A star-shaped polyurethane and graphene oxide composite material, preparation method and application

Abstract

The present application discloses a star-shaped polyurethane and graphene oxide composite material, a preparation method and an application, which include reacting a dibasic primary amine, an epoxide, ε-caprolactone and a diisocyanate to obtain a star-shaped polyurethane; reacting graphene oxide and the star-shaped polyurethane to obtain a star-shaped polyurethane and graphene oxide composite material. In the present application, the graphene oxide is modified by the star-shaped polyurethane, so that the star-shaped polyurethane and graphene oxide composite material is easy to be uniformly dispersed in asphalt, the dispersion time is reduced, and the star-shaped polyurethane molecules are not easily entangled. When applied to an asphalt system, swelling can occur and a through-network structure can be formed with asphalt molecules. The soft segment structure of the star-shaped polyurethane can effectively improve the low-temperature performance of the asphalt system.

Description

Technical Field

[0001] This application relates to the technical field of modified asphalt, and particularly relates to a star-shaped polyurethane and graphene oxide composite material, a preparation method and an application thereof. Background Art

[0002] In the field of road asphalt, adding graphene to asphalt can improve the softening point, penetration, rutting resistance and anti-aging properties of asphalt, and can also effectively inhibit the release of asphalt fumes, which is beneficial to environmental protection; however, the high specific surface area of graphene makes it difficult to disperse in a highly viscous asphalt system, and the introduction of the rigid structure of graphene will cause a decrease in the ductility performance of asphalt. Summary of the Invention

[0003] In view of the problems existing in the above-mentioned prior art, this application provides a star-shaped polyurethane and graphene oxide composite material, a preparation method and an application thereof, which are easy to disperse uniformly in asphalt and can effectively improve the low-temperature performance of the asphalt system when applied to the asphalt system. The technical solutions are as follows:

[0004] This application provides a preparation method of a star-shaped polyurethane and graphene oxide composite material, including:

[0005] Reacting a diamine, an epoxide, ε-caprolactone and a diisocyanate to obtain a star-shaped polyurethane;

[0006] Reacting graphene oxide and the star-shaped polyurethane to obtain a star-shaped polyurethane and graphene oxide composite material.

[0007] Further, the mass ratio of the diamine, the epoxide, the ε-caprolactone and the diisocyanate is (1-2):(5-10):(2-6):(12-25).

[0008] Further, the step of reacting a diamine, an epoxide, ε-caprolactone and a diisocyanate to obtain a star-shaped polyurethane includes:

[0009] Reacting the diamine, the epoxide and the ε-caprolactone to obtain a star-shaped hydroxyl resin;

[0010] Carrying out a catalytic reaction on a preset amount of the diisocyanate and the star-shaped hydroxyl resin to obtain the star-shaped polyurethane.

[0011] Further, the step of reacting a diamine, an epoxide and ε-caprolactone to obtain a star-shaped hydroxyl resin includes:

[0012] Carrying out a ring-opening reaction on the diamine and the epoxide to obtain a ring-opening intermediate;

[0013] The ε-caprolactone and the ring-opening intermediate are subjected to a ring-opening esterification reaction to obtain the star-shaped hydroxyl resin.

[0014] Further, the epoxy compound includes any one of glycidyl versatate, benzyl glycidyl ether and C12 alkyl glycidyl ether.

[0015] Further, the diisocyanate includes any one of hexamethylene diisocyanate, toluene diisocyanate and isophorone diisocyanate.

[0016] Further, the mass ratio of the star-shaped polyurethane to the graphene oxide is (5-40):1.

[0017] Further, the median particle size of the graphene oxide is less than 5 μm.

[0018] The present application also provides a star-shaped polyurethane and graphene oxide composite material, and the star-shaped polyurethane and graphene oxide composite material is obtained by the preparation method described in any one of the above.

[0019] The present application also provides an application of the star-shaped polyurethane and graphene oxide composite material as described above in modified asphalt, and the mass ratio of the star-shaped polyurethane and graphene oxide composite material to the asphalt is (0.01-0.6):1.

[0020] Implementing the present application has the following beneficial effects:

[0021] 1. In the present application, the graphene oxide is modified by the star-shaped polyurethane, so that the star-shaped polyurethane and graphene oxide composite material is easy to be uniformly dispersed in the asphalt and the dispersion time is reduced; moreover, the star-shaped polymer structure of the star-shaped polyurethane makes the polyurethane molecules not easily entangled, and when applied to the asphalt system, it can swell and form a through-network structure with the asphalt molecules, and the soft segment structure of the polyurethane molecules can effectively improve the low-temperature performance of the asphalt system.

[0022] 2. The star-shaped polyurethane and graphene oxide composite material of the present application can be more efficiently and rapidly and uniformly dispersed in the asphalt system. On the one hand, the graphene oxide sheets can block UV and oxygen molecules from entering the asphalt to enhance the anti-aging performance of the asphalt; on the other hand, the graphene oxide can improve the surface free energy and internal healing performance of the asphalt to enhance the adhesion of the asphalt binder and the adhesion of the asphalt-aggregate, and slow down the influence of aging on the reduction of the adhesion of the asphalt-aggregate interface; in addition, the graphene oxide sheets hinder the mobility of the asphalt molecular segments at high temperatures, which can improve the high-temperature performance, flow performance and anti-aging performance of the asphalt. Description of the Drawings

[0023] To more clearly illustrate the technical solution of the present application, the accompanying drawings used in the embodiments will be briefly introduced below, where the same components are denoted by the same reference numerals. Obviously, the drawings in the following description are only some embodiments of the present application, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0024] Figure 1 It is a flowchart of a preparation method of a star-shaped polyurethane and graphene oxide composite material in a possible implementation manner of the present application;

[0025] Figure 2 It is a schematic diagram of the unit structure of the star-shaped polyurethane molecule provided by the present application;

[0026] Figure 3 It is a partial schematic diagram of a through-grid structure formed by swelling a star-shaped polyurethane and graphene oxide composite material in asphalt provided by the present application. Detailed implementation manners

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments, and thus should not be construed as a limitation to the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0028] It should be noted that the terms "first", "second", etc. in the specification, claims and drawings of the present application are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than the following illustrations or descriptions. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product including a series of steps or units does not necessarily need to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0029] Embodiment 1

[0030] The present application provides a preparation method of a star-shaped polyurethane and graphene oxide composite material. As shown in the Figure 1 specification appendix, the preparation method includes:

[0031] S1, reacting a diamine, an epoxide, ε-caprolactone and a diisocyanate to obtain a star-shaped polyurethane;

[0032] S2. React graphene oxide with the star-shaped polyurethane to obtain a star-shaped polyurethane / graphene oxide composite material.

[0033] Optionally, the diamine includes any one of 4,4'-diaminodicyclohexylmethane (PACM) and 1,6-hexanediamine (HDA).

[0034] Optionally, the epoxy compound includes any one of glycidyl versatate (E10P), benzyl glycidyl ether (BGE), and C12 alkyl glycidyl ether (C12GE).

[0035] Optionally, the diisocyanate includes any one of hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), and isophorone diisocyanate (IPDI).

[0036] Specifically, in an alternative embodiment, the mass ratio of the diamine, epoxy compound, ε-caprolactone, and diisocyanate is (1-2):(5-10):(2-6):(12-25). Within this mass ratio range, star-shaped polyurethane can be stably formed, which is beneficial to improving the reaction rate and yield and enhancing the reaction stability. Further, in another alternative embodiment, the mass ratio of the diamine, epoxy compound, ε-caprolactone, and diisocyanate is (1-2):(6-8):(2-4):(13-20). For example, in a specific embodiment, 10-20 parts by mass of the diamine, 60-80 parts by mass of the epoxy compound, 20-40 parts by mass of ε-caprolactone, and 130-200 parts by mass of the diisocyanate are weighed and reacted to form star-shaped polyurethane. In a preferred embodiment, the mass ratio of the diamine, epoxy compound, ε-caprolactone, and diisocyanate is (1-2):(6-8):(2-4):(13-17).

[0037] Specifically, in an alternative embodiment, step S1, i.e., reacting the diamine, epoxy compound, ε-caprolactone, and diisocyanate to obtain star-shaped polyurethane, includes:

[0038] React the diamine, epoxy compound, and ε-caprolactone to obtain a star-shaped hydroxyl resin.

[0039] Carry out a catalytic reaction on a preset amount of the diisocyanate and the star-shaped hydroxyl resin to obtain the star-shaped polyurethane.

[0040] Specifically, in an alternative embodiment, reacting the diamine, epoxy compound, and ε-caprolactone to obtain a star-shaped hydroxyl resin includes:

[0041] Carry out a ring-opening reaction on the diamine and the epoxy compound to obtain a ring-opening intermediate.

[0042] The ring-opening esterification reaction is carried out on the ε-caprolactone and the ring-opening intermediate to obtain the star-shaped hydroxyl resin.

[0043] Among them, first, the ring-opening reaction is carried out on the dibasic primary amine and the epoxy compound, so that the active hydrogen on the dibasic primary amine reacts with the epoxy group of the epoxy compound, and the dibasic primary amine undergoes ring-opening to obtain a secondary amine, and the secondary amine is the ring-opening intermediate; in a possible embodiment, a preset amount of epoxy compound is gradually added to the dibasic primary amine, and the epoxy compound is added when the dibasic primary amine is in a stirring state to improve the mixing uniformity of the two, which is beneficial to improving the reaction rate and conversion rate of the ring-opening reaction; optionally, the mixing temperature for adding the epoxy compound is 30-50°C, and the duration is 1.5-2.5 h; alternatively, the mixing temperature for adding the epoxy compound is 35-45°C, and the duration is 2-2.5 h; in a specific embodiment, the mixing temperature for adding the epoxy compound is 40°C, and the duration is 2 h.

[0044] Specifically, in an alternative embodiment, the reaction temperature of the ring-opening reaction is 70-90°C, and the time is 3-5 h. On the one hand, it avoids too slow reaction or even no reaction due to too low temperature, and on the other hand, it avoids too fast reaction due to too high temperature, resulting in uneven products; alternatively, the reaction temperature is 75-85°C, and the time is 3.5-4.5 h; for example, in a specific embodiment, the reaction temperature of the ring-opening reaction is 80°C, and the reaction time is 4 h.

[0045] Specifically, after the ring-opening reaction, a preset amount of ε-caprolactone is continuously added to the reaction system, so that the ring lactone structure of ε-caprolactone reacts with the secondary amine to carry out ring-opening esterification reaction to generate star-shaped hydroxyl resin. Among them, the reaction temperature of the ring-opening esterification reaction is 110-130°C, and the reaction time is 7.5-8.5 h, which improves the reaction rate, avoids uneven polymerization, inhibits the generation of by-products, and improves the reaction reliability and product purity; in an alternative embodiment, the reaction temperature is 115-125°C; in a specific embodiment, the reaction temperature is 120°C, and the reaction time is 8 h, and the ring-opening esterification reaction proceeds stably, which not only generates enough star-shaped hydroxyl resin and the product is relatively uniform, but also avoids wasting energy due to too long reaction time.

[0046] Specifically, in a possible embodiment, a catalyst is added to the star-shaped hydroxyl resin, and then a preset amount of diisocyanate is gradually added under the temperature of 50-70°C and stirring conditions, and then the temperature is raised to 70-90°C for catalytic reaction, and the reaction time is 3-5 h; among them, the isocyanate group in the diisocyanate is in excess, so that the reaction of the star-shaped hydroxyl resin and the diisocyanate can generate star-shaped polyurethane containing terminal isocyanate groups, such as Figure 2As shown, the star-shaped polyurethane is a star-shaped polyurethane with isocyanate groups (-NCO) at both ends, that is, one isocyanate group is connected to each end of the star-shaped polyurethane, so as to facilitate subsequent connection of graphene oxide for surface graft modification of graphene oxide.

[0047] Optionally, the catalyst includes any one of dibutyltin dilaurate, zirconium acetylacetonate, stannous octoate, and 1,4-diazabicyclo[2,2,2]octane.

[0048] Optionally, the catalytic temperature is 75-85 °C. On the one hand, it avoids the reaction being too slow or even unable to proceed, and on the other hand, it avoids uneven polymerization and too large a molecular weight distribution of the product. For example, in a specific embodiment, the catalytic temperature is 80 °C and the reaction time is 4 h.

[0049] Specifically, in a possible embodiment, a preset amount of graphene oxide is added to the star-shaped polyurethane to obtain a star-shaped polyurethane / graphene oxide composite material. Optionally, the mass ratio of the star-shaped polyurethane to graphene oxide is (5-40):1. Optionally, the mass ratio of the star-shaped polyurethane to graphene oxide is (5-35):1. Within this mass ratio range, the oxygen-containing functional groups of graphene oxide and the isocyanate groups on the star-shaped polyurethane undergo graft copolymerization to form stable chemical bonds, and the reaction can proceed quickly and stably to improve the yield of the star-shaped polyurethane / graphene oxide composite material.

[0050] Optionally, the reaction temperature of the star-shaped polyurethane and graphene oxide is 50-70 °C, and the reaction time is 3.5-4.5 h under stirring conditions, which not only ensures that the reaction has a sufficient reaction rate but also avoids uneven polymerization. Optionally, the reaction temperature is 55-65 °C. In a preferred embodiment, the reaction temperature is 60 °C and the stirring reaction is 4 h, so that the isocyanate groups react with graphene oxide to obtain a star-shaped polyurethane / graphene oxide composite material.

[0051] Specifically, the oxygen content of graphene oxide is greater than 40 wt%, which is used to provide more hydroxyl sites. The hydroxyl sites can connect more star-shaped polyurethanes to modify graphene oxide, which is beneficial to improving the dispersion uniformity of the star-shaped polyurethane / graphene oxide composite material in asphalt. The median particle size D50 of the graphene oxide is less than 5 μm. At this median particle size, the modified graphene oxide can be dispersed into asphalt more quickly and evenly. The specific surface area of the graphene oxide is greater than 200 m 2 / g, so that the graphene uniformly dispersed in asphalt after modification can play a better shielding role to block UV, oxygen molecules, etc. from entering the asphalt system, greatly improving the anti-aging performance of asphalt.

[0052] This embodiment also provides a star-shaped polyurethane and graphene oxide composite material (hereinafter referred to as the composite material), which is obtained by the preparation method of the star-shaped polyurethane and graphene oxide composite material described above. This composite material combines the star-shaped polymer structure of star-shaped polyurethane to modify graphene oxide, greatly improving the dispersion speed and dispersion uniformity of the composite material in asphalt, and also making the molecular chains of the composite material itself not easily entangled. Moreover, after the composite material is added to the asphalt system, it can greatly improve the low-temperature performance of asphalt.

[0053] This embodiment also provides an application of the star-shaped polyurethane and graphene oxide composite material in modified asphalt and a star-shaped polyurethane and graphene oxide composite material modified asphalt. As Figure 3 shown, when the composite material is added to asphalt, it swells to form a huge polymer network, which can penetrate with asphalt molecules, so that the composite material and asphalt form a penetrating grid structure to obtain modified asphalt. In this modified asphalt, the composite material and asphalt molecules are in a penetrating grid structure. Among them, there is less entanglement between the molecular chains of the composite material, and it has good solubility and fluidity, and can be more efficiently and uniformly dispersed in asphalt, with short dispersion time and uniform dispersion, greatly improving the performance of modified asphalt. At the same time, star-shaped polyurethane has strong low-temperature deformation ability, especially the soft segment structure in star-shaped polyurethane. The soft segment structure is the molecular chain segment formed by low-molecular-weight (1000-2000) polyester or polyether in star-shaped polyurethane molecules, with large flexibility, which greatly enhances the low-temperature performance of modified asphalt. In addition, the uniformly dispersed graphene sheets can block UV, oxygen molecules, etc. from entering the modified asphalt system, greatly improving the anti-aging performance of modified asphalt. The addition of graphene oxide improves the surface free energy and internal healing performance of modified asphalt, can greatly improve the adhesion of modified asphalt binder and the adhesion of modified asphalt-aggregate, and significantly slows down the influence of aging on the reduction of the interfacial adhesion of modified asphalt-aggregate. Moreover, graphene oxide can hinder the activity of asphalt molecular chains at high temperatures, thereby improving the high-temperature performance, rheological performance and anti-aging performance of modified asphalt.

[0054] Specifically, the mass ratio of the star-shaped polyurethane and graphene oxide composite material to asphalt is (0.01-0.6):1. That is, when using this composite material to modify asphalt, the mass ratio of the composite material to asphalt is (0.01-0.6):1. Within this mass ratio range, the low-temperature performance of modified asphalt can be greatly improved. In a preferred embodiment, the mass ratio of the composite material to asphalt is (0.01-0.06):1. The dosage of this composite material is small, but using a small amount of the composite material can greatly enhance the low-temperature performance of modified asphalt.

[0055] Specifically, in an alternative embodiment, a preset amount of composite material is added to asphalt and subjected to high-speed shearing. The shearing temperature is 150 - 170 °C, the shearing speed is 3800 - 4500 r / min, and the shearing time is 8 - 15 min, which can improve the dispersion speed of the composite material into asphalt, further shorten the dispersion time, and also contribute to improving the dispersion uniformity.

[0056] In a specific embodiment, asphalt is modified with a star-shaped polyurethane and graphene oxide composite material to obtain modified asphalt. The preparation method includes the following steps:

[0057] Weigh 17.43 parts by mass of hexamethylenediamine into a reaction vessel, and constantly drop 73.5 parts by mass of glycidyl versatate (E10P) at a constant speed under mechanical stirring at 40 °C. The dropping is completed in 2 h, and then the temperature is raised to 80 °C and the reaction continues for 4 h;

[0058] Weigh 34.2 parts by mass of ε-caprolactone into a reaction vessel, continuously stir and raise the temperature to 120 °C for reaction for 8 h to obtain a star-shaped hydroxyl resin;

[0059] Add 0.1 part by mass of dibutyltin dilaurate to the reaction vessel, lower the temperature to 60 °C and stir for dispersion, then dropwise add 151 parts by mass of hexamethylene diisocyanate (HDI). The dropping is completed in 2 h, and then the temperature is raised to 80 °C and the reaction continues for 4 h to obtain a star-shaped polyurethane with terminal isocyanate groups;

[0060] Add 30 parts by mass of graphene oxide powder to the star-shaped polyurethane, and stir and react at 60 °C for 4 h to obtain a star-shaped polyurethane and graphene oxide composite material;

[0061] Add the star-shaped polyurethane and graphene oxide composite material to the asphalt system at 4% of the asphalt mass parts, and disperse it at a high speed of 4000 r / min at 160 °C for 10 min to obtain a star-shaped polyurethane and graphene oxide composite material modified asphalt.

[0062] Example 2

[0063] The difference between this example and Example 1 is that the preset amount of diisocyanate is 200 parts by mass of IPDI, and the rest is the same as in Example 1.

[0064] Example 3

[0065] The difference between this example and Example 1 is that the mass parts of the star-shaped polyurethane and graphene oxide composite material are 3% of the asphalt mass parts, and the rest is the same as in Example 1.

[0066] Example 4

[0067] The difference between this embodiment and Embodiment 1 is that the mass fraction of the star-shaped polyurethane and graphene oxide composite material is 5% of the mass fraction of the asphalt, and the rest is the same as Embodiment 1.

[0068] The properties of the modified asphalt, matrix asphalt, and 5% BSB modified asphalt in Embodiments 1 to 4 were tested respectively. The test contents included penetration, softening point, ductility, penetration ratio and ductility after aging, and rutting factor. The performance test results are shown in Table 1.

[0069] Among them, compared with the matrix asphalt and 5% BSB modified asphalt, the penetration of the star-shaped polyurethane and graphene oxide composite material modified asphalt in this application is significantly reduced, and the ductility is increased, indicating that the modified asphalt is harder and has good plasticity, and has better road performance at lower temperatures, which can reduce the generation of cracks on the asphalt pavement and reduce friction noise; moreover, the softening point is greatly increased, and the high-temperature performance is greatly enhanced; and the penetration ratio of the star-shaped polyurethane and graphene oxide composite material modified asphalt after aging is significantly higher than that of the matrix asphalt and 5% BSB modified asphalt. The penetration ratio reflects the change in penetration before and after the aging experiment. The larger the penetration ratio, the better the aging resistance. At the same time, the ductility after aging has also been improved, that is, the anti-aging performance is also better than that of the matrix asphalt and 5% BSB modified asphalt; in addition, the test data of the rutting factor are also higher than those of the matrix asphalt and 5% BSB modified asphalt, indicating that the rutting resistance of the star-shaped polyurethane and graphene oxide composite material modified asphalt has also been significantly improved, and the anti-permanent deformation performance is excellent.

[0070] It can be seen that compared with the matrix asphalt and SBS modified asphalt, the star-shaped polyurethane and graphene oxide composite material modified asphalt has been greatly improved in terms of low-temperature performance, high-temperature performance, aging resistance, and anti-permanent deformation performance.

[0071] Table 1 Performance test results of the star-shaped polyurethane and graphene oxide composite material modified asphalt, matrix asphalt, and 5% BSB modified asphalt in Embodiments 1 to 4

[0072]

[0073]

[0074] The above description only shows some embodiments of the present application and is not intended to limit the present application. Those skilled in the art should understand that the present application will have various changes and improvements, and any modifications, equivalent replacements, and improvements made in accordance with the present application fall within the scope of protection required by the present application.

Claims

1. A preparation method of a star-shaped polyurethane and graphene oxide composite material, characterized in that, Comprising: Reacting a binary primary amine, an epoxide, ε-caprolactone and a diisocyanate to obtain a star-shaped polyurethane; the mass ratio of the binary primary amine, the epoxide, the ε-caprolactone and the diisocyanate is (1-2):(5-10):(2-6):(12-25); Reacting graphene oxide and the star-shaped polyurethane to obtain a star-shaped polyurethane / graphene oxide composite material; the mass ratio of the star-shaped polyurethane to the graphene oxide is (5-40):

1.

2. The preparation method according to claim 1, characterized in that, The step of reacting a binary primary amine, an epoxide, ε-caprolactone and a diisocyanate to obtain a star-shaped polyurethane comprises: Reacting the binary primary amine, the epoxide and the ε-caprolactone to obtain a star-shaped hydroxyl resin; Carrying out a catalytic reaction on a preset amount of the diisocyanate and the star-shaped hydroxyl resin to obtain the star-shaped polyurethane.

3. The preparation method according to claim 2, wherein The step of reacting a binary primary amine, an epoxide and ε-caprolactone to obtain a star-shaped hydroxyl resin comprises: Carrying out a ring-opening reaction on the binary primary amine and the epoxide to obtain a ring-opening intermediate; Carrying out a ring-opening esterification reaction on the ε-caprolactone and the ring-opening intermediate to obtain the star-shaped hydroxyl resin.

4. The preparation method according to claim 1, wherein The epoxide comprises any one of glycidyl versatate, benzyl glycidyl ether and C12 alkyl glycidyl ether.

5. The preparation method according to claim 1, characterized in that, The diisocyanate comprises any one of hexamethylene diisocyanate, toluene diisocyanate and isophorone diisocyanate.

6. The preparation method according to claim 1, characterized in that, The median particle size of the graphene oxide is less than 5 μm.

7. A star-shaped polyurethane and graphene oxide composite material, characterized in that, The star-shaped polyurethane / graphene oxide composite material is obtained by the preparation method according to any one of claims 1-6.

8. Application of the star-shaped polyurethane and graphene oxide composite material as described in claim 7 in modified asphalt, characterized in that, The mass ratio of the star-shaped polyurethane / graphene oxide composite material to the asphalt is (0.01-0.6):1.

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