrane. From the results of Example 3, Example 9-11, it can be seen that with the increase of the amount of hydroxyl-terminated polydimethylsiloxane, the high-temperature resistance gradually increases, and the low-temperature resistance shows a trend of first increasing and then decreasing. From the results of Example 3, Example 12-13, it can be seen that with the increase of the molecular weight of hydroxyl-terminated polydimethylsiloxane, the heat resistance gradually increases, and the low-temperature resistance shows a trend of first increasing and then decreasing. With the increase of the molecular weight of the chain segment, the unreacted siloxane is enriched in the polyurethane material, which destroys the continuity of the macromolecular chain segment in the membrane and further reduces the low-temperature resistance. From the results in Table 2, it can be seen that by changing the type of diisocyanate, the amount of diisocyanate and hydroxyl-terminated polydimethylsiloxane, the low-temperature flexibility of the modified asphalt waterproofing membrane is -42℃, and the softening point is 153℃, which shows obvious improvement in high-temperature resistance and low-temperature resistance.

[0058] Example 15-24 The preparation method and parameters of Example 3 were used as reference, and the differences are shown in Table 3.

[0059] Comparative Example 2 The preparation method and parameter conditions are the same as those in Example 3, except that the modified polyurethane-modified asphalt is not added.

[0060] Comparative Example 3 The preparation method and parameter conditions are the same as those in Example 3, except that no epoxy resin is added to the modified polyurethane.

[0061] Example 25 Tensile Strength Test

[0062] The modified asphalt waterproofing membranes prepared in Examples 15-24 and Comparative Examples 3-4 were subjected to tensile performance tests. According to the standard GB18242-2008, the above waterproofing membranes were subjected to tensile strength and elongation at break tests. During the stretching process, no asphalt cracking or separation from the base occurred in the modified asphalt waterproofing membranes. The transverse tensile strength and longitudinal tensile strength test results are shown in Table 3. The transverse tensile strength and elongation at break results of Examples 15-18 are shown in Table 3. Figure 1 shown.

[0063] Table 3 Tensile performance test of Examples 15-24 and Comparative Examples 3-4

[0064]

[0065] The results in Table 3 show that the tensile strength of the waterproof membrane prepared by adding modified polyurethane modified asphalt in Comparative Example 3 is significantly lower than that of the polyurethane modified without epoxy in Comparative Example 4, indicating that the use of epoxy resin to modify the polyurethane and the use of maleic anhydride can increase the compatibility of the modified polyurethane with asphalt. At the same time, the polyurethane can form a three-dimensional interpenetrating network structure with the epoxy resin, wrapping the asphalt in the waterproof membrane. After curing with the curing agent in the composite base, the three-dimensional structure of the cured modified asphalt waterproof membrane is more stable, further improving the mechanical properties of the membrane. Figure 1, The results of Examples 15-18 show that with the increase of the epoxy resin epoxidation degree, the transverse tensile strength of the coiled material can reach 1315N / mm, and the longitudinal tensile strength can reach 1228N / mm, showing significantly improved tensile properties. With the increase of the epoxy resin epoxidation degree, a large number of hydrogen bonds can be formed between the soft and hard segments of the polyurethane. The increase in the crosslinking degree and hydrogen bond density of the epoxy resin and the polyurethane forms a fuzzy interface layer between the soft and hard segments of the polyurethane. The fuzzy interface layer serves as a transition layer between the soft segment and the hard segment, which can not only effectively separate the soft and hard segments, but also form a strong non-covalent bond attraction between the soft and hard segments, thereby improving the tensile properties and elongation at break of the coiled material; Implementation The results of Examples 18-21 show that with the increase in the amount of epoxy resin, the tensile strength of the roll shows a trend of gradually increasing and stabilizing, the cross-linking degree reaches saturation, and the modified asphalt and the base form a stable network structure under the action of polarity, thereby improving the tensile strength; the results of Examples 18 and 22-24 show that with the increase in the content of modified polyurethane, the tensile strength of the waterproof roll shows a trend of first increasing and then decreasing, the compatibility of excessive modified polyurethane with asphalt deteriorates, and some modified polyurethanes fail to be successfully grafted into the asphalt molecules. The generated urea groups will destroy the uniformity of the interpenetrating network to a certain extent, thereby reducing the mechanical properties of the roll; as shown in Table 3, Figure 1 The results show that by controlling the type of epoxy resin and the ratio of epoxy resin to polyurethane prepolymer and the amount of modified polyurethane, the modified asphalt waterproof membrane has a transverse tensile strength of 1315N / mm and a longitudinal tensile strength of 1228N / mm, showing significantly improved mechanical properties.

[0066] Examples 26-37 were prepared with reference to the preparation methods and parameter conditions of Example 18, with the differences shown in Table 4.

[0067] Comparative Example 5 The preparation method and parameter conditions are the same as those of Example 18, except that the modified glass fiber is not added.

[0068] Comparative Example 6 The preparation method and parameter conditions are the same as those of Example 18, except that unmodified glass fiber is added.

[0069] Example 38 Water resistance test

[0070] With reference to GB 18242-2008 “Elastomer-modified asphalt waterproof membrane”, the waterproof membranes prepared in Examples 26-37 and Comparative Examples 5-6 were subjected to a water-impermeability test at a test pressure of 0.3 MPa. The water resistance of the membranes was tested by measuring the water-impermeability maintenance time. The test results are shown in Table 4.

[0071] Table 4 Water resistance test of Examples 26-37 and Comparative Examples 5-6

[0072]

[0073] The results in Table 4 show that the modified asphalt waterproofing membranes prepared in Comparative Examples 5-6 have a significantly reduced water-impermeability due to the lack of pre-emulsion-modified glass fiber. The results in Examples 26-29 show that with the change of the functional monomer in the pre-emulsion, the water-impermeability of the membrane changes significantly. When using fluorine-containing functional monomers, fluorine atoms will migrate to the interface formed by the membrane and the air as the water evaporates during the emulsion film formation process, forming a dense protective film on the surface of the waterproofing membrane, thereby improving the water resistance of the membrane. When methacrylic acid is used as the functional monomer, the increase in polar groups on the surface of the membrane increases the interaction between water molecules and the membrane, thereby reducing the water resistance. The results in Examples 26 and 30-32 show that with the increase in the amount of functional monomer used, the fluorine atom content increases, forming a dense film structure on the surface of the membrane, reducing the water resistance. The influence of the substrate on the roll material gradually extends the impermeability time of the waterproof roll material; the results of Example 26 and Examples 33-34 show that the use of glass fiber reinforced polyester base increases the compatibility with the modified glass fiber, and the polar groups in the modified glass fiber and the base are cross-linked, so that the non-polar fluorine-containing functional monomers migrate to the interface formed by the roll material and the air, further increasing the water resistance of the roll material; the results of Examples 33 and Examples 35-37 show that with the increase in the amount of composite base, the impermeability time of the roll material gradually extends and tends to be unchanged. The amount of composite base is low, and the fluorine-containing protective film formed by the functional monomer migrates to the surface of the roll material. The content is less, and a dense membrane structure cannot be formed on the surface of the modified asphalt and the air. Water molecules enter the interior of the roll material through the polyurethane and epoxy resin system of the modified asphalt layer, reducing the service life of the waterproof roll material. The results in Table 4 show that by using perfluorooctyl ethyl acrylate as the functional monomer to prepare the pre-emulsion, controlling the type of base and the amount of composite base, the modified asphalt waterproof membrane prepared can achieve 5.5h of impermeability under 0.3MPa conditions, showing significantly improved water resistance.

[0074] Examples 39-50 The preparation methods and parameter conditions are similar to those of Example 33, with the differences shown in Table 5.

[0075] Comparative Example 7 The preparation method and parameter conditions are the same as those of Example 33, except that maleic anhydride is not added.

[0076] Comparative Example 8 The preparation method and parameter conditions are the same as those in Example 33, except that the pre-emulsion-modified glass fiber is not added.

[0077] Example 51 Peeling Performance Test

[0078] The modified asphalt waterproof membranes obtained in Examples 39-50 and Comparative Examples 7-8 were subjected to peeling performance tests. Peeling strength tests were performed on the above waterproof membranes according to GB18242-2008. The test results are shown in Table 5.

[0079] Table 5 Peeling performance test of Examples 39-50 and Comparative Examples 7-8

[0080]

[0081] The results in Table 5 show that the peel strength of the waterproof roll prepared by the modified asphalt without adding maleic anhydride in Comparative Example 7 is significantly lower than that of Examples 39-50. Due to the addition of maleic anhydride, the compatibility of the modified asphalt and the modified polyurethane is increased, the binding force between the components in the modified asphalt is improved, and the agglomeration of graphene particles caused by temperature changes during the drying process is avoided. At the same time, the addition of maleic anhydride improves the compatibility between latex and modified polyurethane, thereby improving the stability of the modified asphalt and avoiding the pre-impregnation and roller pressing of the composite tire base. The drying process causes unevenness between the layers of the coiled material, reducing the overall performance of the coiled material; in Comparative Example 8, no pre-emulsion is added, which further improves the peel strength of the coiled material. The addition of acrylate pre-emulsion can combine with the polyurethane and epoxy resin in the modified asphalt, and a curing reaction occurs during the drying process, cross-linking to form a stable network structure, further improving the peel strength; the results of Examples 39-42 show that with the increase in the amount of maleic anhydride used, the peel strength of the waterproof coiled material gradually increases. However, excessive maleic anhydride will reduce the water resistance effect of the fluorine monomer in the pre-emulsion, reducing the performance of the coiled material. The results of Examples 39 and 43-45 show that with the increase of the modified asphalt content, the peel strength of the coiled material shows a trend of gradual increase. When the amount of modified asphalt reaches 300 parts, the increase in peel strength gradually slows down, indicating that the crosslinking of the modified asphalt and the composite base has reached a stable state with little change. The results of Examples 39 and 46-47 show that with the increase of the amount of composite base, the peel strength of the coiled material shows a trend of first increasing and then decreasing. Due to the excessive amount of composite base, the presence of a large amount of non-polar fluorine groups reduces the crosslinking of the modified asphalt and the composite base. The peel strength of the modified asphalt waterproof membrane is reduced by cross-linking and curing with the composite base. The results of Examples 39 and 48-50 show that with the increase of the drying temperature, the peel strength gradually increases and tends to be constant. The increase in temperature is conducive to the cross-linking and curing of the acrylic pre-emulsion and the polyurethane-epoxy resin system in the modified asphalt to form a stable network structure. The results in Table 5 show that by changing the amount of modified asphalt and the composite base and controlling the drying and curing temperature, the peel strength of the modified asphalt waterproof membrane obtained is 3.28 N / mm, showing significantly improved adhesion.

[0082] Examples 52-61 were prepared according to the method and parameters of Example 39, with the differences shown in Table 6.

[0083] Comparative Example 9 The preparation method and parameter conditions are the same as those of Example 39, except that no antioxidant was added and 35 parts of epoxy resin were added.

[0084] Comparative Example 10 The preparation method and parameter conditions are the same as those of Example 39, except that titanium dioxide is not added.

[0085] Example 62 Aging resistance test

[0086] Samples of the modified asphalt waterproof membranes prepared in Examples 52-61 and Comparative Examples 9-10, measuring 180 x 25 mm, were placed in a UV aging chamber and subjected to accelerated UV aging testing using the low-temperature flexibility obtained in Example 14 and the elongation at break measured in Example 25. The test temperature was 80°C, the light source was an 800W high-pressure mercury lamp, the distance between the sample and the lamp was 20 mm, and the irradiation time was 800 hours. The tensile strength of the composites before and after irradiation was measured, and the strength retention was calculated. The low-temperature flexibility was also recorded. The test results are shown in Table 6.

[0087] Table 6 Aging resistance test of Examples 52-61 and Comparative Examples 9-10

[0088]

[0089] From the results of Table 6, it can be seen that the anti-aging performance of the modified asphalt waterproofing membrane prepared in Example 9 without adding an antioxidant as a capping agent for the polyurethane is significantly reduced relative to Examples 52-61; the anti-aging performance of the waterproofing membrane prepared in Comparative Example 10 without adding titanium dioxide is significantly improved relative to Comparative Example 9, but the strength retention rate is only 80.2%, still showing poor anti-aging performance, and the addition of titanium dioxide provides UV shielding performance for the waterproofing membrane, which can reduce the damage of UV light to the membrane; from the results of Examples 52-55, it can be seen that as the amount of antioxidant increases, the anti-aging performance of the waterproofing membrane shows a trend of first increasing and then decreasing, the addition of the antioxidant introduces a UV shielding agent into the main chain structure of the modified asphalt, reducing the influence of free radical molecules on the intermolecular forces of the modified asphalt, thereby reducing the anti-aging performance of the waterproofing membrane, but the addition of an excessive amount of antioxidant introduces a large number of non-polar groups into the membrane, which cannot form a stable cross-linked structure during curing, and under the long-term action of UV light, the polar groups inside the material are oxidized by UV light, resulting in a decrease in the strength retention rate; from the results of Examples 52, 56-58, it can be seen that as the amount of modified polyurethane increases, the anti-aging performance of the waterproofing membrane gradually improves, but the addition of an excessive amount of modified polyurethane leads to poor compatibility with the asphalt, and part of the modified polyurethane fails to be successfully grafted to the asphalt molecules, and the generated urea groups will destroy the uniformity of the interpenetrating network to some extent, reducing the mechanical properties of the membrane; from the results of Examples 52, 59-61, it can be seen that as the amount of titanium dioxide increases, the anti-aging performance of the waterproofing membrane gradually improves, showing a gradual increase in the strength retention rate and tending to be constant, but the addition of an excessive amount of titanium dioxide particles increases the possibility of agglomeration of titanium dioxide particles with mineral particles, further affecting the overall performance of the membrane during use; from the results of Table 6, it can be seen that the use of modified polyurethane modified asphalt capped with an antioxidant and the addition of titanium dioxide for synergistic use results in a modified asphalt waterproofing membrane with a strength retention rate of 98.6% after 800 h of irradiation at 80°C and a low-temperature flexibility of -35°C, showing significantly improved anti-aging performance.

[0090] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a modified asphalt waterproof membrane, characterized in that: The preparation method comprises the following steps: The modified glass fiber is mixed with the front and back sides of the base and rolled to obtain a composite base; the composite base is pre-impregnated with modified asphalt to obtain a pre-impregnated base; the modified asphalt is coated on the pre-impregnated base, and the roll is dried to obtain a roll material; the surface of the roll material is coated with a polypropylene film, mineral particles and titanium dioxide are added to the outermost layer in sequence, and the roll is cooled and formed to obtain the modified asphalt waterproof membrane; The modified asphalt is prepared by stirring and heating 90# asphalt, adding modified polyurethane and isoprene latex, stirring and adding graphene and maleic anhydride, and stirring and reacting; The modified polyurethane is prepared by polycondensation and chain extension of diisocyanate, terminal hydroxyl polydimethylsiloxane and butanediol, end-capping with an antioxidant, and modification with an epoxy resin; The modified glass fiber is obtained by stirring and reacting acrylonitrile, vinyl acetate, hydroxyethyl acrylate and functional monomers on a glass fiber precursor; The functional monomer is selected from one of perfluorooctyl ethyl acrylate, hexafluorobutyl methacrylate, methacrylic acid, and 2-(perfluorodecyl)ethyl methacrylate; The glass fiber is subjected to the steps of dewaxing and alkali treatment to obtain the glass fiber precursor; ammonium persulfate and NaHCO3 are added to a four-necked flask, added to deionized water, stirred and dissolved, and stirred for 10 minutes at room temperature to obtain a pre-reaction liquid; the pre-reaction liquid is heated, the glass fiber precursor is added, and stirred to obtain a stirred liquid; a pre-emulsion is dropped into the stirred liquid, and the temperature is increased for reaction to obtain a reaction liquid; the reaction liquid is cooled, washed with deionized water, extracted with ethanol, and vacuum dried to obtain the modified glass fiber.

2. The method for preparing a modified asphalt waterproof membrane according to claim 1, characterized in that: The tire base is selected from one of a polyester tire base, a polyamide tire base, and a glass fiber reinforced polyester tire base.

3. The method for preparing a modified asphalt waterproof membrane according to claim 1, characterized in that: The preparation of the modified polyurethane comprises the following steps: Adding 2-(2-chlorophenyl)-4,6-diphenyl-1,3,5-triazine, 4-hydroxyphenylboric acid, tetrakistriphenylphosphine palladium, and cesium carbonate to 1,4-dioxane, and reacting at 100° C. for 6 hours to obtain a reaction system; cooling the reaction system, adding water and ethyl acetate to dilute, extracting and separating, distilling under reduced pressure, and drying to obtain the antioxidant; 60-90 parts of the diisocyanate and 30-60 parts of the hydroxy-terminated polydimethylsiloxane were dried in a vacuum drying oven at 80° C. for 2 hours to obtain a dry raw material; the dry raw material was added to a four-necked flask and dissolved in DMF to obtain a solution system; the solution system was protected by nitrogen, heated to 50° C., and dibutyltin dilaurate was added and reacted for 3 hours to obtain a reaction system; 10 parts of butanediol was added to the reaction system and chain extended for 2 hours to obtain a polyurethane prepolymer. The polyurethane prepolymer is cooled to 40° C., 8-18 parts of the antioxidant is added, and the mixture is reacted at 60° C. for 2 hours to obtain an intermediate; the intermediate is cooled to room temperature, triethylamine is added to neutralize the reaction system, and the mixture is reacted for 30 minutes to obtain a neutralization system; the epoxy resin and dibutyltin dilaurate are added to the neutralization system, and the mixture is reacted at 70° C. for 3 hours to obtain a reactant; the reactant is cooled and vacuum degassing is performed to obtain the modified polyurethane.

4. The method for preparing a modified asphalt waterproof membrane according to claim 1, characterized in that: The preparation of the modified asphalt comprises the following steps: The 90# asphalt is added to a reaction tank preheated at 150°C and melted, and the mixture is stirred and heated to obtain a mixture; 20-50 parts of the modified polyurethane and 10 parts of the isoprene latex are added to the mixture, and the mixture is stirred for 2 hours, and then 5 parts of the graphene are added, the temperature is raised to 200°C, and the mixture is stirred at 3500 rpm for 30 minutes to obtain a mixed material; 3-8 parts of maleic anhydride are added to the mixture, and the mixture is stirred to react to obtain modified asphalt.

5. The method for preparing a modified asphalt waterproof membrane according to claim 3, characterized in that: The diisocyanate is selected from one of toluene diisocyanate, lysine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and terephthalylidene diisocyanate; and the average molecular weight of the hydroxyl-terminated polydimethylsiloxane is 1600-2800.

6. The method for preparing a modified asphalt waterproof membrane according to claim 3, characterized in that: The epoxy resin is selected from one of E42, E44, E51, and E52; the ratio of the epoxy resin to the polyurethane prepolymer is 1:3-10.

7. The method for preparing a modified asphalt waterproof membrane according to claim 1, characterized in that: The preparation of the pre-emulsion comprises the following steps: Sodium lauryl sulfate was added to a four-necked flask, and then added to deionized water and stirred for 15 minutes to prepare a mixed emulsion; 50 parts of acrylonitrile, 20 parts of vinyl acetate, 10 parts of hydroxyethyl acrylate, and 3-10 parts of functional monomers were added to the mixed emulsion, and stirred for pre-emulsification for 30 minutes to prepare the pre-emulsion.

8. A modified asphalt waterproof membrane, characterized by: The modified asphalt waterproofing membrane comprises 250-400 parts of modified asphalt, 30-60 parts of composite base, 30 parts of mineral particles, and 3-10 parts of titanium dioxide; The modified asphalt waterproof membrane is prepared by the method according to any one of claims 1 to 7.

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