阅读说明：本技术 一种合成沥青的制备方法及产品 (Preparation method of synthetic asphalt and product ) 是由 董志军 孙行恒 李轩科 田永胜 袁观明 李保六 郭建光 柯昌美 于 2021-08-02 设计创作，主要内容包括：本发明公开了一种合成沥青的制备方法及产品。通过将芳烃化合物、浓盐酸、冰醋酸、多聚甲醛和催化剂混合后进行Blanc氯甲基化反应,制备氯甲基化产物；利用制得的氯甲基化产物进行聚合反应,制备合成沥青。本发明所提供的方法,反应温度低,反应中所加物料腐蚀性较弱,在常压下即可反应,不涉及到高压,对体系的腐蚀以及高压造成的安全隐患大幅降低,反应条件温和,操作简单,能耗低；同时,本发明所用试剂及原料价格低廉,成本低,所涉及的反应转化率高,收率高。(The invention discloses a preparation method of synthetic asphalt and a product. Aromatic hydrocarbon compounds, concentrated hydrochloric acid, glacial acetic acid, paraformaldehyde and a catalyst are mixed and then subjected to Blanc chloromethylation reaction to prepare chloromethylation products; and carrying out polymerization reaction on the prepared chloromethylation product to prepare the synthetic asphalt. The method provided by the invention has the advantages that the reaction temperature is low, the corrosivity of the materials added in the reaction is weak, the reaction can be carried out under normal pressure, high pressure is not involved, the corrosion to a system and potential safety hazards caused by high pressure are greatly reduced, the reaction condition is mild, the operation is simple, and the energy consumption is low; meanwhile, the reagents and raw materials used in the method are low in price and low in cost, and the related reaction conversion rate and yield are high.)

1. The preparation method of the synthetic asphalt is characterized by comprising the following specific steps:

mixing an aromatic hydrocarbon compound, concentrated hydrochloric acid, glacial acetic acid, paraformaldehyde and a catalyst, and then carrying out a Blanc chloromethylation reaction to prepare a chloromethylation product; and carrying out polymerization reaction on the prepared chloromethylation product to prepare the synthetic asphalt.

2. The method of claim 1, wherein the aromatic hydrocarbon compound is one or more of naphthalene, anthracene, and anthracene oil.

3. The method of claim 1, wherein the catalyst is one or more of zinc chloride, concentrated sulfuric acid, and thionyl chloride.

4. The method of claim 1, wherein the molar ratio of the aromatic hydrocarbon compound to the concentrated hydrochloric acid to the glacial acetic acid to the paraformaldehyde is 1 (3-1) to (2-1).

5. The method for preparing the synthetic asphalt according to claim 1, wherein the reaction temperature of the aromatic hydrocarbon compound, the concentrated hydrochloric acid, the glacial acetic acid, the paraformaldehyde and the catalyst after mixing is 40-100 ℃ and the reaction time is 3-12 h.

6. The method for preparing synthetic asphalt according to claim 1, wherein the chloromethylation product is prepared by the following steps: mixing an aromatic hydrocarbon compound, concentrated hydrochloric acid, glacial acetic acid, paraformaldehyde and a catalyst, reacting, extracting by using dichloromethane after the reaction is finished, separating a water phase and an organic phase, washing with a 10% potassium carbonate solution until the solution is neutral, then washing with water, and drying the washed organic phase to obtain a chloromethylation product.

7. The process for the preparation of synthetic asphalt according to claim 1, wherein the polymerization conditions are: the reaction is carried out for 3-12h under the conditions that the temperature is 200-400 ℃ and the stirring speed is 200-800 r/min, and the whole reaction is carried out in an inert atmosphere.

8. The method for preparing the synthetic asphalt according to claim 1, wherein the polymerization reaction is followed by a step of impurity removal, and the impurity removal method is an extraction method.

9. The preparation method of the synthetic asphalt according to claim 8, wherein an extractant of the extraction method is one or more of a mixed solution of n-hexane, cyclohexane and n-heptane, and the extraction temperature is 50-100 ℃.

10. A synthetic asphalt produced by the method for producing synthetic asphalt according to any one of 1 to 9.

Technical Field

The invention relates to the field of synthetic asphalt, in particular to a preparation method of synthetic asphalt and a product.

Background

Carbon fiber is an excellent light material, has excellent mechanical properties and conductivity, and is widely applied to military, aircraft and aerospace industries. However, the high cost of carbon fibers greatly limits their large-scale use. In recent years, in order to reduce carbon dioxide emissions and improve the average fuel efficiency of commercial vehicles, automobile manufacturers have moved their attention to carbon fibers as a replacement for conventional alloy materials. Compared with the traditional alloy material, the carbon fiber has unique advantages, can meet the requirement of mechanical property, and can greatly reduce the weight of the commercial vehicle. Pitch-based carbon fibers are fully qualified to replace traditional alloy materials in terms of mechanical properties. However, the high cost of carbon fibers is a big problem. To balance the production cost and mechanical properties of carbon fibers and meet the enormous demands of the automotive industry, researchers consider isotropic pitch-based carbon fibers to be the best candidate material. Therefore, how to obtain isotropic pitch-based carbon fibers with excellent mechanical properties and low production cost has been a target of material research.

Since the end of the last century, many effective methods have been developed at home and abroad for the synthesis of asphalt. The research shows that the structure contains more short alkyl and naphthenic structures, so that the structure has more excellent performance. The asphalt is synthesized by adopting the pure aromatic compound for catalytic modification, so that the problem of raw material impurities can be effectively avoided, the reaction process is effectively controlled, long-chain aromatic hydrocarbon molecules with uniform molecular weight distribution and high molecular flatness can be obtained, and the characteristic endows the synthesized asphalt with extremely high rheological property.

The synthetic Pitch is prepared mainly by direct thermal polycondensation (Barr J B, Chwasiak S, et al. high Module Carbon Fibers from Pitch Precursor [ C)]appl.Polym.Symp.1976,29: 161-173)), which breaks C-H bonds by high temperature and then effects condensation under C-C bond formation, but which involves excessive condensation reactions, produces some macromolecules and leads to high softening points, and thus pyrolysis reactions of component molecules occur in the subsequent spinning process, resulting in spinningSilk instability; AlCl₃Catalytic methods (Mochida I, Sone Y, et al. preparation and Properties of Carbonoceous Mesophase II high hly solid Mesophase from Ethylene Tar Modified Using Alumum Chloride asA Catalyst [ J]175- & ltCHEM & gt 178.), mesophase pitch produced by the aluminum chloride catalysis method contains a large amount of cycloalkyl groups as compared with the previous methods, so that the mesophase exhibits a low softening point and a high solubility, but this method also has a fatal disadvantage that it is very difficult to completely remove aluminum chloride from pitch, a small amount of aluminum hydroxide remains in the mesophase pitch, and even a trace amount of aluminum hydroxide remains to cause a sharp decline in the performance of Carbon fibers; HF/BF₃Catalytic methods (Mochida I, Shimizu K, Korai Y, et al, preparation of media pitch from aromatic hydrocarbons by the aid of HF/BFs [ J]Carbon,1990,28(2):311-319) to prepare high spinnability mesophase pitches, but with large amounts of HF/BF₃The corrosion to the equipment is serious, which not only brings about the problems of operation safety protection, environmental protection and the like, but also makes the purification of the finally obtained asphalt more difficult due to the inevitable introduction of metal ions.

Recently Chuanzhang Ge et al synthesized a novel methylene-bridged polymer pitch (Ge C Z, Yang H X, Miyawaki J, et al Synthesis and characterization of high-absorbing-point polymers by visible light irradiation assisted free-radial polymerization [ J ]. Carbon 2015,95: 780-) 788) from 1-methylnaphthalene (1 MNP). The 1-MNP reacts with bromine under the irradiation of strong visible light to generate 1-bromomethylnaphthalene (M-Br) with single side chain substitution. Through 200-270 ℃ thermal debromination/polycondensation reaction, the high-quality isotropic pitch with the softening point of 196-250 ℃ is obtained. The prepared polymer asphalt is composed of a plurality of repeated monomers and has a linear structure of methylene bridged naphthalene rings. The price of the raw material of the 1-methylnaphthalene is higher, and the hydrogen bromide gas generated in the reaction has higher corrosivity.

Disclosure of Invention

The invention mainly aims at the problems of strong corrosion to equipment, high cost, difficult catalyst recovery and the like in the existing method for preparing the synthetic asphalt, and provides a method for preparing the synthetic asphalt and a product thereof, wherein the method has the advantages of mild reaction conditions, no catalyst residue, high product purity and wide application range.

In order to achieve the purpose, the invention provides the following technical scheme:

one of the technical schemes of the invention is as follows: the preparation method of the synthetic asphalt comprises the following specific steps:

mixing an aromatic hydrocarbon compound, concentrated hydrochloric acid, glacial acetic acid, paraformaldehyde and a catalyst, and then carrying out a Blanc chloromethylation reaction to prepare a chloromethylation product; and carrying out polymerization reaction on the prepared chloromethylation product to prepare the synthetic asphalt.

Preferably, the aromatic hydrocarbon compound is one or more of naphthalene, anthracene and anthracene oil.

Preferably, the catalyst is one or more of zinc chloride, concentrated sulfuric acid and thionyl chloride.

The catalyst used in the invention is very soluble in water, so the catalyst can be completely removed in the subsequent extraction and separation process, and the catalyst residue is avoided, thereby the synthesis of the asphalt after the catalyst residue is avoided. The zinc chloride can reduce the activation energy of the reaction and improve the conversion rate of the reaction; concentrated sulfuric acid and thionyl chloride can absorb water generated in the reaction, so that the reaction moves towards the positive direction, and the conversion rate of the reaction is improved.

Preferably, the molar ratio of the aromatic hydrocarbon compound, the concentrated hydrochloric acid, the glacial acetic acid and the paraformaldehyde is 1 (3-1) to (2-1).

Preferably, the reaction temperature of the aromatic hydrocarbon compound, the concentrated hydrochloric acid, the glacial acetic acid, the paraformaldehyde and the catalyst after mixing is 40-100 ℃, and the reaction time is 3-12 h.

Preferably, the preparation steps of the chloromethylation product are as follows: mixing an aromatic hydrocarbon compound, concentrated hydrochloric acid, glacial acetic acid, paraformaldehyde and a catalyst, reacting, extracting by using dichloromethane after the reaction is finished, separating a water phase and an organic phase, washing with a 10% potassium carbonate solution until the solution is neutral, then washing with water, and drying the washed organic phase to obtain a chloromethylation product.

Preferably, the polymerization conditions are: reacting for 3-12h at the temperature of 200-400 ℃ and the stirring speed of 200-800 r/min, wherein the whole reaction is carried out in an inert atmosphere.

Preferably, the polymerization reaction further comprises a step of impurity removal, and the impurity removal method is an extraction method.

More preferably, the extracting agent of the extraction method is one or more mixed solution of n-hexane, cyclohexane and n-heptane, and the extraction temperature is 50-100 ℃.

The second technical scheme of the invention is as follows: there is provided a synthetic asphalt produced according to the above-mentioned production method.

The invention has the following beneficial technical effects:

(1) the method provided by the invention has the advantages of low reaction temperature, low corrosivity of materials added in the reaction, capability of reacting under normal pressure, no high pressure, greatly reduced corrosion to a system and potential safety hazard caused by high pressure, mild reaction conditions and simple operation.

(2) The invention adopts a liquid phase catalysis method, and has low reaction temperature, short reaction time and low energy consumption.

(3) The reagents and raw materials used in the invention have low price and low cost, and the related reaction has high conversion rate and high yield.

Drawings

FIG. 1 is a microscopic structure view of the synthetic asphalt obtained in example 1;

FIG. 2 is a microscopic structure view of the synthetic asphalt obtained in example 2;

FIG. 3 is a microscopic structure view of the synthetic asphalt obtained in example 3.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

Example 1

128g (1mol) of naphthalene, 160mL (2mol) of concentrated hydrochloric acid, 140mL (2.2mol) of glacial acetic acid, 55g (1.8mol) of paraformaldehyde and 81mL (1.5mol) of concentrated sulfuric acid were added to a 500mL three-neck flask equipped with a stirrer and a spherical condenser constant-pressure dropping funnel, and mixed uniformly. The temperature of the water bath is raised to 60 ℃ and the reaction is carried out for 6 hours. After the reaction, 30mL of dichloromethane was added for extraction, the aqueous phase and the organic phase were separated, the organic phase was washed with 10% potassium carbonate solution to neutrality, the aqueous phase was separated, then washed with 30mL of water twice, and dried with anhydrous calcium chloride to obtain 168.9g of chloromethyl naphthalene with a yield of 96.0%.

20g of prepared chloromethyl naphthalene is placed in a three-neck flask, nitrogen is introduced, the gas flow is 60mL/min, the stirring speed is 400r/min, the reaction is carried out for 6 hours after the temperature is increased to 300 ℃, the reacted substance is placed in an extraction device, and the low components in the substance are removed by an extractant cyclohexane at the temperature of 85 ℃, so that 13.82g of synthetic asphalt is prepared, and the yield is 69.1%. The softening point was 234.0 ℃, the toluene solubles were 54.7%, and the toluene insoluble-pyridine solubles were 45.3%.

Example 2

128g (1mol) of naphthalene, 160mL (2mol) of concentrated hydrochloric acid, 140mL (2.2mol) of glacial acetic acid, 45.8g (1.5mol) of paraformaldehyde and 81mL (1.5mol) of concentrated sulfuric acid are respectively added into a 500mL three-neck flask provided with a stirrer and a spherical condenser tube constant-pressure dropping funnel, and the mixture is uniformly mixed. The temperature of the water bath is raised to 60 ℃ and the reaction is carried out for 6 hours. After the reaction, 30mL of dichloromethane is added for extraction, the aqueous phase and the organic phase are separated, the organic phase is washed by 10% potassium carbonate solution to be neutral, the aqueous phase is separated, then 30mL of water is used for washing twice, and anhydrous calcium chloride is dried to prepare 136.1g of chloromethyl naphthalene, wherein the yield is 77.3%.

20g of prepared chloromethyl naphthalene is placed in a three-neck flask, nitrogen is introduced, the gas flow is 60mL/min, the stirring speed is 400r/min, the reaction is carried out for 6 hours after the temperature is increased to 300 ℃, the reacted substance is placed in an extraction device, and the low components in the substance are removed by an extractant cyclohexane at the temperature of 85 ℃, so that 13.52g of synthetic asphalt is prepared, and the yield is 67.6%. The softening point was 230.8 ℃, the toluene solubles was 66.50%, and the toluene-insoluble-pyridine solubles was 33.50%.

Example 3

128g (1mol) of naphthalene, 160mL (2mol) of concentrated hydrochloric acid, 140mL (2.2mol) of glacial acetic acid, 55g (1.8mol) of paraformaldehyde and 81mL (1.5mol) of concentrated sulfuric acid were added to a 500mL three-neck flask equipped with a stirrer and a spherical condenser constant-pressure dropping funnel, and mixed uniformly. The temperature of the water bath is raised to 40 ℃ and the reaction is carried out for 6 hours. After the reaction, 30mL of dichloromethane was added for extraction, the aqueous phase and the organic phase were separated, the organic phase was washed with 10% potassium carbonate solution to neutrality, the aqueous phase was separated, then washed with 30mL of water twice, and dried with anhydrous calcium chloride to obtain 76.6g of chloromethyl naphthalene with a yield of 43.5%.

20g of prepared chloromethyl naphthalene is placed in a three-neck flask, nitrogen is introduced, the gas flow is 60mL/min, the stirring speed is 400r/min, the reaction is carried out for 6 hours after the temperature is increased to 300 ℃, the reacted substance is placed in an extraction device, and the low components in the substance are removed by an extractant cyclohexane at the temperature of 85 ℃, so that 13.18g of synthetic asphalt is prepared, and the yield is 65.9%. The softening point was 226.3 ℃, the toluene solubles was 66.50%, and the toluene-insoluble-pyridine solubles was 33.50%. The toluene solubles were 71.31%, and the toluene insoluble-pyridine solubles were 28.69%.

Example 4

128g (1mol) of naphthalene, 160mL (2mol) of concentrated hydrochloric acid, 140mL (2.2mol) of glacial acetic acid, 55g (1.8mol) of paraformaldehyde and 81mL (1.5mol) of concentrated sulfuric acid were added to a 500mL three-neck flask equipped with a stirrer and a spherical condenser constant-pressure dropping funnel, and mixed uniformly. The temperature of the water bath is raised to 60 ℃ and the reaction is carried out for 6 hours. After the reaction, 30mL of dichloromethane was added for extraction, the aqueous phase and the organic phase were separated, the organic phase was washed with 10% potassium carbonate solution to neutrality, the aqueous phase was separated, then washed with 30mL of water twice, and dried with anhydrous calcium chloride to obtain 168.9g of chloromethyl naphthalene with a yield of 96.0%.

20g of prepared chloromethyl naphthalene is placed in a three-neck flask, nitrogen is introduced, the gas flow is 60mL/min, the stirring speed is 400r/min, the reaction is carried out for 6 hours after the temperature is increased to 280 ℃, the reacted substance is placed in an extraction device, and the low components in the substance are removed by an extractant cyclohexane at the temperature of 85 ℃, so that 14.52g of synthetic asphalt is prepared, and the yield is 72.6%. The softening point was 212.6 ℃, the toluene solubles was 81.60%, and the toluene insoluble-pyridine solubles was 18.40%.

Example 5

178g (1mol) of anthracene, 175mL (2.2mol) of concentrated hydrochloric acid, 140mL (2.2mol) of glacial acetic acid, 55g (1.8mol) of paraformaldehyde and 5.34g of zinc chloride are respectively added into a 500mL three-neck flask equipped with a stirrer and a spherical condenser constant-pressure dropping funnel, and the materials are uniformly mixed. The temperature of the water bath is raised to 75 ℃ and the reaction is carried out for 6 hours. After the reaction, 30mL of dichloromethane was added for extraction, the aqueous phase and the organic phase were separated, the organic phase was washed with 10% potassium carbonate solution to neutrality, the aqueous phase was separated, then washed with 30mL of water twice, and dried with anhydrous calcium chloride to obtain 216.4g of chloromethylanthracene with a yield of 78.5%.

20g of prepared chloromethyl anthracene is placed in a three-neck flask, nitrogen is introduced, the gas flow is 60mL/min, the stirring speed is 500r/min, the reaction is carried out for 9 hours after the temperature is increased to 320 ℃, the reacted substance is placed in an extraction device, and the low components in the substance are removed by an extracting agent n-hexane at the temperature of 70 ℃, so that 12.58g of synthetic asphalt is prepared, and the yield is 62.9%. The softening point was 242.3 ℃, the toluene solubles were 43.3%, and the toluene insoluble-pyridine solubles were 56.7%.

Example 6

In a 500mL three-necked flask equipped with a stirrer and a dropping funnel having a spherical condenser at a constant pressure, 180g of anthracene oil, 240mL (3mol) of concentrated hydrochloric acid, 140mL (2.2mol) of glacial acetic acid, and 55g (1.8mol) of paraformaldehyde were added, respectively, and mixed uniformly. The temperature of the water bath is raised to 85 ℃, and then 240mL (3.4mol) of thionyl chloride is started to be dripped and reacted for 9 hours. After the reaction, 30mL of dichloromethane was added for extraction, the aqueous phase and the organic phase were separated, the organic phase was washed with 10% potassium carbonate solution to neutrality, the aqueous phase was separated, then washed with 30mL of water twice, and dried with anhydrous calcium chloride to obtain 232.7g of chloromethylated product with a yield of 84.6%.

And (2) placing 20g of prepared chloromethyl product in a three-neck flask, introducing nitrogen, heating to 340 ℃ at a gas flow rate of 60mL/min and a stirring speed of 600r/min for reaction for 12 hours, placing the reacted substance in an extraction device, and removing low components in the substance by using an extracting agent n-heptane at the temperature of 100 ℃ to obtain 11.20g of synthetic asphalt with the yield of 56.0%. The softening point was 268.4 ℃, toluene solubles was 26.1%, toluene-insoluble-pyridine solubles was 55.8%, and pyridine insolubles was 18.1%.

FIG. 1 is a microscopic structure diagram of a synthetic asphalt according to example 1 of the present invention, and it can be seen from FIG. 1 that the molecular structure of the synthetic asphalt is an optically isotropic structure.

FIG. 2 is a microscopic structure view of the synthetic asphalt prepared in example 2 of the present invention, and it can be seen from FIG. 2 that the molecular structure of the synthetic asphalt prepared is an optically isotropic structure.

FIG. 3 is a microscopic structure view of the synthetic asphalt prepared in example 3 of the present invention, and it can be seen from FIG. 3 that the molecular structure of the synthetic asphalt prepared is an optically isotropic structure.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.