Odor-free environment-friendly microcapsule, odor-free environment-friendly asphalt additive and preparation method thereof

Abstract

The invention discloses an odorless environment-friendly microcapsule, an odorless environment-friendly asphalt additive and a preparation method of the odorless environment-friendly microcapsule. The odorless environment-friendly microcapsule comprises a composite shell material and a core material, the composite shell material comprises an inorganic base layer shell / nano tourmaline / polydopamine, and the core material comprises one or more odorless agents; a metal chelate is loaded on the surface of the shell material. The odorless environment-friendly microcapsule disclosed by the invention not only can efficiently and durably reduce the content of irritant gas in asphalt smoke, but also can enable the asphalt to emit pleasant fragrance in a construction process, and provides a brand new idea for environment-friendly application of the asphalt.

Description

Technical Field

[0001] The invention belongs to the field of environmentally friendly asphalt, and specifically relates to an odorless environmentally friendly microcapsule, an odorless environmentally friendly asphalt additive and a preparation method thereof. Background Art

[0002] On the one hand, traditional asphalt pavement meets the traffic requirements of vehicles and pedestrians due to its excellent performance, but on the other hand, it produces a large amount of toxic and harmful asphalt fumes with pungent odors during the mixing and paving process, which brings a series of problems that are contrary to environmental protection, restricts economic development, and threatens human health. Therefore, it is very necessary to carry out relevant research on reducing harmful gas emissions during the construction of asphalt pavement.

[0003] The commonly used method for reducing asphalt smoke emissions is the additive modification method. The additives used in this method are usually highly active flavor compounds. After being added to asphalt, they can not only achieve the purpose of enhancing fragrance and suppressing odor, but also react with volatile and more active components in asphalt to improve its molecular weight and stability, avoid its cracking and volatilization at high temperature, and achieve the purpose of reducing the amount of irritating smoke released by asphalt during construction.

[0004] In order to better mix and react with asphalt, additives need to be added when the asphalt temperature is high. However, the additives used in the additive modification method usually have a low boiling point, which causes some additives to volatilize due to heat before they chemically react with the relevant components in the asphalt, reducing their smoke emission reduction and odor suppression effects. In addition, relevant studies have shown that the compounds generated by the reaction of additives with asphalt-related components have poor storage stability and are prone to decomposition after being stored at high temperatures for a period of time, which causes the smoke emission reduction effect of the prepared asphalt to decrease with the increase in storage time.

[0005] CN111849027A discloses an environmentally friendly odor-free asphalt modifier and its modified asphalt. The modified asphalt is prepared by directly adding some smoke-suppressing compounds with a low boiling point into asphalt and stirring it to form an odor-free environmentally friendly asphalt. However, the odor-free environmentally friendly asphalt prepared by this method has a short-lasting odor-free effect, so it needs to be constructed immediately after preparation and cannot be transported or stored for a long time.

[0006] In summary, the use of additive modification method to prepare odorless and environmentally friendly asphalt usually has the problem of not being able to be stored for a long time, making it difficult to apply on a large scale. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a deodorizing and environmentally friendly microcapsule, a deodorizing and environmentally friendly asphalt additive and a preparation method thereof. The deodorizing and environmentally friendly microcapsule of the present invention can not only effectively and permanently reduce the content of irritating gases in asphalt fume, but also make the asphalt emit a pleasant aroma during the construction process, providing a new idea for the environmentally friendly application of asphalt.

[0008] The first aspect of the present invention provides an odor-free and environmentally friendly microcapsule, which includes a composite shell material and a core material, wherein the composite shell material includes an inorganic base shell / nano-tourmaline / polydopamine, and the core material includes one or more odor-free agents; the surface of the shell material is loaded with a metal chelate.

[0009] Furthermore, the particle size of the odorless and environmentally friendly microcapsules is 1-5 μm.

[0010] Furthermore, the mass ratio of the odorless and environmentally friendly microcapsule composite shell material to the core material is 1:(0.5-2).

[0011] Furthermore, the deodorant is one or more of aldehydes, alcohols, esters, and ketones, and preferably includes aldehydes, alcohols, esters, and ketones at the same time.

[0012] Furthermore, the aldehydes are selected from one or more of aliphatic aldehydes having a carbon number greater than 10 and aromatic aldehydes having a carbon number greater than 7. The aliphatic aldehyde having a carbon number greater than 10 is selected from one or more of 2-methylundecylaldehyde and 10-undecenal; the aromatic aldehyde having a carbon number greater than 7 is selected from one or more of benzaldehyde, cinnamaldehyde, o-methoxy-p-methylbenzaldehyde, 2-methyl-3-(4-isopropylphenyl)propanal, and 2-methyl-3-(3,4-methylenedioxyphenyl)propanal.

[0013] Furthermore, the alcohol is selected from one or more of terpene alcohols with a carbon number greater than 10 and cyclic terpene alcohols with a carbon number greater than 10. The terpene alcohols with a carbon number greater than 10 are selected from one or more of geraniol, linalool, citronellol, ionol, farnesol, myrcene alcohol, lavandulol, and nerolidol; the cyclic terpene alcohols with a carbon number greater than 10 are selected from one or more of menthol, terpineol, isobornyl alcohol, cedarwood alcohol, and santalol.

[0014] Furthermore, the esters are selected from one or more of aromatic esters with carbon atoms greater than 12 and terpene esters with carbon atoms greater than 11. The aromatic esters with carbon atoms greater than 12 are selected from one or more of isoamyl benzoate, benzyl benzoate, isoamyl salicylate, benzyl salicylate, leaf alcohol salicylate, benzyl cinnamate, and phenylethyl cinnamate; the terpene esters with carbon atoms greater than 11 are selected from one or more of geranyl formate, geranyl acetate, geranyl propionate, neryl acetate, linalyl formate, linalyl propionate, lavender acetate, and citronellal butyrate.

[0015] Further, the ketones are selected from one or more of aliphatic ketones with carbon number greater than 3 and cyclic terpene ketones with carbon number greater than 10. The aliphatic ketones with carbon number greater than 3 are selected from one or more of 3-hydroxy-2-butanone, 2,3-butanedione, and 3-pentene-2-one; the cyclic terpene ketones with carbon number greater than 10 are selected from one or more of damascenone, ionone, irone, menthone, and carvone.

[0016] Furthermore, the composite shell material comprises inorganic base shell / nano-tourmaline / polydopamine, wherein the mass ratio of the inorganic base shell to the nano-tourmaline is (1-5):1, and the mass ratio of the inorganic base shell to the polydopamine is 1:(0.1-1).

[0017] Furthermore, the material of the inorganic base shell is selected from one of silicon dioxide and titanium dioxide, preferably silicon dioxide.

[0018] Furthermore, the surface of the composite shell material is loaded with a metal chelate, wherein the metal is preferably copper.

[0019] Furthermore, the surface of the composite shell material is loaded with metal chelates, and the metal loading accounts for 0.1wt%-10wt% of the total mass of the odorless and environmentally friendly microcapsules.

[0020] The second aspect of the present invention provides a method for preparing odorless and environmentally friendly microcapsules, comprising the following steps:

[0021] S1: mixing nano-tourmaline, a surfactant and a solvent, modifying the mixture under stirring, washing the mixture after the modification, and freeze-drying the mixture to obtain modified nano-tourmaline;

[0022] S2: stirring and mixing one or more deodorizing agents to obtain a core material mixed liquid;

[0023] S3: adding a solvent and the modified nano-tourmaline obtained in step S1 to the core material mixed solution obtained in step S2, and stirring and mixing;

[0024] S4: adding an inorganic base shell precursor to the reaction system of step S3, stirring and mixing, and obtaining a Pickering emulsion;

[0025] S5: adjusting the pH value of the Pickering emulsion obtained in step S4 to 3-6, continuing stirring, and then aging, filtering, and freeze-drying to obtain a odorless and environmentally friendly microcapsule matrix;

[0026] S6: dispersing the odorless and environmentally friendly microcapsule matrix obtained in step S5 in a buffer solution, adding dopamine hydrochloride, treating under stirring, and then filtering, washing, and freeze-drying;

[0027] S7: dispersing the solid powder obtained after freeze-drying in step S6 in a metal ion salt-formamide solution, treating under stirring, and after the reaction is completed, filtering, washing, and freeze-drying to obtain odorless and environmentally friendly microcapsules.

[0028] Furthermore, in step S1, the surfactant is a cationic surfactant, preferably at least one of hexadecyltrimethylammonium bromide, dodecyldimethylbenzylammonium chloride, and octadecyltrimethylammonium chloride.

[0029] Furthermore, in step S1, the solvent is an aprotic solvent with a boiling point > 100°C, preferably at least one of formamide, N,N-dimethylformamide, dimethylacetamide, and dimethylphosphoramide, and more preferably formamide.

[0030] Furthermore, in step S1, the mass ratio of the nano-tourmaline to the surfactant is (1-10):1, and the mass ratio of the solvent to the surfactant is (10-40):1.

[0031] Furthermore, in step S1, the stirring speed is 400-600 rpm; the modification temperature is 100-190° C., and the modification time is 4-8 hours.

[0032] Furthermore, in step S1, the freeze-drying conditions are: vacuum drying at a temperature of -40°C to -20°C for 4-8 hours.

[0033] Furthermore, in step S2, the stirring speed is 400-600 rpm, the stirring temperature is 30-70° C., and the stirring time is 3-10 minutes.

[0034] Furthermore, in step S3, the solvent is an aprotic solvent with a boiling point > 100°C, preferably at least one of formamide, N,N-dimethylformamide, dimethylacetamide, and dimethylphosphoramide, and more preferably N,N-dimethylformamide.

[0035] Furthermore, in step S3, the mass ratio of the core material mixture to the modified nano-tourmaline is (1-10):1, and the mass ratio of the solvent to the modified nano-tourmaline is (10-40):1.

[0036] Furthermore, in step S3, the stirring speed is 400-600 rpm, the stirring temperature is 30-60° C., and the stirring time is 4-6 hours.

[0037] Furthermore, in step S4, the inorganic base shell precursor is one of a silicate compound and a titanate compound, preferably a silicate compound.

[0038] Furthermore, the silicate compound is preferably one or more of methyl silicate, ethyl orthosilicate, tetraethyl orthosilicate, and butyl orthosilicate, and is more preferably tetraethyl orthosilicate.

[0039] Furthermore, in step S4, the mass ratio of the core material mixture to the inorganic base shell precursor is (0.5-2): 1. The stirring speed is 400-600 rpm, the stirring temperature is 30-60° C., and the stirring time is 4-6 hours.

[0040] Furthermore, in step S5, the pH can be adjusted by using dilute acid, such as dilute hydrochloric acid. The stirring speed is 400-600 rpm, the stirring temperature is 30-60° C., and the stirring time is 4-6 hours.

[0041] Furthermore, in step S5, the aging condition is: standing at 40-60°C for 12-30 hours. The freeze-drying condition is: vacuum drying at a temperature of -40--20°C for 4-8 hours.

[0042] Furthermore, in step S6, the buffer is one or more of phosphate buffer, carbonate buffer, and Tris buffer, preferably Tris buffer.

[0043] Furthermore, in step S6, the pH value of the buffer solution is preferably 8-10.

[0044] Furthermore, in step S6, the mass ratio of the buffer solution to the odorless and environmentally friendly microcapsule matrix obtained in step S5 is (10-100):1.

[0045] Furthermore, in step S6, after adding dopamine hydrochloride, the mass concentration of dopamine in the reaction system is 2-10 mg / mL.

[0046] Furthermore, in step S6, the stirring speed is 100-300 rpm, the stirring temperature is 20-40° C., and the stirring time is 12-24 hours.

[0047] Furthermore, in step S6, the freeze-drying conditions are: vacuum drying at a temperature of -40°C to -20°C for 4-8 hours.

[0048] Furthermore, in step S7, the solid powder obtained after freeze-drying in step S6 is dispersed in a metal ion salt-formamide solution, and ultrasonic dispersion can be used.

[0049] Furthermore, in step S7, the metal ion salt is preferably a copper ion salt, and more preferably anhydrous copper sulfate.

[0050] Furthermore, in step S7, in the metal ion salt-formamide solution, the mass ratio of the metal ion salt to formamide is (0.5-1.5):1.

[0051] Furthermore, in step S7, the mass ratio of the metal ion salt-formamide solution to the solid powder obtained after freeze-drying in step S7 is (5-20):1.

[0052] Furthermore, in step S7, the stirring speed is 200-450 rpm, the treatment temperature is 100-190° C., and the treatment time is 2-5 hours.

[0053] Furthermore, in step S7, the freeze-drying conditions are: vacuum drying at -40°C to -20°C for 4-8h.

[0054] The third aspect of the present invention provides a odorless and environmentally friendly asphalt additive, comprising the following components by weight:

[0055] 1-10 parts of the above-mentioned odorless and environmentally friendly microcapsules;

[0056] Dispersant, 1-10 parts.

[0057] Furthermore, the dispersant is one or more of dodecyl dimethyl betaine and 1-hydroxyethyl-carboxymethyl-alkyl imidazoline.

[0058] Furthermore, the dispersant and the odorless and environmentally friendly microcapsules are stirred and mixed at a rotation speed of 200-400 rpm at room temperature for 1-3 hours to obtain the odorless and environmentally friendly asphalt additive.

[0059] A fourth aspect of the present invention provides a odorless and environmentally friendly asphalt, comprising the following components by weight:

[0060] Base asphalt, 100-300 parts;

[0061] The above-mentioned odorless and environmentally friendly asphalt additive, 1-50 parts.

[0062] Furthermore, the base asphalt is heated to 133-153° C., the odorless and environment-friendly asphalt additive is added at a rotation speed of 200-400 rpm, and stirred for 2-4 hours to obtain the odorless and environment-friendly asphalt.

[0063] Compared with the prior art, the present invention has the following advantages:

[0064] (1) The odorless and environmentally friendly microcapsules of the present invention, whose composite shell material includes an inorganic base shell / nanotourmaline / polydopamine, have three functions. First, during the preparation process, nanotourmaline serves as a template for the synthesis of microcapsules and can maintain the stability of the core material mixed droplets. Second, during the metal ion modification of the microcapsule composite shell material, a large amount of metal ions are adsorbed onto the microcapsule surface by means of the negative ion field released by nanotourmaline under high temperature conditions, effectively increasing the metal ion loading capacity of the microcapsule shell material and further improving the smoke suppression ability of the sustained-release modified microcapsules. The third function is that during the asphalt mixing process, the nanotourmaline contained in the sustained-release modified microcapsule shell material will release a negative ion field under the action of high temperature, further attracting the compounds released by the asphalt under the action of high temperature to the surrounding of the sustained-release modified microcapsules. While increasing the difficulty of these compounds to volatilize, the metal ions on the microcapsule surface and the smoke suppression active components of the microcapsule sustained release can react with more of the above compounds, thereby effectively reducing the impact of the irritating gas released by the asphalt pavement on the human body.

[0065] (2) The odorless and environmentally friendly asphalt described in the present invention contains odorless and environmentally friendly microcapsules, and the surface of its composite shell material is modified with a layer of chelated metal ions. This layer of chelated metal ions has empty orbitals. After the odorless and environmentally friendly microcapsules enter the asphalt system, the chelated metal ions can directly accept the unshared electrons of some more active sulfur-containing and nitrogen-containing pollutants in the asphalt and form coordination bonds, thereby stably fixing the above-mentioned compounds on the surface of the odorless and environmentally friendly microcapsules, avoiding their high-temperature volatilization, and further quickly reducing the content of irritating gases in the asphalt flue gas.

[0066] (3) The odorless and environmentally friendly asphalt of the present invention has odorless and environmentally friendly microcapsules added to it, and the odorless active components with lower boiling points are coated in a composite shell material. These active components can be slowly released from the microcapsules during the storage and construction of asphalt, thereby avoiding the problems of decreased emission reduction effect and short duration caused by the active components volatilizing at high temperatures and not reacting with related components in asphalt. In addition, the odorless and environmentally friendly asphalt of the present invention has odorless and environmentally friendly microcapsules added to it, which are smaller in size, and its outer layer is a polydopamine film that can generate a force with the polar molecules in asphalt and has good compatibility with asphalt. Therefore, after it is added to asphalt, it can effectively prevent the road performance of asphalt from being affected.

[0067] (4) The odorless and environmentally friendly asphalt of the present invention has added odorless and environmentally friendly microcapsules with a fragrant aroma, and the type of aroma can be adjusted according to requirements. After being added to asphalt, it can play a role in suppressing odor during asphalt construction, further reducing the sensory impact of asphalt smoke on construction workers and residents around the construction road surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 This is a scanning electron microscope photograph of the odorless and environmentally friendly microcapsules obtained in Example 1. DETAILED DESCRIPTION

[0069] To further illustrate the technical solution of the present invention, the present invention will be clearly and detailed described below in conjunction with embodiments.

[0070] The odorless and environmentally friendly microcapsules of the present invention are tested for morphology by scanning electron microscopy, and the acceleration voltage used is 20 kV. Since the wall material of the microcapsule is not conductive, the sample needs to be treated with gold spraying before the test.

[0071] The odorless and environmentally friendly microcapsules of the present invention are tested for surface elements by an X-ray spectrometer to confirm that the metal ions are successfully modified on the surface of the microcapsules.

[0072] The sulfide in the odorless and environmentally friendly asphalt flue gas of the present invention is tested by a gas chromatograph according to the national standard GBT14678-1993 Air quality hydrogen sulfide, methyl mercaptan, methyl sulfide and dimethyl disulfide determination gas chromatography method.

[0073] The base asphalt used in the following examples and comparative examples is Sinopec Donghai brand No. 70 Grade A asphalt.

[0074] Example 1

[0075] S1: Nano-tourmaline with a particle size of 40 nm, octadecyltrimethylammonium chloride and formamide are stirred at a mass ratio of 1:1:20 at 180°C and 400 rpm for 5 hours, then washed with ethanol for multiple times, and vacuum dried at -30°C for 5 hours to obtain modified nano-tourmaline for later use;

[0076] S2: Mix 2-methylundecanal, cinnamaldehyde, linalool, santalol, salicylic acid leaf alcohol ester, geranyl acetate, 3-penten-2-one, damascenone and other substances, and stir at 50° C. and 400 rpm for 10 minutes to obtain a core material mixture;

[0077] S3: Add the modified nano-tourmaline and N,N-dimethylformamide prepared in step S1 to the reaction system of step S2, wherein the mass ratio of the core material mixture, the modified nano-tourmaline and N,N-dimethylformamide is 2:1:20, and continue to stir at 400 rpm at 50°C for 5 hours;

[0078] S4: adding tetraethyl orthosilicate to the reaction system of step S3, wherein the mass ratio of the core material mixture to tetraethyl orthosilicate is 1:1, and continuing to stir at 400 rpm at 50° C. for 5 hours to obtain a Pickering emulsion;

[0079] S5: Use a peristaltic pump to slowly drop 10 wt % dilute hydrochloric acid into the reaction system of step S4 until the pH of the reaction system is 4, continue stirring at 400 rpm at 50°C for 5 hours, then stop stirring, keep the temperature unchanged and age for 24 hours, then filter and wash the solid powder in the reaction system, and vacuum dry it at -30°C for 5 hours to obtain a odorless and environmentally friendly microcapsule matrix;

[0080] S6: adding the odorless and environmentally friendly microcapsule matrix prepared in step S5 into a Tris buffer solution with a pH value of 8.5, wherein the mass ratio of the Tris buffer solution to the odorless and environmentally friendly microcapsule matrix is ​​40:1, and then adding dopamine hydrochloride to make the concentration of dopamine in the reaction system 3 mg / mL, stirring at 200 rpm for 12 hours at 25°C, then stopping stirring, filtering and washing the bottom solid powder, and vacuum drying at a temperature of -30°C for 5 hours;

[0081] S7: Ultrasonic dispersion of the solid powder obtained in step S6 in a 50wt% anhydrous copper sulfate-formamide solution, the mass ratio of the solid powder to the anhydrous copper sulfate-formamide solution being 1:10, stirring and reacting at 400 rpm and 140°C for 2 hours, after the stirring is completed, filtering, washing, and freeze-drying the solid powder to obtain a odorless and environmentally friendly microcapsule, the electron microscope image of which is shown in FIG. Figure 1 .

[0082] The odorless and environmentally friendly microcapsules prepared in step S7 and dodecyl dimethyl betaine are stirred and mixed at a rotation speed of 300 rpm at room temperature for 3 hours to prepare an odorless and environmentally friendly asphalt additive. The mass ratio of the odorless and environmentally friendly microcapsules to dodecyl dimethyl betaine is 1:1.

[0083] Heat 100 parts of base asphalt to 143°C, add 10 parts of the above-mentioned odorless and environmentally friendly asphalt additive at a rotation speed of 400 rpm, and stir for 4 hours to obtain the odorless and environmentally friendly asphalt.

[0084] Example 2

[0085] Except that the mass ratio of tetraethyl orthosilicate to the core material mixed liquid in step S4 is 1:0.5, the rest is the same as that in Example 1.

[0086] Example 3

[0087] Except that when preparing the odorless and environmentally friendly asphalt additive, the dispersant is 1-hydroxyethyl-carboxymethyl-alkyl imidazoline, the rest is the same as Example 1.

[0088] Example 4

[0089] Except that in step S2, the core material mixture is mixed by mass of 10-11 enal, 2-methyl-3-(4-isopropylphenyl) propionaldehyde, geraniol, menthol, benzyl salicylate, lavandin acetate, 2,3-butanedione, ionone, etc., the rest is the same as Example 1.

[0090] Example 5

[0091] The method is the same as that in Example 1 except that the mass ratio of the odorless and environmentally friendly microcapsules to dodecyl dimethyl betaine is 3:1 when preparing the odorless and environmentally friendly asphalt additive.

[0092] Example 6

[0093] Except that when preparing the odorless and environmentally friendly asphalt, the amount of base asphalt used is 200 parts, the rest is the same as Example 1.

[0094] Example 7

[0095] Except that the mass ratio of the core material mixed solution, the modified nano-tourmaline and the N,N-dimethylformamide in step S3 is 3:1:20, the rest is the same as that in Example 1.

[0096] Comparative Example 1

[0097] S1: Mix 2-methylundecanal, cinnamaldehyde, linalool, santalol, salicylic acid leaf alcohol ester, geranyl acetate, methyl nonyl ketone, menthone and the like, and stir at 400 rpm for 10 minutes at 50°C to obtain a deodorized mixed solution.

[0098] The odor-free mixed solution prepared in step S1 and dodecyl dimethyl betaine are stirred and mixed at a rotation speed of 300 rpm at room temperature for 3 hours, and the mass ratio of the mixed solution to dodecyl dimethyl betaine is 1:1.

[0099] Heat 100 parts of base asphalt to 143°C, add 10 parts of the mixed solution prepared above at a rotation speed of 400 rpm, and stir for 4 hours to obtain odorless and environmentally friendly asphalt.

[0100] Comparative Example 2

[0101] S1: Nano-tourmaline with a particle size of 40 nm, octadecyltrimethylammonium chloride and formamide are stirred at a mass ratio of 1:1:20 at 180°C and 400 rpm for 5 hours, then washed with ethanol for multiple times, and vacuum dried at -30°C for 5 hours to obtain modified nano-tourmaline for later use;

[0102] S2: Mix 2-methylundecanal, cinnamaldehyde, linalool, santalol, leaf salicylate, geranyl acetate, methyl nonyl ketone, menthone and the like, and stir at 50° C. and 400 rpm for 10 minutes to obtain a core material mixture;

[0103] S3: Add the modified nano-tourmaline and N,N-dimethylformamide prepared in step S1 to the reaction system of step S2, wherein the mass ratio of the core material mixture, the modified nano-tourmaline and N,N-dimethylformamide is 2:1:20, and continue to stir at 400 rpm at 50°C for 5 hours;

[0104] S4: adding tetraethyl orthosilicate to the reaction system of step S3, wherein the mass ratio of the core material mixture to tetraethyl orthosilicate is 1:1, and continuing to stir at 400 rpm at 50° C. for 5 hours to obtain a Pickering emulsion;

[0105] S5: Use a peristaltic pump to slowly drop 10 wt % dilute hydrochloric acid into the reaction system of step S4 until the pH of the reaction system is 4, continue stirring at 400 rpm at 50°C for 5 hours, then stop stirring, keep the temperature unchanged and age for 24 hours, then filter and wash the solid powder in the reaction system, and vacuum dry it at -30°C for 5 hours to obtain a odorless and environmentally friendly microcapsule matrix;

[0106] S6: Add the odorless and environmentally friendly microcapsule matrix prepared in step S5 into a Tris buffer solution with a pH value of 8.5, wherein the mass ratio of the Tris buffer solution to the odorless and environmentally friendly microcapsule matrix is ​​40:1, and then add dopamine hydrochloride to make the concentration of dopamine in the reaction system 3 mg / mL. Stir at 200 rpm at 25°C for 12 hours and then stop stirring. Filter and wash the solid powder on the bottom layer, and vacuum dry it at -30°C for 5 hours.

[0107] The solid powder obtained in step S6 and dodecyl dimethyl betaine are stirred and mixed at a rotation speed of 300 rpm at room temperature for 3 hours to obtain a odorless and environmentally friendly asphalt additive, and the mass ratio of the odorless and environmentally friendly microcapsules to dodecyl dimethyl betaine is 1:1.

[0108] Heat 100 parts of base asphalt to 143°C, add 10 parts of the above-mentioned odorless and environmentally friendly asphalt additive at a rotation speed of 400 rpm, and stir for 4 hours to obtain the odorless and environmentally friendly asphalt.

[0109] Comparative Example 3

[0110] The preparation of odorless and environmentally friendly microcapsules is the same as that in Example 1, the only difference is that when preparing odorless and environmentally friendly asphalt, 100 parts of base asphalt are directly heated to 143°C, 5 parts of odorless and environmentally friendly microcapsules are added at a rotation speed of 400 rpm, and the odorless and environmentally friendly asphalt is obtained by stirring for 4 hours.

[0111] Comparative Example 4

[0112] S1: 2-methylundecanal, cinnamaldehyde, linalool, santalol, salicylic acid leaf alcohol ester, geranyl acetate, 3-penten-2-one, damascenone and the like were mixed, and stirred at 400 rpm for 10 minutes at 50°C to obtain a core material mixture;

[0113] S2: Add octadecyltrimethylammonium chloride and N,N-dimethylformamide to the reaction system of step S1, the mass ratio of the core material mixture, hexadecyltrimethylammonium bromide and N,N-dimethylformamide is 2:1:20, and continue to stir at 400 rpm at 50°C for 5 hours;

[0114] S3: adding tetraethyl orthosilicate to the reaction system of step S2, with the mass ratio of the core material mixture to tetraethyl orthosilicate being 1:1, and continuing to stir at 400 rpm at 50° C. for 5 hours to obtain a Pickering emulsion;

[0115] S4: Use a peristaltic pump to slowly add 10 wt% dilute hydrochloric acid to the reaction system of step S3 until the pH of the reaction system is 4, continue stirring at 400 rpm at 50°C for 5 hours, then stop stirring, keep the temperature unchanged and age for 24 hours, then filter and wash the solid powder in the reaction system, and vacuum dry it at -30°C for 5 hours to obtain a odorless and environmentally friendly microcapsule matrix;

[0116] S5: adding the odorless and environmentally friendly microcapsule matrix prepared in step S4 into a Tris buffer solution with a pH value of 8.5, wherein the mass ratio of the Tris buffer solution to the odorless and environmentally friendly microcapsule matrix is ​​40:1, and then adding dopamine hydrochloride to make the concentration of dopamine in the reaction system 3 mg / mL, stirring at 200 rpm for 12 hours at 25°C, then stopping stirring, filtering and washing the bottom solid powder, and vacuum drying at a temperature of -30°C for 5 hours;

[0117] S6: Ultrasonic dispersion of the solid powder obtained in step S5 in a 50wt% anhydrous copper sulfate-formamide solution, wherein the mass ratio of the solid powder to the anhydrous copper sulfate-formamide solution is 1:10, and stirring the mixture at 400 rpm and 140°C for 2 hours. After stirring, the solid powder is filtered, washed, and freeze-dried to obtain odorless and environmentally friendly microcapsules.

[0118] The odorless and environmentally friendly microcapsules prepared in step S6 and dodecyl dimethyl betaine are stirred and mixed at a rotation speed of 300 rpm at room temperature for 3 hours to prepare an odorless and environmentally friendly asphalt additive. The mass ratio of the odorless and environmentally friendly microcapsules to dodecyl dimethyl betaine is 1:1.

[0119] Heat 100 parts of base asphalt to 143°C, add 10 parts of the above-mentioned odorless and environmentally friendly asphalt additive at a rotation speed of 400 rpm, and stir for 4 hours to obtain the odorless and environmentally friendly asphalt.

[0120] Test Case

[0121] Sulfide is the main reason for the pungent smell of asphalt fume. The odorless and environmentally friendly asphalt prepared in Examples 1-7 and Comparative Examples 1-4 was stored at 143°C for 0 days, 7 days and 30 days. Then, an equal mass of the stored asphalt was transferred to a closed container and the flue gas was enriched at a temperature of 163°C and a stirring speed of 300 rpm for 4 hours. After the enrichment, the gas in the closed container was aspirated and tested using gas chromatography. The data obtained are shown in Table 1 below.

[0122] Table 1 Sulfide content test

[0123]

[0124] It should be emphasized that the above-mentioned contents are only specific embodiments of the present invention, and it cannot be determined that the present invention is limited to the above description in the specific implementation process. For those skilled in the art of the present invention, any simple deduction and improvement made without departing from the ideas and principles of the present invention shall be deemed to be within the scope of protection of the present invention.

Claims

1. A odorless and environmentally friendly microcapsule, characterized by: The deodorizing and environmentally friendly microcapsule comprises a composite shell material and a core material, wherein the composite shell material comprises an inorganic base shell / nano-tourmaline / polydopamine, and the core material comprises one or more deodorizing agents; and the surface of the shell material is loaded with a metal chelate.

2. The odorless and environmentally friendly microcapsule according to claim 1, characterized in that: The particle size of the odorless and environmentally friendly microcapsules is 1-5 μm.

3. The odorless and environmentally friendly microcapsule according to claim 1, characterized in that: The mass ratio of the odorless and environmentally friendly microcapsule composite shell material to the core material is 1:(0.5-2).

4. The odorless and environmentally friendly microcapsule according to claim 1, characterized in that: The deodorant is one or more of aldehydes, alcohols, esters, and ketones, preferably including aldehydes, alcohols, esters, and ketones at the same time; Preferably, the aldehydes are selected from one or more of aliphatic aldehydes having a carbon number greater than 10 and aromatic aldehydes having a carbon number greater than 7; the aliphatic aldehydes having a carbon number greater than 10 are selected from one or more of 2-methylundecylaldehyde and 10-undecenal; the aromatic aldehydes having a carbon number greater than 7 are selected from one or more of benzaldehyde, cinnamaldehyde, o-methoxy-p-methylbenzaldehyde, 2-methyl-3-(4-isopropylphenyl)propanal, and 2-methyl-3-(3,4-methylenedioxyphenyl)propanal; Preferably, the alcohol is selected from one or more of terpene alcohols with a carbon number greater than 10 and cyclic terpene alcohols with a carbon number greater than 10; the terpene alcohols with a carbon number greater than 10 are selected from one or more of geraniol, linalool, citronellol, ionol, farnesol, myrcenol, lavandulol, and nerolidol; the cyclic terpene alcohols with a carbon number greater than 10 are selected from one or more of menthol, terpineol, isobornyl alcohol, cedarwood alcohol, and santalol; Preferably, the esters are selected from one or more of aromatic esters having a carbon number greater than 12 and terpene esters having a carbon number greater than 11; the aromatic esters having a carbon number greater than 12 are selected from one or more of isoamyl benzoate, benzyl benzoate, isoamyl salicylate, benzyl salicylate, leaf alcohol salicylate, benzyl cinnamate, and phenylethyl cinnamate; the terpene esters having a carbon number greater than 11 are selected from one or more of geranyl formate, geranyl acetate, geranyl propionate, neryl acetate, linalyl formate, linalyl propionate, lavender acetate, and citronellal butyrate; Preferably, the ketones are selected from one or more of aliphatic ketones having a carbon number greater than 3 and cyclic terpene ketones having a carbon number greater than 10; the aliphatic ketones having a carbon number greater than 3 are selected from one or more of 3-hydroxy-2-butanone, 2,3-butanedione, and 3-pentene-2-one; the cyclic terpene ketones having a carbon number greater than 10 are selected from one or more of damascenone, ionone, irone, menthone, and carvone.

5. The odorless and environmentally friendly microcapsule according to claim 1, characterized in that: The composite shell material comprises inorganic base shell / nano-tourmaline / polydopamine, wherein the mass ratio of the inorganic base shell to the nano-tourmaline is (1-5):1, and the mass ratio of the inorganic base shell to the polydopamine is 1:(0.1-1).

6. The odorless and environmentally friendly microcapsule according to claim 1, characterized in that: The material of the inorganic base shell is selected from silicon dioxide and titanium dioxide, preferably silicon dioxide.

7. The odorless and environmentally friendly microcapsule according to claim 1, characterized in that: The surface of the composite shell material is loaded with a metal chelate, wherein the metal is preferably copper; the metal loading accounts for 0.1wt%-10wt% of the total mass of the odorless and environmentally friendly microcapsule.

8. A method for preparing odorless and environmentally friendly microcapsules, characterized in that: The following steps are involved: S1: mixing nano-tourmaline, a surfactant and a solvent, modifying the mixture under stirring, washing the mixture after the modification, and freeze-drying the mixture to obtain modified nano-tourmaline; S2: stirring and mixing one or more deodorizing agents to obtain a core material mixed liquid; S3: adding a solvent and the modified nano-tourmaline obtained in step S1 to the core material mixed solution obtained in step S2, and stirring and mixing; S4: adding an inorganic base shell precursor to the reaction system of step S3, stirring and mixing, and obtaining a Pickering emulsion; S5: adjusting the pH value of the Pickering emulsion obtained in step S4 to 3-6, continuing stirring, and then aging, filtering, and freeze-drying to obtain a odorless and environmentally friendly microcapsule matrix; S6: dispersing the odorless and environmentally friendly microcapsule matrix obtained in step S5 in a buffer solution, adding dopamine hydrochloride, treating under stirring, and then filtering, washing, and freeze-drying; S7: dispersing the solid powder obtained after freeze-drying in step S6 in a metal ion salt-formamide solution, treating under stirring, and after the reaction is completed, filtering, washing, and freeze-drying to obtain odorless and environmentally friendly microcapsules.

9. The preparation method according to claim 8, characterized in that: In step S1, the surfactant is a cationic surfactant, preferably at least one of hexadecyltrimethylammonium bromide, dodecyldimethylbenzylammonium chloride, and octadecyltrimethylammonium chloride; the solvent is an aprotic solvent with a boiling point > 100°C, preferably at least one of formamide, N,N-dimethylformamide, dimethylacetamide, and dimethylphosphoramide, and more preferably formamide; And / or, in step S1, the mass ratio of the nano-tourmaline to the surfactant is (1-10):1, and the mass ratio of the solvent to the surfactant is (10-40):

1.

10. The preparation method according to claim 8, characterized in that: In step S1, the stirring speed is 400-600 rpm; the modification temperature is 100-190° C., and the modification time is 4-8 hours; And / or, in step S2, the stirring speed is 400-600 rpm, the stirring temperature is 30-70° C., and the stirring time is 3-10 minutes; And / or, in step S3, the stirring speed is 400-600 rpm, the stirring temperature is 30-60° C., and the stirring time is 4-6 hours; And / or, in step S4, the stirring speed is 400-600 rpm, the stirring temperature is 30-60° C., and the stirring time is 4-6 hours; And / or, in step S5, the stirring speed is 400-600 rpm, the stirring temperature is 30-60° C., and the stirring time is 4-6 hours; And / or, in step S6, the stirring speed is 100-300 rpm, the stirring temperature is 20-40° C., and the stirring time is 12-24 hours; And / or, in step S7, the stirring speed is 200-450 rpm, the treatment temperature is 100-190° C., and the treatment time is 2-5 hours.

11. The preparation method according to claim 8, characterized in that: In step S3, the solvent is an aprotic solvent with a boiling point > 100° C., preferably at least one of formamide, N,N-dimethylformamide, dimethylacetamide, and dimethylphosphoramide, and more preferably N,N-dimethylformamide; And / or, in step S3, the mass ratio of the core material mixture to the modified nano-tourmaline is (1-10):1, and the mass ratio of the solvent to the modified nano-tourmaline is (10-40):

1.

12. The preparation method according to claim 8, characterized in that: In step S4, the inorganic base shell precursor is one of a silicate compound and a titanate compound, preferably a silicate compound; And / or, the silicate compound is preferably one or more of methyl silicate, ethyl orthosilicate, tetraethyl orthosilicate, and butyl orthosilicate, and is further preferably tetraethyl orthosilicate; And / or, the mass ratio of the core material mixture to the inorganic base shell precursor is (0.5-2):

1.

13. The preparation method according to claim 8, characterized in that: In step S6, the buffer solution is one or more of a phosphate buffer solution, a carbonate buffer solution, and a tris(hydroxymethyl)aminomethane hydrochloride buffer solution, preferably a tris(hydroxymethyl)aminomethane hydrochloride buffer solution; the pH value of the buffer solution is preferably 8-10; And / or, the mass ratio of the buffer solution to the odorless and environmentally friendly microcapsule matrix obtained in step S5 is (10-100):

1.

14. The preparation method according to claim 8, characterized in that: In step S6, after adding dopamine hydrochloride, the mass concentration of dopamine in the reaction system is 2-10 mg / mL.

15. The preparation method according to claim 8, characterized in that: In step S7, the metal ion salt is preferably a copper ion salt, and more preferably anhydrous copper sulfate; And / or, in the metal ion salt-formamide solution, the mass ratio of the metal ion salt to formamide is (0.5-1.5):

1.

16. A clean and environmentally friendly asphalt additive, characterized by: The following components are included by weight: 1-10 parts of the odorless and environmentally friendly microcapsules described in any one of claims 1-7 or the odorless and environmentally friendly microcapsules prepared by the method described in any one of claims 8-15; Dispersant, 1-10 parts.

17. The odorless and environmentally friendly asphalt additive according to claim 16, characterized in that: The dispersant is one or more of dodecyl dimethyl betaine and 1-hydroxyethyl-carboxymethyl-alkyl imidazoline.

18. A odorless and environmentally friendly asphalt comprising the following components by weight: Base asphalt, 100-300 parts; 1-50 parts of the odorless and environmentally friendly asphalt additive according to any one of claims 16-17.

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