Lignin-based quaternary ammonium salt cationic emulsifier, preparation method thereof, emulsified asphalt and application thereof
By preparing lignin-based quaternary ammonium salt cationic emulsifiers, the problems of high emulsifier cost and slow demulsification were solved, achieving rapid demulsification and good dispersion performance. This method is suitable for the preparation of emulsified asphalt and reduces production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FUJIAN TRANSPORTATION RES INST CO LTD
- Filing Date
- 2023-11-17
- Publication Date
- 2026-05-29
AI Technical Summary
Existing emulsifiers are expensive, slow to demulsify, and have poor durability, making it difficult to meet the requirements for preparing emulsified asphalt.
An emulsifier with rapid demulsification and good dispersibility was prepared by means of a ring-opening reaction of trimethylamine hydrochloride, epichlorohydrin and water, combined with the chemical reaction of sulfonated lignin.
It achieves low cost, high efficiency in demulsification and good dispersion performance, and is suitable for the preparation of emulsified asphalt, reducing production costs and improving the durability of emulsifiers.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of fine chemical technology, specifically relating to a lignin-based quaternary ammonium salt cationic emulsifier and its preparation method, as well as emulsified asphalt and its application. Background Technology
[0002] In recent years, my country's road construction has flourished, and emulsified asphalt has been widely used due to its excellent performance. The most crucial aspect of preparing emulsified asphalt lies in the emulsifier. Commonly used emulsifiers in the preparation of emulsified asphalt include alkyl polyamine emulsifiers, imidazoline emulsifiers, and gemini emulsifiers. However, the raw materials for these emulsifiers are relatively expensive, and they often suffer from slow demulsification rates and poor durability. Summary of the Invention
[0003] The purpose of this invention is to provide a lignin-based quaternary ammonium salt cationic emulsifier, its preparation method, emulsified asphalt, and its application. The lignin-based quaternary ammonium salt cationic emulsifier prepared according to the method provided by this invention exhibits rapid demulsification, good dispersion performance, and good durability, making it widely applicable in the preparation of emulsified asphalt and reducing production costs.
[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:
[0005] This invention provides a method for preparing a lignin-based quaternary ammonium salt cationic emulsifier, comprising the following steps:
[0006] Trimethylamine hydrochloride, epichlorohydrin, and water were mixed and subjected to a ring-opening reaction under alkaline conditions to obtain an intermediate.
[0007] The intermediate is mixed with sulfonated lignin and subjected to a chemical reaction to obtain a lignin-based quaternary ammonium salt cationic emulsifier.
[0008] Preferably, the mass ratio of trimethylamine hydrochloride to epichlorohydrin is 0.95–1.05:1.15–1.25.
[0009] Preferably, the conditions for the ring-opening reaction include: pH value of 8.9-9.1, temperature of 20-30℃, and time of 0.45-0.55h.
[0010] Preferably, the formaldehyde aqueous solution has a mass fraction of 38-42%; the mass ratio of lignin acetate, sodium sulfite and formaldehyde aqueous solution is 0.95-1.05:0.25-0.35:0.25-0.35.
[0011] Preferably, the conditions for the sulfonylation reaction include: pH value of 9.9-10.1, temperature of 89-91°C, and time of 1.95-2.05 h.
[0012] Preferably, the mass ratio of the intermediate to sulfonated lignin is 0.95–1.05:1.35–1.45.
[0013] Preferably, the temperature of the chemical reaction is 62-64°C and the time is 2.95-3.05 h.
[0014] This invention provides a lignin-based quaternary ammonium salt cationic emulsifier prepared by the preparation method described in the above technical solution.
[0015] This invention provides an emulsified asphalt, the raw materials of which include base asphalt and the lignin-based quaternary ammonium salt cationic emulsifier described in the above technical solution; the lignin-based quaternary ammonium salt cationic emulsifier accounts for 2.5-3% of the mass of the emulsified asphalt.
[0016] This invention provides the application of the emulsified asphalt in road construction.
[0017] This invention provides a method for preparing a lignin-based quaternary ammonium salt cationic emulsifier, comprising the following steps: mixing trimethylamine hydrochloride, epichlorohydrin, and water, and carrying out a ring-opening reaction under alkaline conditions to obtain an intermediate; mixing the intermediate with sulfonated lignin, and carrying out a combination reaction to obtain the lignin-based quaternary ammonium salt cationic emulsifier. This invention uses lignin as a raw material to prepare the lignin-based quaternary ammonium salt cationic emulsifier, resulting in low raw material costs; moreover, the lignin-based quaternary ammonium salt cationic emulsifier obtained therefrom exhibits fast demulsification speed, good dispersion performance, and good durability, and can be widely used in the preparation of emulsified asphalt. Examples show that the yield of the lignin-based quaternary ammonium salt cationic emulsifier prepared according to the method provided by this invention is 64%–70%. Detailed Implementation
[0018] This invention provides a method for preparing a lignin-based quaternary ammonium salt cationic emulsifier, comprising the following steps:
[0019] Trimethylamine hydrochloride, epichlorohydrin, and water were mixed and subjected to a ring-opening reaction under alkaline conditions to obtain an intermediate; the intermediate has the structure shown in Formula II:
[0020] The intermediate is mixed with sulfonated lignin and subjected to a chemical reaction to obtain a lignin-based quaternary ammonium salt cationic emulsifier.
[0021] In this invention, unless otherwise specified, all raw materials used are commercially available products well known to those skilled in the art or prepared using methods well known to those skilled in the art.
[0022] This invention involves mixing trimethylamine hydrochloride, epichlorohydrin, and water, and performing a ring-opening reaction under alkaline conditions to obtain an intermediate. Preferably, the preparation method of the trimethylamine hydrochloride includes the following steps: mixing trimethylamine with an aqueous hydrochloric acid solution and performing a neutralization reaction to obtain trimethylamine hydrochloride. Preferably, the mass fraction of the aqueous hydrochloric acid solution is 36-38%, more preferably 37%. Preferably, the mass ratio of trimethylamine to the aqueous hydrochloric acid solution is 0.25-0.35:0.95-1.05, more preferably 0.3:1. After mixing the trimethylamine with the aqueous hydrochloric acid solution, the pH of the resulting first mixture is preferably adjusted to 5. Preferably, hydrochloric acid is used to adjust the pH of the first mixture. There is no particular limitation on the method of pH adjustment; any method well-known to those skilled in the art can be used. Preferably, the temperature of the neutralization reaction is 20-30°C, more preferably 22-25°C; the time is preferably 0.45-0.55 h, more preferably 0.5 h. The mass ratio of trimethylamine hydrochloride to epichlorohydrin in this invention is preferably 0.95–1.05:1.15–1.25, more preferably 1:1.2. Preferably, trimethylamine hydrochloride, epichlorohydrin, and water are mixed, and then the pH of the resulting second mixture is adjusted to the alkaline conditions required for the ring-opening reaction using a pH adjuster. In this invention, the pH adjuster is preferably an aqueous sodium hydroxide solution; the mass fraction of the aqueous sodium hydroxide solution is preferably 30%. The conditions for the ring-opening reaction in this invention include: a pH value preferably of 8.9–9.1, more preferably 9; a temperature preferably of 20–30°C, more preferably 22–25°C; and a time preferably of 0.4–0.6 h, more preferably 0.5 h.
[0023] The intermediate described in this invention has the structure shown in Formula I:
[0024]
[0025] After the ring-opening reaction described in this invention, no post-processing is required, and subsequent combination reactions can be carried out directly.
[0026] After obtaining the intermediate, the present invention mixes the intermediate with sulfonated lignin and performs a chemical reaction to obtain a lignin-based quaternary ammonium salt cationic emulsifier. Preferably, the present invention mixes lignin acetate, sodium sulfite, and an aqueous formaldehyde solution, and performs a sulfonation reaction under alkaline conditions to obtain sulfonated lignin. In the present invention, the sodium sulfite is preferably anhydrous sodium sulfite. In the present invention, the mass fraction of the aqueous formaldehyde solution is preferably 38-42%, more preferably 40%. The mass ratio of the lignin acetate, sodium sulfite, and aqueous formaldehyde solution is preferably 0.95-1.05:0.25-0.35:0.25-0.35, more preferably 1:0.3:0.3. Preferably, the present invention first mixes lignin acetate, sodium sulfite, and water to obtain a third mixture; then adds the aqueous formaldehyde solution to the third mixture, and then adjusts the pH value to the alkaline conditions required for the sulfonation reaction using a pH adjuster to perform the sulfonation reaction. In the present invention, the pH adjuster is preferably a sodium hydroxide solution. In this invention, the formaldehyde aqueous solution is preferably added dropwise to the third mixture, more preferably dropwise. In this invention, the conditions for the sulfonation reaction include: a pH value preferably of 9.9–10.1, more preferably 10; a temperature preferably of 89–91°C, more preferably 90°C; and a time preferably of 1.95–2.05 h, more preferably 2 h. In this invention, the mass ratio of the intermediate to sulfonated lignin is preferably 0.95–1.05:1.35–1.45, more preferably 1:1.4. In this invention, the temperature of the combination reaction is preferably 62–64°C, more preferably 63°C; and the time is preferably 2.95–3.05 h, more preferably 3 h. After the combination reaction is completed, this invention preferably uses distillation to obtain the lignin-based quaternary ammonium salt cationic emulsifier. In this invention, the distillation method is preferably vacuum distillation. This invention does not have specific limitations on the specific operation of the distillation; distillation operations well known to those skilled in the art can be used.
[0027] This invention provides a lignin-based quaternary ammonium salt cationic emulsifier prepared by the preparation method described in the above technical solution. In this invention, the structural formula of the lignin-based quaternary ammonium salt cationic emulsifier is shown in Formula II:
[0028]
[0029] In this context, A stands for lignin.
[0030] This invention uses lignin as a raw material to prepare lignin-based quaternary ammonium salt cationic emulsifiers, which not only has low raw material costs, but also results in lignin-based quaternary ammonium salt cationic emulsifiers with fast demulsification speed, good dispersion performance, and good durability, making them widely applicable to the preparation of emulsified asphalt. Furthermore, the preparation method of the lignin-based quaternary ammonium salt cationic emulsifiers described in this invention is simple, time-saving, and has a high yield.
[0031] This invention also provides an emulsified asphalt, the raw materials of which include base asphalt and the lignin-based quaternary ammonium salt cationic emulsifier described in the above-mentioned technical solution. In this invention, the base asphalt is preferably 70# base asphalt and / or 90# base asphalt. In this invention, the mass percentage of the lignin-based quaternary ammonium salt cationic emulsifier in the emulsified asphalt is preferably 2.5-3%, more preferably 2.6-2.8%. The raw materials for preparing the emulsified asphalt of this invention also preferably include a pH adjuster, a stabilizer, and a modifier. In this invention, the pH adjuster preferably includes a sodium hydroxide aqueous solution with a mass fraction of 36-38%; the stabilizer is preferably anhydrous calcium chloride; and the modifier is preferably styrene-butadiene rubber latex and / or waterborne epoxy resin. In this invention, the preferred mass ratio of the lignin-based quaternary ammonium salt cationic emulsifier, pH adjuster, stabilizer, and modifier is 0.95–1.05: 0.85–0.95: 0.005–0.015: 0.005–0.015, more preferably 1: 0.9: 0.01: 0.01. This invention preferably mixes the above-mentioned raw materials to obtain emulsified asphalt. This invention does not impose any particular limitation on the mixing method of the raw materials for preparing emulsified asphalt; any mixing method well known to those skilled in the art can be used.
[0032] The present invention also provides the application of the emulsified asphalt in road construction.
[0033] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0034] Base bitum (name: 70# base bitumum, produced by Shell (China) Limited);
[0035] All reagents used in the embodiments of this invention are commercially available.
[0036] Example 1
[0037] At 23°C, trimethylamine was mixed with a 37wt% hydrochloric acid aqueous solution at a mass ratio of 0.3:1. The pH was adjusted to 5 with hydrochloric acid, and the reaction was allowed to proceed for 0.5 h to obtain a solution containing trimethylamine hydrochloride. Epichlorohydrin was added to the solution containing trimethylamine hydrochloride (the mass ratio of trimethylamine hydrochloride to epichlorohydrin was 1:1.2). The pH of the solution was adjusted to 9 with a 30% sodium hydroxide aqueous solution, and the reaction was allowed to proceed for 0.5 h at 23°C to obtain an intermediate.
[0038] Acetic lignin and sodium sulfite were mixed with water at a mass ratio of 1:0.3, and then a 40wt% formaldehyde aqueous solution was added dropwise. The pH value was adjusted to 10 with sodium hydroxide aqueous solution, and the reaction was carried out at 90℃ for 2 hours to obtain sulfonated lignin.
[0039] The intermediate was mixed with the sulfonated lignin at a mass ratio of 1:1.4 and reacted at 63°C for 3 hours. After vacuum distillation, a lignin-based quaternary ammonium salt cationic emulsifier was obtained.
[0040] The results showed that the yield of the lignin-based quaternary ammonium salt cationic emulsifier prepared according to the method provided in this invention was 70%.
[0041] Example 2
[0042] The lignin-based quaternary ammonium salt cationic emulsifier was prepared according to the method described in Example 1, except that during the preparation of the intermediate, 20.0 g, 22.5 g, 25.0 g, 27.5 g, 30.0 g, 32.5 g, and 35.0 g of a 30% sodium hydroxide aqueous solution were added dropwise within 10 to 30 minutes after the addition of epichlorohydrin.
[0043] 200g of base asphalt was mixed with 5g of the obtained lignin-based quaternary ammonium salt cationic emulsifier, 4.5g of pH adjuster, 0.05g of stabilizer, and 0.05g of modifier to obtain emulsified asphalt.
[0044] The effect of the amount of 30% sodium hydroxide aqueous solution on the stability of the obtained emulsified asphalt is shown in Table 1.
[0045] Table 1. Effect of the amount of 30% sodium hydroxide aqueous solution on the stability of the obtained emulsified asphalt.
[0046] Dosage of 30% sodium hydroxide aqueous solution (g) Emulsified asphalt stability 20.0 better 22.5 better 25.0 better 27.5 good 30.0 good 35.0 Unstable
[0047] As shown in Table 1, the amount of sodium hydroxide aqueous solution in the emulsifier affects the emulsification effect of the emulsifier, i.e. the stability of the emulsified asphalt. When the amount of sodium hydroxide aqueous solution is 27.5-30.0 g, the emulsified asphalt has the best stability.
[0048] Example 3
[0049] A lignin-based quaternary ammonium salt cationic emulsifier was prepared according to the method described in Example 1.
[0050] 200g of base asphalt was mixed with 5g of the obtained lignin-based quaternary ammonium salt cationic emulsifier, 4.5g of pH adjuster, 0.05g of stabilizer, and 0.05g of modifier to obtain emulsified asphalt.
[0051] Example 4
[0052] A lignin-based quaternary ammonium salt cationic emulsifier was prepared according to the method described in Example 1.
[0053] 200g of base asphalt was mixed with 6g of the obtained lignin-based quaternary ammonium salt cationic emulsifier, 5.4g of pH adjuster, 0.06g of stabilizer, and 0.06g of modifier to obtain emulsified asphalt.
[0054] Comparative Example 1
[0055] A lignin-based quaternary ammonium salt cationic emulsifier was prepared according to the method described in Example 1.
[0056] 200g of base asphalt was mixed with 0.6g of the obtained lignin-based quaternary ammonium salt cationic emulsifier, 0.54g of pH adjuster, 0.006g of stabilizer, and 0.006g of modifier to obtain emulsified asphalt.
[0057] Comparative Example 2
[0058] A lignin-based quaternary ammonium salt cationic emulsifier was prepared according to the method described in Example 1.
[0059] 200g of base asphalt was mixed with 1.6g of the obtained lignin-based quaternary ammonium salt cationic emulsifier, 1.44g of pH adjuster, 0.016g of stabilizer, and 0.016g of modifier to obtain emulsified asphalt.
[0060] Comparative Example 3
[0061] A lignin-based quaternary ammonium salt cationic emulsifier was prepared according to the method described in Example 1.
[0062] 200g of base asphalt was mixed with 3.2g of the obtained lignin-based quaternary ammonium salt cationic emulsifier, 2.88g of pH adjuster, 0.032g of stabilizer, and 0.032g of modifier to obtain emulsified asphalt.
[0063] Comparative Example 4
[0064] A lignin-based quaternary ammonium salt cationic emulsifier was prepared according to the method described in Example 1.
[0065] 200g of base asphalt was mixed with 7g of the obtained lignin-based quaternary ammonium salt cationic emulsifier, 6.3g of pH adjuster, 0.07g of stabilizer, and 0.07g of modifier to obtain emulsified asphalt.
[0066] The emulsification effect of the emulsified asphalt obtained in Examples 3-4 and Comparative Examples 1-4 was observed to investigate the effect of emulsifier dosage on the emulsification effect of asphalt (the pH value of the lignin quaternary ammonium salt cationic emulsifier was 1-2, the temperature of the base asphalt was 120℃, the temperature of the lignin quaternary ammonium salt cationic emulsifier was 60℃, and the oil-water ratio was 55:45). The results are shown in Table 2.
[0067] Table 2. Effect of lignin-based quaternary ammonium salt cationic emulsifier dosage on asphalt emulsification effect.
[0068]
[0069]
[0070] Table 2 shows that, at a constant pH and temperature, a low dosage of lignin-based quaternary ammonium salt cationic emulsifier results in poor emulsification and incomplete emulsification. As the dosage increases, the demulsification time lengthens, leading to better emulsification. However, excessive dosage negatively impacts the emulsified asphalt, reducing the performance of the base asphalt and increasing production costs. Therefore, the emulsified asphalt exhibits the best performance when the mass percentage of lignin-based quaternary ammonium salt cationic emulsifier in the emulsified asphalt is 2.5–3%.
[0071] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.
Claims
1. A method for preparing a lignin-based quaternary ammonium salt cationic emulsifier, comprising the following steps: Trimethylamine hydrochloride, epichlorohydrin, and water were mixed and subjected to a ring-opening reaction under alkaline conditions to obtain an intermediate. The mass ratio of trimethylamine hydrochloride to epichlorohydrin is 1:1.2; the conditions for the ring-opening reaction include: pH 9, temperature 23°C, and time 0.5 h. The intermediate is mixed with sulfonated lignin and subjected to a chemical reaction to obtain a lignin-based quaternary ammonium salt cationic emulsifier. The method for preparing the sulfonated lignin is as follows: lignin acetate, sodium sulfite, and formaldehyde aqueous solution are mixed and subjected to sulfonation reaction under alkaline conditions to obtain the sulfonated lignin; the mass fraction of the formaldehyde aqueous solution is 40%; the mass ratio of lignin acetate to sodium sulfite is 1:0.3; the conditions for the sulfonation reaction include: pH value of 10, temperature of 90℃, and time of 2h. The mass ratio of the intermediate to sulfonated lignin is 1:1.4; The reaction was carried out at a temperature of 63°C for 3 hours.
2. The lignin-based quaternary ammonium salt cationic emulsifier prepared by the preparation method of claim 1.
3. An emulsified asphalt, the raw materials for which preparation comprises base asphalt and the lignin-based quaternary ammonium salt cationic emulsifier as described in claim 2; wherein the lignin-based quaternary ammonium salt cationic emulsifier accounts for 2.5-3% by mass in the emulsified asphalt; The raw materials for preparation also include: pH adjusters, stabilizers, and modifiers; The pH adjuster is a sodium hydroxide aqueous solution with a mass fraction of 36-38%; The stabilizer is anhydrous calcium chloride; The modifier is styrene-butadiene rubber latex and / or waterborne epoxy resin; The mass ratio of the lignin-based quaternary ammonium salt cationic emulsifier, pH adjuster, stabilizer, and modifier is 1:0.9:0.01:0.
01.
4. The application of the emulsified asphalt according to claim 3 in road construction.