A toughening agent for high-toughness epoxy used in road and bridge, preparation method thereof and usage method thereof

Abstract

The present invention provides a toughening agent for high-toughness epoxy used in road and bridge, a preparation method thereof and a usage method thereof, which includes a mono-hydroxy epoxy-capped polyurethane prepolymer and a phenol-capped polyurethane prepolymer with a mass ratio of 100:50 to 200. The coexistence of the mono-hydroxy epoxy-capped polyurethane prepolymer and the phenol-capped polyurethane prepolymer ensures that an interpenetrating network structure is formed during the curing process of the high-toughness epoxy for road and bridge. The cured product has properties such as high-temperature rutting resistance, medium-temperature fatigue resistance, and low-temperature crack resistance, perfectly solving the problems of insufficient toughness and poor fatigue resistance of epoxy mixtures. The ingenious temporary closure of the terminal isocyanate group polyurethane prepolymer by phenolic hydroxyl groups solves technical defects such as too high activity and poor storage stability of the terminal isocyanate group polyurethane prepolymer, meeting the technical requirements of workability for road and bridge paving.

Description

Technical Field

[0001] The present invention relates to the technical field of road and bridge materials, and particularly to a toughening agent for high-toughness epoxy for road and bridge, a preparation method thereof, and a usage method thereof. Background Art

[0002] Epoxy resin has excellent bonding properties, good dimensional stability, outstanding anti-aging performance, etc., and can be widely used in the field of civil engineering. However, unmodified epoxy resin without toughening and softening has high stiffness and modulus, and the prepared epoxy mixture has sufficient strength but insufficient deformation ability, unable to meet the requirements of road and bridge paving for the deformation ability of the binder. Introducing asphalt with excellent deformation ability into epoxy resin, the prepared epoxy asphalt meets the requirements of road and bridge paving for the strength and deformation performance of the binder. However, the long-term phase stability of epoxy asphalt is insufficient, and the asphalt dispersed phase will gradually migrate and precipitate from the epoxy continuous phase, resulting in the loss of the mechanical properties of the epoxy asphalt mixture.

[0003] In order to meet the urgent needs of road and bridge paving for high-performance modified epoxy binders, scholars at home and abroad have gradually explored using 100% epoxy resin as the binder for road and bridge paving and performing softening and toughening modifications on it to simultaneously meet the performance requirements of strength and deformation. The existing polyurethane-modified epoxy technology mostly introduces 5% - 30% of terminal isocyanate group polyurethane prepolymer into the epoxy resin system to form an EP-PU interpenetrating network. This technology has limited toughening effect on epoxy resin and still cannot meet the deformation requirements of paving materials in the wide frequency and wide temperature range under frequent vehicle impact loads. Therefore, researching toughening agents suitable for road and bridge paving that can improve the toughness and fatigue resistance of epoxy mixtures is of great significance for preparing high-performance modified epoxy binders for road and bridge paving with high-temperature rutting resistance, medium-temperature fatigue resistance, and low-temperature cracking resistance.

[0004] The information disclosed in this background art section is only intended to deepen the understanding of the overall background art of the present invention, and should not be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0005] The first object of the present invention is to provide a toughening agent for high-toughness epoxy for road and bridge. Mixing it with components such as liquid epoxy, active diluent, curing agent, etc. to obtain a high-toughness epoxy binder for road and bridge, and then directly putting it into the mixing tank of an asphalt mixing plant to prepare a high-toughness epoxy mixture for road and bridge with high-temperature rutting resistance, medium-temperature fatigue resistance, and low-temperature cracking resistance, so as to solve the problems of insufficient toughness and poor fatigue resistance of epoxy mixtures in road and bridge paving.

[0006] The above technical object of the present invention is achieved through the following technical solutions:

[0007] A toughening agent for high-toughness epoxy used in road and bridge engineering, comprising a mono-hydroxy epoxy-capped polyurethane prepolymer and a phenol-capped polyurethane prepolymer with a mass ratio of 100:50 to 200;

[0008] The phenol-capped polyurethane prepolymer can be deblocked under medium temperature (40 - 80 °C) and the synergistic action of an amine curing agent to form phenolic compounds and a terminal isocyanate group-containing polyurethane prepolymer.

[0009] The principle of the amine curing agent promoting the deblocking of the phenol-capped polyurethane prepolymer is as follows

[0010]

[0011] Furthermore, the mono-hydroxy epoxy-capped polyurethane prepolymer is prepared by capping a terminal isocyanate group-containing polyurethane prepolymer with a mono-hydroxy epoxy compound under the action of catalyst I.

[0012] Furthermore, the phenol-capped polyurethane prepolymer is prepared by capping a terminal isocyanate group-containing polyurethane prepolymer with a phenolic compound under the action of catalyst II.

[0013] Furthermore, the terminal isocyanate group-containing polyurethane prepolymer is prepared by reacting a polyisocyanate and a polyol.

[0014] Furthermore, catalyst I is one or more of dibutyltin dilaurate, stannous octoate, dibutyltin dioleate, and dibutyltin dimaleate. Since the mono-hydroxy epoxy compound has a relatively high hydroxyl value and a group with a steric hindrance effect in its molecular structure, to a certain extent, the reaction activity between the hydroxyl group in the mono-hydroxy epoxy compound and the polyisocyanate is not high. To achieve the capping of the terminal isocyanate group-containing polyurethane prepolymer with the mono-hydroxy epoxy compound, an organotin catalyst is introduced to reduce the reaction difficulty between the hydroxyl group in the mono-hydroxy epoxy compound and the isocyanate group in the terminal isocyanate group-containing polyurethane prepolymer.

[0015] Furthermore, the mono-hydroxy epoxy compound is one or more of butanediol monoglycidyl ether, hexanediol monoglycidyl ether, glycerol diglycidyl ether, pentaerythritol triglycidyl ether, trimethylolpropane diglycidyl ether, bisphenol A diglycidyl ether, and bisphenol F diglycidyl ether. To achieve the epoxy capping of the terminal isocyanate group-containing polyurethane prepolymer, the present invention uses a compound having both a hydroxyl group and an epoxy group, and grafts the mono-hydroxy epoxy compound onto the molecular structure of the polyurethane prepolymer by the reaction between the hydroxyl group and the isocyanate group in the terminal isocyanate group-containing polyurethane prepolymer, thereby realizing the terminal epoxy functionalization of the polyurethane prepolymer.

[0016] Further, the catalyst II is one or more of N-N'-dimethyldodecylamine, N-N'-dimethylcyclohexylamine, N-N-N'-N'-tetramethylethylenediamine, and N-N-N'-N'-tetramethyl-1,6-hexanediamine. The reaction activity between the phenolic hydroxyl group in the phenolic compound and the isocyanate group in the terminal isocyanate group polyurethane prepolymer is not high, and the terminal isocyanate group polyurethane prepolymer has a tendency of self-polymerization under heating conditions. In order to promote the reaction between the phenolic hydroxyl group and the terminal isocyanate group polyurethane prepolymer, tertiary amine catalysts are screened to selectively catalyze the reaction between the phenolic hydroxyl group and the isocyanate group and inhibit the self-polymerization reaction between the isocyanate groups.

[0017] Further, the phenolic compound is a substituted phenol, and its molecular structure is shown in the following formula.

[0018]

[0019] In the formula, X is H, Cl, NO2, or COOCH3; Y is H, Cl, NO2, or COOCH3. Compared with the deblocking temperature of phenol being higher when the alkyl electron-donating group substitutes phenol, the deblocking temperature in the present invention is lower than that of phenol, which can ensure the formation of the three-network synchronous interpenetrating structure and improve the toughness of the epoxy resin.

[0020] In view of the current insufficient toughness of epoxy resin and the problem that the toughness is still poor in the two-network interpenetrating structure, the present invention introduces a three-network synchronous interpenetrating structure. However, when introducing the three networks, the reaction activity of the terminal isocyanate group polyurethane prepolymer and the amine curing agent is much greater than that of epoxy resin, and it is easy to rapidly gel at room temperature, which cannot meet the requirements of workability for the epoxy binder in road and bridge paving. Moreover, the isocyanate (NCO) group in the terminal isocyanate group polyurethane prepolymer has high activity and is easy to cross-link with water vapor in the air, resulting in poor long-term storage stability and unable to meet the actual engineering requirements. Although phenol capping can indeed solve the problems of reactivity and storage stability, since its deblocking temperature is as high as above 130 °C and the deblocking conditions cannot be achieved during the construction process, a three-network synchronous interpenetrating structure cannot be formed, and the problem of insufficient toughness still cannot be solved. The present invention preferably uses ortho- and para-substituted phenols as phenolic compounds to cap the terminal isocyanate group polyurethane prepolymer, and further preferably uses -Cl, -NO2, -COOCH3 as ortho- and para-substituents, and further reduces the deblocking temperature of the phenol-capped polyurethane prepolymer to 60-80 °C by using the inductive effect and steric hindrance effect of the above substituents. The presence of the amine curing agent can further reduce the deblocking temperature to 40-60 °C, and the terminal isocyanate group polyurethane prepolymer is gradually released to participate in the formation of the three-synchronous interpenetrating network structure of the modified epoxy binder, and the released phenolic compounds have a certain promoting effect on the reaction between the epoxy group and the amine curing agent. Therefore, the present application preferably uses disubstituted phenol for temporary capping, which can not only solve the problem of poor epoxy toughness, but also cleverly solve the problems of storage stability and reactivity.

[0021] The second object of the present invention is to provide a preparation method of a toughening agent for high-toughness epoxy in road and bridge, so as to solve the problem of insufficient toughness of epoxy.

[0022] The above technical object of the present invention is achieved by the following technical solutions:

[0023] A preparation method of a toughening agent for high-toughness epoxy in road and bridge includes the following operation steps:

[0024] S1. React an excessive amount of polyisocyanate with a polyol in proportion to obtain a terminal isocyanate group polyurethane prepolymer;

[0025] S2. Add a monohydroxy epoxy compound and a catalyst I to the product of S1 in proportion to obtain a monohydroxy epoxy-capped polyurethane prepolymer;

[0026] S3. Add a phenolic compound and a catalyst II to the product of S1 in proportion to obtain a phenol-capped polyurethane prepolymer;

[0027] S4. Mix the monohydroxy epoxy-capped polyurethane prepolymer in S2 and the phenol-capped polyurethane prepolymer in S3 evenly to obtain a toughening agent for high-toughness epoxy in road and bridge.

[0028] Preferably, a preparation method of an epoxy asphalt additive for road and bridge paving includes the following operation steps:

[0029] S1. Dehydrate the polyol at 105°C under N2 conditions. Gradually add the polyisocyanate to the dehydrated polyol at a ratio of n(NCO) / n(OH) of 2.05 / 1, and react at 60 - 80°C under N2 conditions until the NCO content in the synthesis product reaches the theoretical value to obtain an isocyanate-terminated polyurethane prepolymer.

[0030] S2. Add the monohydroxy epoxide to the isocyanate-terminated polyurethane prepolymer obtained in S1 at a ratio of n(NCO) / n(OH) of 1 / 1.05, and add 0.1% - 0.5% of catalyst I, then react at 60 - 80°C under N2 conditions until the residual NCO content in the synthesis product is ≤0.1% to obtain a monohydroxy epoxy-capped polyurethane prepolymer.

[0031] S3. Add the phenolic compound to the synthesis product obtained in S1 at a ratio of n(NCO) / n(OH) of 1 / 1.05, and add 0.1% - 0.5% of catalyst II, then react at 40 - 80°C under N2 conditions until the residual NCO content in the synthesis product is ≤0.1% to obtain a phenol-capped polyurethane prepolymer.

[0032] S4. Mix the monohydroxy epoxy-capped polyurethane prepolymer and the phenol-capped polyurethane prepolymer evenly at a mass ratio of 100:50 - 200 to obtain a toughening agent for high-toughness epoxy for road and bridge.

[0033] The third object of the present invention is to provide a usage method of a toughening agent for high-toughness epoxy for road and bridge, which has the same technical effect.

[0034] The above technical object of the present invention is achieved by the following technical solutions:

[0035] A usage method of a toughening agent for high-toughness epoxy for road and bridge includes the following operation steps:

[0036] P1. Stir and mix the liquid epoxy resin, the toughening agent for high-toughness epoxy for road and bridge, the reactive diluent, the coupling agent, etc. evenly according to the ratio to obtain the component A of high-toughness epoxy for road and bridge.

[0037] P2. Stir and mix the polyetheramine curing agent and the low-molecular polyamide curing agent evenly according to the ratio to obtain the component B of high-toughness epoxy for road and bridge.

[0038] P3. Stir and mix the component A of high-toughness epoxy for road and bridge in P1 and the component B of high-toughness epoxy for road and bridge in P2 evenly according to the ratio to obtain a high-toughness epoxy binder for road and bridge.

[0039] P4. Mix the road and bridge high-toughness epoxy binder and graded stone materials in P3 proportionally and evenly to obtain the road and bridge high-toughness epoxy mixture.

[0040] Furthermore, the specific usage method of a toughening agent for road and bridge high-toughness epoxy is as follows:

[0041] P1. Weigh components such as liquid epoxy resin, toughening agent for road and bridge high-toughness epoxy, active diluent, and coupling agent in a ratio of 10 - 20:70 - 80:10:1. Then gradually heat up to 40 - 60°C and stir and mix for 1 - 3 hours to obtain the component A of road and bridge high-toughness epoxy.

[0042] P2. Weigh components such as polyetheramine curing agent and low-molecular polyamide curing agent in a ratio of 1 - 2:1 - 2. Then gradually heat up to 40 - 60°C and stir and mix for 1 - 3 hours to obtain the component B of road and bridge high-toughness epoxy.

[0043] P3. Preheat the component A of road and bridge high-toughness epoxy in P1 and the component B of road and bridge high-toughness epoxy in P2 to 30 - 40°C respectively. Then weigh the component A and component B in a mass ratio of 2 - 4:1 and stir and mix for 1 - 3 minutes to obtain the road and bridge high-toughness epoxy binder.

[0044] P4. Put the road and bridge high-toughness epoxy binder in P3 into the mixing tank proportionally and stir and mix evenly with graded stone materials (Zhenjiang Maodi basalt aggregate, 5 - 10mm:3 - 5mm:1 - 3mm:0.075 - 1mm:mineral powder = 25:21.5:22:23:8.5) to obtain the road and bridge high-toughness epoxy mixture. The mass ratio between the graded stone materials and the road and bridge high-toughness epoxy binder is 100:6.0 - 8.0.

[0045] Beneficial effects

[0046] By means of the above technical solution, the present invention has at least the following advantages:

[0047] (1) The present invention respectively forms a synchronous interpenetrating network containing a small-molecule rigid epoxy network, a large-molecule flexible epoxy network, and a large-molecule flexible polyurethane network based on the crosslinking and curing reactions between liquid epoxy, monohydroxy epoxy-capped polyurethane prepolymer, and phenol-capped polyurethane prepolymer and amine curing agents, which can meet the usage requirements of road and bridge paving for the strength, toughness, deformation ability, etc. of the modified epoxy binder. The core of the present invention is to adjust the mechanical properties of the modified epoxy resin binder by adjusting the ratio between the monohydroxy epoxy-capped polyurethane prepolymer and the phenol-capped polyurethane prepolymer in the toughening agent, thereby realizing the adjustment of the synchronous interpenetrating network structure.

[0048] (2) In the present invention, a mono-hydroxy epoxide and a phenolic compound are respectively used to cap the terminal isocyanate prepolymer. The residual NCO (isocyanate) content in the toughener thus prepared is less than 0.1%, avoiding failure caused by gelation due to the reaction of residual NCO with water vapor, etc. during long-term storage, and meeting the long-term storage stability requirements of modified epoxy binder for road and bridge paving.

[0049] (3) In the present invention, the phenol-capped polyurethane prepolymer can be uncapped at 60 - 80 °C to release the terminal isocyanate polyurethane prepolymer, which gradually participates in the formation of the synchronous interpenetrating network structure of the modified epoxy binder. The presence of an amine curing agent can further lower the uncapping temperature to 40 - 60 °C, and the released phenolic compound has a certain promoting effect on the reaction between the epoxy group and the amine curing agent. The temporary closure of the terminal isocyanate polyurethane prepolymer by phenolic hydroxyl groups ingeniously solves the problem of rapid gelation caused by the fact that the reaction activity of the terminal isocyanate polyurethane prepolymer (with the amine curing agent) is much greater than that of the mono-hydroxy epoxy-capped polyurethane prepolymer. The modified epoxy binder thus prepared has a longer pot life and is more convenient for construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for description in the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0051] Figure 1 It is a schematic diagram of the high-toughness epoxy interpenetrating network structure for road and bridge;

[0052] Figure 2 It is a preparation flow chart of the high-toughness epoxy binder for road and bridge in the present invention.

[0053] Reference numerals: 1, macromolecular flexible epoxy network; 2, macromolecular flexible polyurethane network; 3, small-molecule rigid epoxy network. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments.

[0055] Sources of raw materials used in the embodiments:

[0056] Polyisocyanate: TDI-80, MDI-100, Wanhua Chemical Group Co., Ltd.

[0057] Polyols: PPG1000, PPG2000, PPG4000, Nanjing Jinqi Chemical Co., Ltd.

[0058] Monohydroxy epoxy compounds: butanediol monoglycidyl ether, hexanediol monoglycidyl ether, glycerol diglycidyl ether, pentaerythritol triglycidyl ether, trimethylolpropane diglycidyl ether, bisphenol A glycidyl ether, bisphenol F glycidyl ether, Sigma-Aldrich (Shanghai) Trading Co., Ltd.

[0059] Phenolic compounds: phenol, 2,4-dichlorophenol, 3-chloro-4-hydroxybenzoic acid methyl ester, 2-chloro-4-nitrophenol, Sigma-Aldrich (Shanghai) Trading Co., Ltd.

[0060] Catalyst I: dibutyltin dilaurate, stannous octoate, dibutyltin dioleate, dibutyltin dimaleate, Xindian Chemical Materials (Shanghai) Co., Ltd.

[0061] Catalyst II: N-N'-dimethyldodecylamine, N-N'-dimethylaminocyclohexylamine, NN-N'-N'-tetramethylethylenediamine, NN-N'-N'-tetramethyl-1,6-hexanediamine, Sigma-Aldrich (Shanghai) Trading Co., Ltd.

[0062] Liquid epoxy: NPEL-128 (EEW=184~190), Nan Ya Epoxy Resin (Kunshan) Co., Ltd.

[0063] Active diluent: XY748, XY622, Anhui Xinyuan Technology Co., Ltd.

[0064] Coupling agent: KH560, Nanjing Shuguang Silane Chemical Co., Ltd.

[0065] Polyetheramine: D230, D400, Huntsman Company, USA.

[0066] Low molecular weight polyamide: Versamid 115, Versamid 140, Huntsman Company, USA.

[0067] Example 1

[0068] <Preparation of toughening agent for high-toughness epoxy for road and bridge>

[0069] S1. PPG1000 was dehydrated at 105°C and N2 for 2 hours, and then TDI-80 was evenly and gradually added dropwise within 2 hours according to n(NCO) / n(OH)=2.05 / 1, and then the reaction was continued at 70°C and N2 until the NCO content in the synthesized product reached the theoretical value, thereby obtaining a terminal isocyanate polyurethane prepolymer;

[0070] S2. According to n(NCO) / n(OH) = 1 / 1.05, bisphenol A glycidyl ether was added to the terminal isocyanate group polyurethane prepolymer, and 0.5 wt% of dibutyltin dilaurate was added. Then, the reaction was carried out under the conditions of 70 °C and N2 until the residual NCO content in the synthetic product was ≤ 0.1%, and a mono-hydroxy epoxy-capped polyurethane prepolymer was prepared.

[0071] S3. According to n(NCO) / n(OH) = 1 / 1.05, 2,4-dichlorophenol was added to the terminal isocyanate group polyurethane prepolymer, and 0.1 wt% of N,N'-dimethyl dodecylamine was added. Then, the reaction was continued under the conditions of 80 °C and N2 until the residual NCO content in the synthetic product was ≤ 0.1%, and a phenol-capped polyurethane prepolymer was prepared.

[0072] S4. The mono-hydroxy epoxy-capped polyurethane prepolymer and the phenol-capped polyurethane prepolymer were mixed evenly according to the mass ratio of 100:100, and the toughening agent T1 for high-toughness epoxy for road and bridge was obtained.

[0073] <Preparation of high-toughness epoxy binder for road and bridge>

[0074] P1. The above raw materials were weighed successively according to the ratio of liquid epoxy 128:toughening agent T1:active diluent 748:coupling agent KH560 = 10:80:10:1, and after stirring and mixing at 60 °C for 1 h, the high-toughness epoxy component A for road and bridge was prepared.

[0075] P2. The above raw materials were weighed successively according to the ratio of polyetheramine curing agent D400:low-molecular polyamide curing agent Versamid 115 = 1:1, and after stirring and mixing at 40 °C for 1 h, the high-toughness epoxy component B for road and bridge was prepared.

[0076] P3. The high-toughness epoxy component A and component B for road and bridge were weighed according to the mass ratio of 3:1, and after stirring and mixing at room temperature for 2 min, the high-toughness epoxy binder B1 for road and bridge was prepared. After curing at RT / 7d, relevant performance tests were carried out, and the relevant performance is shown in Table 1.

[0077] <Preparation of high-toughness epoxy mixture for road and bridge>

[0078] P4. The above-prepared high-toughness epoxy binder B1 for road and bridge and graded stone materials (Zhenjiang Maodi basalt aggregate, 5 - 10 mm:3 - 5 mm:1 - 3 mm:0.075 - 1 mm:mineral powder = 25:21.5:22:23:8.5) were put into a mixing tank according to the mass ratio of 7.0:100, and after stirring and mixing evenly, the high-toughness epoxy mixture M1 for road and bridge was prepared. After curing at RT / 7d, relevant performance tests were carried out, and the relevant performance is shown in Table 1.

[0079] Table 1. Performance test data in Example 1

[0080]

[0081] Note: The optimum asphalt-aggregate ratio of a-epoxy asphalt mixture is 6.5 wt%; the optimum asphalt-aggregate ratio of b-road and bridge high-toughness epoxy mixture is 7.5 wt%; c-BIV is epoxy asphalt provided by ChemCo System of the United States, A:B = 100:585; d-TAF is epoxy asphalt provided by Daiyu Construction Co., Ltd. of Japan, A:B:70# asphalt = 56:44:100.

[0082] From the above data, it can be seen that compared with the epoxy asphalt binder, the road and bridge epoxy binder prepared in this application has higher tensile strength at 23°C and a higher temperature range of ΔTTanδ>0.3, while the elongation at break at 23°C is smaller, indicating that the three-network synchronous interpenetrating structure prepared in this application has more excellent strength and deformation ability. The prepared mixture has a higher ultimate flexural tensile strain of the small beam at -10°C and a greater four-point bending fatigue life at 15°C, 10 Hz, and 800 με, which can meet the use requirements of the key paving materials for road and bridge paving.

[0083] Example 2

[0084] <Toughening agent for preparing road and bridge high-toughness epoxy>

[0085] S1. Dehydrate PPG2000 at 105°C under N2 conditions for 2 h, and then gradually and uniformly drop TDI-80 within 2 h according to n(NCO) / n(OH) = 2.05 / 1, and then continue to react at 80°C under N2 conditions until the NCO content in the synthesis product reaches the theoretical value to obtain a terminal isocyanate group polyurethane prepolymer;

[0086] S2. According to n(NCO) / n(OH) = 1 / 1.05, add butanediol monoglycidyl ether to the terminal isocyanate group polyurethane prepolymer, and add 0.1 wt% of stannous octoate, and then react at 60°C under N2 conditions until the residual NCO content in the synthesis product ≤ 0.1% to obtain a mono-hydroxy epoxy-capped polyurethane prepolymer;

[0087] S3. According to n(NCO) / n(OH) = 1 / 1.05, add methyl 3-chloro-4-hydroxybenzoate to the terminal isocyanate group polyurethane prepolymer, and add 0.5 wt% of N-N'-dimethylaminocyclohexylamine, and then continue to react at 40°C under N2 conditions until the residual NCO content in the synthesis product ≤ 0.1% to obtain a phenol-capped polyurethane prepolymer;

[0088] S4. Mix the mono-hydroxy epoxy-capped polyurethane prepolymer and the phenol-capped polyurethane prepolymer evenly according to a mass ratio of 100:50 to obtain the toughening agent T2 for road and bridge high-toughness epoxy.

[0089] <Preparation of road and bridge high-toughness epoxy binder>

[0090] P1. Weigh the above raw materials in the following proportions successively: liquid epoxy 128: toughening agent T2: reactive diluent 622: coupling agent KH560 = 15:75:10:1. After stirring and mixing at 60 °C for 1 h, component A of the high-toughness epoxy for road and bridge is obtained.

[0091] P2. Weigh the above raw materials in the following proportions successively: polyetheramine curing agent D230: low-molecular-weight polyamide curing agent Versamid 115 = 2:1. After stirring and mixing at 40 °C for 1 h, component B of the high-toughness epoxy for road and bridge is obtained.

[0092] P3. Weigh component A and component B of the high-toughness epoxy for road and bridge according to a mass ratio of 2:1, and stir and mix them at room temperature for 1 min to obtain the high-toughness epoxy binder B2 for road and bridge. After curing at RT / 7d, relevant performance tests are carried out, and the relevant performance is shown in Table 1.

[0093] <Preparation of High-Toughness Epoxy Mixture for Road and Bridge>

[0094] P4. Put the above-prepared high-toughness epoxy binder B2 for road and bridge and graded stone materials (Zhenjiang Maodi basalt aggregate, 5 - 10 mm: 3 - 5 mm: 1 - 3 mm: 0.075 - 1 mm: mineral powder = 25:21.5:22:23:8.5) into the mixing tank according to a mass ratio of 6:100. After stirring and mixing evenly, the high-toughness epoxy mixture M2 for road and bridge is obtained. After curing at RT / 7d, relevant performance tests are carried out, and the relevant performance is shown in Table 2.

[0095] Table 2. Performance Test Data in Example 2

[0096]

[0097]

[0098] Example 3

[0099] <Preparation of Toughening Agent for High-Toughness Epoxy for Road and Bridge>

[0100] S1. Dehydrate PPG4000 at 105 °C under N2 conditions for 2 h. Then, according to n(NCO) / n(OH) = 2.05 / 1, slowly and evenly drop MDI-100 within 2 h, and then continue to react at 80 °C under N2 conditions until the NCO content in the synthesis product reaches the theoretical value, to obtain the terminal isocyanate group polyurethane prepolymer.

[0101] S2. According to n(NCO) / n(OH)=1 / 1.05, bisphenol F glycidyl ether was added to the terminal isocyanate group polyurethane prepolymer, and 0.3 wt% of dibutyltin dilaurate was added. Then the reaction was carried out under the conditions of 80 °C and N2 until the residual NCO content in the synthesis product was ≤0.1%, and a mono-hydroxy epoxy-capped polyurethane prepolymer was prepared.

[0102] S3. According to n(NCO) / n(OH)=1 / 1.05, 2-chloro-4-nitrophenol was added to the terminal isocyanate group polyurethane prepolymer, and 0.2 wt% of N-N-N'-N'-tetramethylethylenediamine was added. Then the reaction was continued under the conditions of 80 °C and N2 until the residual NCO content in the synthesis product was ≤0.1%, and a phenol-capped polyurethane prepolymer was prepared.

[0103] S4. The mono-hydroxy epoxy-capped polyurethane prepolymer and the phenol-capped polyurethane prepolymer were mixed evenly according to the mass ratio of 100:200, and the toughening agent T3 for high-toughness epoxy for road and bridge was obtained.

[0104] <Preparation of high-toughness epoxy binder for road and bridge>

[0105] P1. The above raw materials were weighed in sequence according to the ratio of liquid epoxy 128:toughening agent T3:active diluent 748:coupling agent KH560 = 20:70:10:1, and after stirring and mixing at 60 °C for 1 h, the high-toughness epoxy component A for road and bridge was prepared.

[0106] P2. The above raw materials were weighed in sequence according to the ratio of polyetheramine curing agent D400:low molecular weight polyamide curing agent Versamid 140 = 1:2, and after stirring and mixing at 40 °C for 1 h, the high-toughness epoxy component B for road and bridge was prepared.

[0107] P3. The high-toughness epoxy component A and component B for road and bridge were weighed according to the mass ratio of 4:1, and after stirring and mixing at room temperature for 3 min, the high-toughness epoxy binder B3 for road and bridge was prepared. After curing at RT / 7d, relevant performance tests were carried out, and the relevant performance is shown in Table 1.

[0108] <Preparation of high-toughness epoxy mixture for road and bridge>

[0109] P4. The above-prepared high-toughness epoxy binder B3 for road and bridge and graded stone materials (Zhenjiang Maodi basalt aggregate, 5-10 mm:3-5 mm:1-3 mm:0.075-1 mm:mineral powder = 25:21.5:22:23:8.5) were put into a mixing tank according to the mass ratio of 8.0:100, and after stirring and mixing evenly, the high-toughness epoxy mixture M3 for road and bridge was prepared. After curing at RT / 7d, relevant performance tests were carried out, and the relevant performance is shown in Table 3.

[0110] Table 3. Performance test data in Example 3

[0111]

[0112] Example 4

[0113] <Toughening agent for preparing high-toughness epoxy for road and bridge>

[0114] S1. Dehydrate PPG1000 at 105 °C under N2 for 2 h, then gradually and evenly dropwise add MDI-100 within 2 h according to n(NCO) / n(OH) = 2.05 / 1, and then continue to react at 70 °C under N2 until the NCO content in the synthesis product reaches the theoretical value to obtain an isocyanate-terminated polyurethane prepolymer;

[0115] S2. According to n(NCO) / n(OH) = 1 / 1.05, add diglycidyl ether of glycerol to the isocyanate-terminated polyurethane prepolymer, and add 0.3 wt% of dibutyltin dimaleate, and then react at 70 °C under N2 until the residual NCO content in the synthesis product ≤ 0.1% to obtain a mono-hydroxy epoxy-capped polyurethane prepolymer;

[0116] S3. According to n(NCO) / n(OH) = 1 / 1.05, add 2-chloro-4-nitrophenol to the isocyanate-terminated polyurethane prepolymer, and add 0.5 wt% of N-N-N'-N'-tetramethyl-1,6-hexanediamine, and then continue to react at 80 °C under N2 until the residual NCO content in the synthesis product ≤ 0.1% to obtain a phenol-capped polyurethane prepolymer;

[0117] S4. Mix the mono-hydroxy epoxy-capped polyurethane prepolymer and the phenol-capped polyurethane prepolymer evenly according to the mass ratio of 100:100 to obtain the toughening agent T4 for high-toughness epoxy for road and bridge.

[0118] <Preparation of high-toughness epoxy binder for road and bridge>

[0119] P1. Weigh the above raw materials in turn according to the ratio of liquid epoxy 128: toughening agent T4: active diluent 748: coupling agent KH560 = 10:80:10:1, and stir and mix at 60 °C for 1 h to obtain the high-toughness epoxy component A for road and bridge;

[0120] P2. Weigh the above raw materials in turn according to the ratio of polyetheramine curing agent D400: low-molecular polyamide curing agent Versamid 140 = 1:1, and stir and mix at 40 °C for 1 h to obtain the high-toughness epoxy component B for road and bridge;

[0121] P3. Weigh the high-toughness epoxy component A and component B according to the mass ratio of 3:1, and stir and mix at room temperature for 2 min to obtain the high-toughness epoxy binder B4 for road and bridge. After curing at RT / 7d, conduct relevant performance tests, and the relevant performance is shown in Table 1.

[0122] <Preparation of High-Toughness Epoxy Mixture for Road and Bridge>

[0123] P4. Put the prepared high-toughness epoxy binder B4 for road and bridge and graded stone materials (Zhenjiang Maodi basalt aggregate, 5 - 10mm: 3 - 5mm: 1 - 3mm: 0.075 - 1mm: mineral powder = 25:21.5:22:23:8.5) into the mixing tank according to the mass ratio of 7.5:100. After stirring and mixing evenly, obtain the high-toughness epoxy mixture M4 for road and bridge. Conduct relevant performance tests after curing at RT / 7d. The relevant performance is shown in Table 4.

[0124] Table 4. Performance Test Data in Example 4

[0125]

[0126] Comparative Example 1

[0127] <Preparation of Toughness-Enhancing Agent for High-Toughness Epoxy for Road and Bridge>

[0128] S1. Dehydrate PPG1000 at 105°C under N2 conditions for 2h. Then, gradually and evenly drop TDI-80 within 2h according to n(NCO) / n(OH) = 2.05 / 1. Then continue to react at 70°C under N2 conditions until the NCO content in the synthetic product reaches the theoretical value to obtain an isocyanate-terminated polyurethane prepolymer.

[0129] S2. According to n(NCO) / n(OH) = 1 / 1.05, put bisphenol A glycidyl ether into the isocyanate-terminated polyurethane prepolymer, and add 0.5wt% dibutyltin dilaurate. Then react at 70°C under N2 conditions until the residual NCO content in the synthetic product ≤ 0.1% to obtain a mono-hydroxy epoxy-capped polyurethane prepolymer, which is the toughness-enhancing agent T1-1 for high-toughness epoxy for road and bridge.

[0130] <Preparation of High-Toughness Epoxy Binder for Road and Bridge>

[0131] The toughness-enhancing agent for high-toughness epoxy for road and bridge is T1-1, and the prepared high-toughness epoxy binder is B1-1. Its preparation process is the same as that in Example 1. Conduct relevant performance tests after curing at RT / 7d. The relevant performance is shown in Table 1.

[0132] <Preparation of High-Toughness Epoxy Mixture for Road and Bridge>

[0133] The prepared high-toughness epoxy mixture for road and bridge is M1-1. Its preparation process is the same as that in Example 1. Conduct relevant performance tests after curing at RT / 7d. The relevant performance is shown in Table 5.

[0134] Table 5. Performance Test Data in Comparative Example 1

[0135]

[0136] Compared with Example 1, in Comparative Example 1, the high-toughness epoxy toughening agent for road and bridge is completely composed of a mono-hydroxy epoxy-capped polyurethane prepolymer. Due to the lack of phenol-capped polyurethane prepolymer in the toughening agent, the road and bridge high-toughness epoxy binder only forms a rigid network composed of macromolecular epoxy and small-molecular epoxy. The cured product has sufficient strength but insufficient deformation ability. The tensile strength of the prepared binder B1-1 reaches 18.2 MPa, while the elongation at break is only 45%, and the temperature range of ΔTTanδ>0.3 is only 25.6 - 56.3 °C; the Marshall stability of the prepared mixture M1-1 at 60 °C exceeds 100 kN, the ultimate flexural tensile strain of the beam at -10 °C is only 1933, and the four-point bending fatigue life at 15 °C, 10 Hz, and 800 με is less than 1 million times, which cannot meet the usage requirements of the key paving materials for road and bridge paving.

[0137] Comparative Example 2

[0138] <Preparation of toughening agent for high-toughness epoxy for road and bridge>

[0139] S1. Dehydrate PPG2000 at 105 °C under N2 for 2 h, and then gradually and uniformly drop TDI-80 within 2 h according to n(NCO) / n(OH)=2.05 / 1. Then continue to react at 80 °C under N2 until the NCO content in the synthesis product reaches the theoretical value to obtain an isocyanate-terminated polyurethane prepolymer.

[0140] S2. Put methyl 3-chloro-4-hydroxybenzoate into the isocyanate-terminated polyurethane prepolymer according to n(NCO) / n(OH)=1 / 1.05, and add 0.5 wt% of N-N'-dimethylaminocyclohexylamine. Then continue to react at 40 °C under N2 until the residual NCO content in the synthesis product ≤0.1% to obtain a phenol-capped polyurethane prepolymer, which is the toughening agent T2-1 for high-toughness epoxy for road and bridge.

[0141] <Preparation of high-toughness epoxy binder for road and bridge>

[0142] The toughening agent for high-toughness epoxy for road and bridge is T2-1, and the prepared high-toughness epoxy binder for road and bridge is B2-1. The preparation process is the same as that in Example 2. After curing at RT / 7d, relevant performance tests are carried out, and the relevant performance is shown in Table 1.

[0143] <Preparation of high-toughness epoxy mixture for road and bridge>

[0144] The prepared high-toughness epoxy mixture for road and bridge is M2-1. The preparation process is the same as that in Example 2. After curing at RT / 7d, relevant performance tests are carried out, and the relevant performance is shown in Table 6.

[0145] Table 6. Performance test data in Comparative Example 2

[0146]

[0147] Compared with Example 2, the high-toughness epoxy toughening agent for road and bridge in Comparative Example 2 is completely composed of phenol-terminated polyurethane prepolymer. Due to the lack of mono-hydroxy epoxy-terminated polyurethane prepolymer in the toughening agent, the road and bridge high-toughness epoxy binder forms a flexible network mainly composed of macromolecular polyurethane network and supplemented by small-molecular epoxy network. The cured product has sufficient deformation ability but insufficient strength. The tensile strength of the prepared binder B2-1 is only 1.1 MPa, while the elongation at break is as high as 422%, and the temperature range of ΔTTanδ>0.3 is only -21.7 to 45.4 °C; the Marshall stability of the prepared mixture M2-1 at 60 °C is only 35.3 kN, the ultimate flexural tensile strain of the small beam at -10 °C is as high as 13223, and the four-point bending fatigue life at 15 °C, 10 Hz, and 800 με is greater than 1 million times, which cannot meet the use requirements of the key paving materials for road and bridge paving.

[0148] Comparative Example 3

[0149] <Preparation of toughening agent for high-toughness epoxy for road and bridge>

[0150] S1. Dehydrate PPG4000 at 105 °C under N2 for 2 h, then gradually and uniformly drop MDI-100 within 2 h according to n(NCO) / n(OH)=2.05 / 1, and then continue to react at 80 °C under N2 until the NCO content in the synthesis product reaches the theoretical value to obtain an isocyanate-terminated polyurethane prepolymer.

[0151] S2. Add bisphenol F glycidyl ether to the isocyanate-terminated polyurethane prepolymer according to n(NCO) / n(OH)=1 / 1.05, and add 0.3 wt% of dibutyltin dioleate, then react at 80 °C under N2 until the residual NCO content in the synthesis product ≤0.1% to obtain a mono-hydroxy epoxy-terminated polyurethane prepolymer.

[0152] S3. Add phenol to the isocyanate-terminated polyurethane prepolymer according to n(NCO) / n(OH)=1 / 1.05, and add 0.2 wt% of N-N-N'-N'-tetramethylethylenediamine, then continue to react at 80 °C under N2 until the residual NCO content in the synthesis product ≤0.1% to obtain a phenol-terminated polyurethane prepolymer.

[0153] S4. Mix the mono-hydroxy epoxy-terminated polyurethane prepolymer and the phenol-terminated polyurethane prepolymer evenly according to a mass ratio of 100:200 to obtain the toughening agent T3-1 for high-toughness epoxy for road and bridge.

[0154] <Preparation of high-toughness epoxy binder for road and bridge>

[0155] The toughening agent for road and bridge high-toughness epoxy is T3-1, and the prepared road and bridge high-toughness epoxy binder is B3-1. The preparation process is the same as that of Example 3. Given that the road and bridge high-toughness epoxy binder is B3-1 under normal temperature conditions, a high-temperature curing process (120°C / 1d + RT / 3d) is used for curing, and its related properties are shown in Table 1.

[0156] <Preparation of Road and Bridge High-Toughness Epoxy Mixture>

[0157] The prepared road and bridge high-toughness epoxy mixture is M3-1. The preparation process is the same as that of Example 3, and a high-temperature curing process (120°C / 1d + RT / 3d) is used for curing, and its related properties are shown in Table 7.

[0158] Table 7. Performance Test Data in Comparative Example 3

[0159]

[0160]

[0161] Note: e - The curing conditions of the binder and mixture in Comparative Example 3 are 120°C / 1d + RT / 3d.

[0162] Compared with Example 3, the high-toughness epoxy toughening agent for road and bridge in Comparative Example 3 is composed of a mono-hydroxy epoxy-capped polyurethane prepolymer and a phenol-capped polyurethane prepolymer. Since phenol is used as the capping agent, the de-capping temperature of the prepared phenol-capped polyurethane prepolymer is as high as 130°C. However, road and bridge high-toughness epoxy is usually cured at normal temperature and cannot reach the de-capping temperature of the phenol-capped polyurethane prepolymer. Therefore, the phenol-capped polyurethane prepolymer does not de-cap during the curing process of road and bridge high-toughness epoxy, and the prepared road and bridge high-toughness epoxy binder B3-1 does not cure at normal temperature and cannot meet the usage requirements of key paving materials for road and bridge paving. However, if the road and bridge high-toughness epoxy binder B3-1 is cured at high temperature (120°C / 1d + RT / 3d), its mechanical properties are equivalent to those of other Example 3.

[0163] Comparative Example 4

[0164] <Preparation of Toughening Agent for Road and Bridge High-Toughness Epoxy>

[0165] S1. Dehydrate PPG1000 at 105°C under N2 conditions for 2h, and then gradually and uniformly drop MDI-100 within 2h according to n(NCO) / n(OH) = 2.05 / 1. Then continue to react at 70°C under N2 conditions until the NCO content in the synthesis product reaches the theoretical value to obtain a terminal isocyanate group polyurethane prepolymer;

[0166] S2. According to n(NCO) / n(OH) = 1 / 1.05, add diglycidyl ether of glycerol to the terminal isocyanate group polyurethane prepolymer, and add 0.3 wt% of dibutyltin dimaleate. Then react under the conditions of 70 °C and N2 until the residual NCO content in the synthesized product is ≤ 0.1% to obtain a mono-hydroxy epoxy-capped polyurethane prepolymer;

[0167] S3. Mix the mono-hydroxy epoxy-capped polyurethane prepolymer and the terminal isocyanate group polyurethane prepolymer evenly according to the mass ratio of 100:100, which is the toughening agent T4-1 for high-toughness epoxy for road and bridge.

[0168] <Preparation of high-toughness epoxy binder for road and bridge>

[0169] The toughening agent for high-toughness epoxy for road and bridge is T4-1, and the prepared high-toughness epoxy binder for road and bridge is B4-1. The preparation process is the same as that in Example 4. After curing at RT / 7d, relevant performance tests are carried out, and the relevant performance is shown in Table 1.

[0170] <Preparation of high-toughness epoxy mixture for road and bridge>

[0171] The prepared high-toughness epoxy mixture for road and bridge is M4-1. The preparation process is the same as that in Example 3. After curing at RT / 7d, relevant performance tests are carried out, and the relevant performance is shown in Table 8.

[0172] Table 8. Performance test data in Comparative Example 4

[0173]

[0174] Compared with Example 4, the high-toughness epoxy toughening agent for road and bridge in Comparative Example 4 is composed of a mono-hydroxy epoxy-capped polyurethane prepolymer and a terminal isocyanate group polyurethane prepolymer. Since the toughening agent contains a terminal isocyanate group polyurethane prepolymer with high reactivity, a rapid gel reaction occurs about 20 min after it is mixed with the epoxy curing agent, which cannot meet the technical requirements of workability for road and bridge paving.

[0175] Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A toughening agent for high-toughness epoxy used in road and bridge, characterized in that, It includes a mono-hydroxy epoxy-terminated polyurethane prepolymer and a phenol-terminated polyurethane prepolymer with a mass ratio of 100:50 to 200. The mono-hydroxy epoxy-terminated polyurethane prepolymer is prepared by blocking the terminal isocyanate group of the polyurethane prepolymer through the reaction of a mono-hydroxy epoxy compound with the isocyanate group under the action of catalyst I. The phenol-terminated polyurethane prepolymer can be de-blocked under the synergistic action of 40 - 80 °C and an amine curing agent to form a phenolic compound and a terminal isocyanate group polyurethane prepolymer; the amine curing agent is a mixture of a polyetheramine curing agent and a low molecular weight polyamide curing agent. The phenol-terminated polyurethane prepolymer is prepared by blocking the terminal isocyanate group of the polyurethane prepolymer with a phenolic compound under the action of catalyst II. The phenolic compound is a substituted phenol, and its molecular structure general formula is as follows. ； In the formula, X is H, Cl, NO2, COOCH3; Y is H, Cl, NO2, COOCH3, where X and Y cannot be H at the same time.

2. The toughening agent for high-toughness epoxy used in road and bridge, as claimed in claim 1, wherein The catalyst I is one or more of dibutyltin dilaurate, stannous octoate, dibutyltin dioleate, and dibutyltin dimaleate.

3. The toughening agent for high-toughness epoxy used in road and bridge, as claimed in claim 1, is characterized in that The mono-hydroxy epoxy compound is one or more of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, butanediol monoglycidyl ether, hexanediol monoglycidyl ether, glycerol diglycidyl ether, pentaerythritol triglycidyl ether, and trimethylolpropane diglycidyl ether.

4. The toughening agent for high-toughness epoxy used in road and bridge, as described in claim 1, is characterized in that The catalyst II is one or more of N,N’-dimethyldodecylamine, N,N’-dimethylaminocyclohexane, N,N,N’,N’-tetramethylethylenediamine, and N,N,N’,N’-tetramethyl-1,6-hexanediamine.

5. The preparation method of the toughening agent for high-toughness epoxy used in road and bridge, as claimed in claim 1, is characterized in that: It includes the following operation steps: S1. React an excessive polyisocyanate with a polyol to obtain the terminal isocyanate group polyurethane prepolymer. S2. Add the mono-hydroxy epoxy compound and the catalyst I to the product of S1 to obtain the mono-hydroxy epoxy-terminated polyurethane prepolymer. S3. Add the phenolic compound and the catalyst II to the product of S1 to obtain the phenol-terminated polyurethane prepolymer. S4. Mix the mono-hydroxy epoxy-terminated polyurethane prepolymer in S2 and the phenol-terminated polyurethane prepolymer in S3 evenly to obtain the toughening agent for road and bridge high-toughness epoxy.

6. The usage method of the toughening agent for high-toughness epoxy used in road and bridge, as described in claim 1, is characterized in that: It includes the following operation steps: P1. Stir and mix liquid epoxy resin, the toughening agent for road and bridge high-toughness epoxy, an active diluent, and a coupling agent evenly to obtain the road and bridge high-toughness epoxy component A. P2. Stir and mix the polyetheramine curing agent and the low molecular weight polyamide curing agent evenly to obtain the road and bridge high-toughness epoxy component B. P3. Stir and mix the road and bridge high-toughness epoxy component A in P1 and the road and bridge high-toughness epoxy component B in P2 evenly to obtain the road and bridge high-toughness epoxy binder. P4. Stir and mix the road and bridge high-toughness epoxy binder in P3 and graded stone materials evenly to obtain the road and bridge high-toughness epoxy mixture.

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