Preparation method of novel kitchen oil stain cleaning surfactant

Abstract

The invention relates to the field of surfactants, and discloses a preparation method of a novel kitchen oil stain cleaning surfactant, which comprises the following steps: S1, selecting dodecyl amine and ethylene oxide as raw materials, and adding into a reaction kettle; s2, adding a neutralizing agent to prepare an intermediate dodecyl amine dipolyoxyethylene ether; s3, adding dodecyl amine dipolyoxyethylene ether and chloromethane into a reaction kettle, and then adding a medium solvent to obtain N-dodecyl methyl dipolyoxyethylene ether ammonium chloride; s4, adding N-dodecyl methyl dipolyoxyethylene ether ammonium chloride and potassium hydroxide into absolute ethyl alcohol; and S5, after the reaction is finished, filtering and evaporating the solution at a low temperature to obtain the N-dodecyl methyl dipolyoxyethylene ether ammonium hydroxide. According to the invention, dodecyl amine is combined with an oxyethylated hydrophilic group, so that the obtained product has the properties of cationic and nonionic surfactants at the same time, and the complexity of compounding of multiple surfactants is avoided.

Description

Technical Field

[0001] The invention relates to the field of surfactants, in particular to a method for preparing a novel surfactant for cleaning kitchen greasy dirt. Background Art

[0002] Surfactants for cleaning kitchen grease are a class of chemicals specifically used to remove grease from kitchen surfaces. They can significantly reduce the surface tension of water, thereby effectively emulsifying, dispersing and dissolving stubborn grease and dirt, making them easy to rinse off. The structure of surfactants usually contains a hydrophilic part (easy to combine with water molecules) and a lipophilic part (easy to combine with grease molecules). It is this amphiphilic structure that enables it to react with grease and emulsify or dissolve it in water.

[0003] The patent application with publication number CN118207048A discloses a kitchen heavy oil cleaner with anionic surfactant, nonionic surfactant and alkaline additive as raw materials and its preparation method. The patent application with publication number CN102899193A discloses a new environmentally friendly and efficient oil cleaning agent with dry waste silicon slag, anionic surfactant, nonionic surfactant, cationic surfactant and sodium hydroxide as raw materials and its preparation method. However, there are two problems: first, multiple surfactants need to be compounded and added with strong alkali to achieve a better degreasing effect, and second, the surfactant content and alkalinity are fixed.

[0004] The combination of multiple surfactants and strong alkali not only increases the complexity of the formula, but also causes interference between surfactants, reducing the stability and long-term effectiveness of the detergent. Fixed surfactant content and alkalinity will lead to users facing the problem of over-cleaning or poor cleaning effect. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for preparing a novel surfactant for cleaning kitchen oil stains, which solves the problem in the prior art that the compounding of multiple surfactants increases the complexity of the formula, causes mutual interference between the surfactants, reduces the stability and long-term effectiveness of the cleaning agent, and the fixed surfactant content and alkalinity may cause users to face the problem of excessive cleaning or poor cleaning effect.

[0006] To achieve the above objectives, the present invention is implemented by the following technical scheme: A method for preparing a novel surfactant for cleaning kitchen grease, comprising the following steps:

[0007] S1, selecting dodecylamine and ethylene oxide as raw materials and adding them into a reaction kettle, adding a catalyst under anhydrous and oxygen-free conditions, and performing an oxyethylation addition reaction;

[0008] S2, after the reaction is completed, the reaction is cooled, and a neutralizing agent is added until the reactants are neutral to obtain an intermediate dodecylamine dipolyoxyethylene ether;

[0009] S3, adding dodecylamine dimeroxyethylene ether and methyl chloride into a reaction kettle, and then adding a medium solvent, and performing recrystallization after the reaction is completed to obtain N-dodecylmethyl dimeroxyethylene ether ammonium chloride;

[0010] S4, adding N-dodecylmethyl dimeroxyethylene ether ammonium chloride and potassium hydroxide into anhydrous ethanol, and stirring at room temperature;

[0011] S5. After the reaction is completed, filter out the precipitated potassium chloride solid, and then evaporate the solution at low temperature to obtain N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide.

[0012] Preferably, the catalyst in S1 is an alkaline catalyst, and the alkaline catalyst includes sodium hydroxide, potassium hydroxide and anhydrous sodium carbonate solid. The neutralizer in S2 is acetic acid, and after neutralization, a bleaching agent is added to improve the color of dodecylamine dipolyoxyethylene ether, and the bleaching agent is hydrogen peroxide.

[0013] Preferably, in S1, the reactor is a high-pressure stainless steel reactor to achieve anhydrous and oxygen-free conditions, and the reaction temperature is 140-160° C., the reaction pressure is 0.15-0.3 MPa, and the reaction time is 4-6 h.

[0014] Preferably, the mass ratios of the dodecylamine, ethylene oxide, alkaline catalyst, acetic acid and hydrogen peroxide are 1:(3.9-4.1):(0.002-0.003):(0.16-0.18):(0.08-0.11) respectively.

[0015] Preferably, the reaction temperature in S3 is 80-90° C., the reaction pressure is 0.3-0.5 MPa, and the reaction time is 1-2 h.

[0016] Preferably, in S3, the medium solvent is petroleum ether, and the temperature is lowered after the reaction is completed to allow N-dodecylmethyl dimeroxyethylene ether ammonium chloride to recrystallize and precipitate.

[0017] Preferably, the mass ratios of the dodecylamine dimeroxyethylene ether, methyl chloride, and solvent petroleum ether are (16.0-16.8):1:(9.2-9.7) respectively.

[0018] Preferably, the reaction temperature and pressure in S4 are normal temperature and pressure, and the reaction time is 0.5 to 1 h.

[0019] Preferably, the mass ratios of N-dodecylmethyl dimeroxyethylene ether ammonium chloride, potassium hydroxide and anhydrous ethanol in S4 are (15.2-16.2):1:(5.7-6.5) respectively.

[0020] Preferably, in S5, the filtering device is a vacuum filter, the pore size of the filter paper or filter membrane used is 0.45-1.0 μm, and after obtaining the filtrate, a low-temperature evaporation device is used, the evaporation temperature is 40-50° C., the vacuum degree is 0.08-0.09 MPa, and the evaporation time is 1-2 h.

[0021] The present invention provides a method for preparing a novel surfactant for cleaning kitchen oil stains. It has the following beneficial effects:

[0022] 1. The present invention conducts an oxyethylation reaction of dodecylamine and ethylene oxide, and utilizes the combination of the amine group in dodecylamine and the hydrophilic group after oxyethylation, so that the obtained product has the properties of both cationic (amine group) and non-ionic (polyoxyethylene) surfactants, thereby improving the adsorption and cleaning capabilities of oil stains and avoiding the problem of increasing the complexity of the formula by compounding multiple surfactants.

[0023] 2. The present invention generates N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide by reacting N-dodecylmethyl dimeroxyethylene ether ammonium chloride with potassium hydroxide, and utilizes its strong alkalinity, so that the decontamination ability of the detergent can be directly enhanced without relying on other strong alkaline additives.

[0024] 3. The present invention uses the solvent petroleum ether to recrystallize N-dodecylmethyl dimeroxyethylene ether ammonium chloride, and utilizes its good solubility and recrystallization characteristics to improve the purity and stability of the surfactant, thereby enhancing the decontamination effect of the detergent. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure is a schematic diagram of the chemical molecular structure of N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Please see attached Figure 1 The present invention provides a novel method for preparing a surfactant for cleaning kitchen oil stains, comprising the following steps:

[0028] S1, selecting dodecylamine and ethylene oxide as raw materials and adding them into a reaction kettle, adding a catalyst under anhydrous and oxygen-free conditions, and performing an oxyethylation addition reaction;

[0029] S2, after the reaction is completed, the reaction is cooled, and a neutralizing agent is added until the reactants are neutral to obtain an intermediate dodecylamine dipolyoxyethylene ether;

[0030] S3, adding dodecylamine dimeroxyethylene ether and methyl chloride into a reaction kettle, and then adding a medium solvent, and performing recrystallization after the reaction is completed to obtain N-dodecylmethyl dimeroxyethylene ether ammonium chloride;

[0031] S4, adding N-dodecylmethyl dimeroxyethylene ether ammonium chloride and potassium hydroxide into anhydrous ethanol, and stirring at room temperature;

[0032] S5. After the reaction is completed, filter out the precipitated potassium chloride solid, and then evaporate the solution at low temperature to obtain N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide.

[0033] The catalyst in S1 is an alkaline catalyst, which includes sodium hydroxide, potassium hydroxide and anhydrous sodium carbonate solid. The neutralizer in S2 is acetic acid, and after neutralization, a bleaching agent is added to improve the color of dodecylamine dipolyoxyethylene ether, and the bleaching agent is hydrogen peroxide. In S1, the reactor is a high-pressure stainless steel reactor to achieve anhydrous and oxygen-free conditions, and the reaction temperature is 140-160°C, the reaction pressure is 0.15-0.3MPa, and the reaction time is 4-6h.

[0034] The mass ratios of dodecylamine, ethylene oxide, alkaline catalyst, acetic acid and hydrogen peroxide are 1:(3.9-4.1):(0.002-0.003):(0.16-0.18):(0.08-0.11) respectively.

[0035] In S3, the reaction temperature is 80-90°C, the reaction pressure is 0.3-0.5 MPa, and the reaction time is 1-2 hours. In S3, the medium solvent is petroleum ether, and the temperature is lowered after the reaction is completed to allow N-dodecylmethyl dimeroxyethylene ether ammonium chloride to recrystallize and precipitate.

[0036] The mass ratios of dodecylamine dimeroxyethylene ether, methyl chloride and solvent petroleum ether are (16.0-16.8):1:(9.2-9.7) respectively.

[0037] The reaction temperature and pressure in S4 are normal temperature and pressure, and the reaction time is 0.5 to 1 hour. The mass ratios of N-dodecylmethyl dimeroxyethylene ether ammonium chloride, potassium hydroxide, and anhydrous ethanol in S4 are (15.2 to 16.2):1:(5.7 to 6.5) in sequence.

[0038] In S5, the filtering equipment is a vacuum filter, the pore size of the filter paper or filter membrane used is 0.45-1.0 μm, and after obtaining the filtrate, a low-temperature evaporation device is used, the evaporation temperature is 40-50°C, the vacuum degree is 0.08-0.09 MPa, and the evaporation time is 1-2 hours.

[0039] The chemical name of the final product is N-dodecyl methyl dimeroxyethylene ether ammonium hydroxide, wherein m and n in the molecular formula are 8, 10 or 12.

[0040] Embodiment 1:

[0041] Specific steps:

[0042] S1: 16.0 g of dodecylamine and 64.0 g of ethylene oxide were selected and added into a reactor. Under anhydrous and oxygen-free conditions, 0.032 g of sodium hydroxide was added as a catalyst. The reaction temperature was 150° C., the pressure was 0.2 MPa, and the reaction time was 5 hours to carry out an oxyethylation addition reaction.

[0043] S2: After cooling, 2.56 g of acetic acid was added to neutralize the reactant. The reactant was neutral, and 1.28 g of hydrogen peroxide was added for bleaching to obtain dodecylamine dimeroxyethylene ether.

[0044] S3: Add dodecylamine dimeroxyethylene ether and 4.8 g of methyl chloride into a reactor, use 45 g of petroleum ether as a solvent, react at a temperature of 85° C., a pressure of 0.4 MPa, and a reaction time of 1.5 hours to obtain N-dodecylmethyl dimeroxyethylene ether ammonium chloride after recrystallization.

[0045] S4: Add 5.3 g of potassium hydroxide and 31.8 g of anhydrous ethanol, and stir at room temperature and pressure for 0.7 hours.

[0046] S5: Filter out the potassium chloride solid, filter it with a vacuum filter with a pore size of 0.45 μm, and use low-temperature evaporation at 40° C., vacuum degree 0.085 MPa, and evaporation time 1.5 hours to obtain N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide.

[0047] Summary: This embodiment obtains a high-purity surfactant under moderate reaction temperature and pressure, which has strong decontamination ability and is suitable for cleaning medium-difficulty oil stains.

[0048] Embodiment 2

[0049] Specific steps:

[0050] S1: 16.4 g of dodecylamine and 65.6 g of ethylene oxide were selected and added into a reactor. Under anhydrous and oxygen-free conditions, 0.033 g of sodium hydroxide was added as a catalyst. The reaction temperature was 160° C., the pressure was 0.25 MPa, and the time was 4 hours to carry out an oxyethylation addition reaction.

[0051] S2: After cooling, 2.60 g of acetic acid was added to neutralize the reactant. The reactant was neutral, and 1.30 g of hydrogen peroxide was added for bleaching to obtain dodecylamine dimeroxyethylene ether.

[0052] S3: Add dodecylamine dimeroxyethylene ether and 5.0 g of methyl chloride into a reactor, use 46 g of petroleum ether as a solvent, the reaction temperature is 90° C., the pressure is 0.35 MPa, the time is 1.8 hours, and N-dodecylmethyl dimeroxyethylene ether ammonium chloride is obtained after recrystallization.

[0053] S4: Add 5.5 g of potassium hydroxide and 32.5 g of anhydrous ethanol, and stir at room temperature and pressure for 0.6 hour.

[0054] S5: Filter the potassium chloride solid, filter it with a vacuum filter with a pore size of 0.45 μm, evaporate it at a low temperature of 45° C., a vacuum degree of 0.08 MPa, and an evaporation time of 1.2 hours to obtain N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide.

[0055] Summarize:

[0056] In this embodiment, the reaction temperature and time are adjusted, the reaction conditions are relatively mild, the solvent used in the recrystallization process is slightly changed, and the obtained surfactant has a better purity.

[0057] Embodiment 3

[0058] Specific steps:

[0059] S1: 15.8 g of dodecylamine and 63.2 g of ethylene oxide were selected and added into a reactor. Under anhydrous and oxygen-free conditions, 0.030 g of potassium hydroxide was added as a catalyst. The reaction temperature was 145° C., the pressure was 0.18 MPa, and the reaction time was 6 hours to carry out an oxyethylation addition reaction.

[0060] S2: After cooling, 2.52 g of acetic acid was added to neutralize the reactant. The reactant was neutral, and 1.25 g of hydrogen peroxide was added for bleaching to obtain dodecylamine dimeroxyethylene ether.

[0061] S3: Add dodecylamine dimeroxyethylene ether and 4.7 g of methyl chloride into a reactor, use 44 g of petroleum ether as a solvent, the reaction temperature is 80° C., the pressure is 0.3 MPa, the time is 1 hour, and N-dodecylmethyl dimeroxyethylene ether ammonium chloride is obtained after recrystallization.

[0062] S4: Add 5.1 g of potassium hydroxide and 30.5 g of anhydrous ethanol, and stir at room temperature and pressure for 0.8 hours.

[0063] S5: Filter the potassium chloride solid, filter it with a vacuum filter with a pore size of 0.50 μm, evaporate it at a low temperature of 35° C., a vacuum degree of 0.09 MPa, and an evaporation time of 2 hours to obtain N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide.

[0064] Summarize:

[0065] This embodiment reduces the reaction temperature and pressure, prolongs the reaction time, and slightly improves the purity of the final product, but takes a long time and is suitable for mass production that is not urgently needed.

[0066] Embodiment 4

[0067] Specific steps:

[0068] S1: 16.2 g of dodecylamine and 64.8 g of ethylene oxide were selected and added into a reactor. Under anhydrous and oxygen-free conditions, 0.034 g of sodium hydroxide was added as a catalyst. The reaction temperature was 155° C., the pressure was 0.22 MPa, and the reaction time was 4.5 hours to carry out an oxyethylation addition reaction.

[0069] S2: After cooling, 2.58 g of acetic acid was added to neutralize the reactant. The reactant was neutral, and 1.29 g of hydrogen peroxide was added for bleaching to obtain dodecylamine dipolyoxyethylene ether.

[0070] S3: Add dodecylamine dimeroxyethylene ether and 4.9 g of methyl chloride into a reactor, use 45 g of petroleum ether as a solvent, the reaction temperature is 85° C., the pressure is 0.35 MPa, the time is 1.3 hours, and N-dodecylmethyl dimeroxyethylene ether ammonium chloride is obtained after recrystallization.

[0071] S4: Add 5.4 g of potassium hydroxide and 32.2 g of anhydrous ethanol, and stir at room temperature and pressure for 0.7 hours.

[0072] S5: Filter the potassium chloride solid, filter it with a vacuum filter with a pore size of 0.45 μm, evaporate it at a low temperature of 42° C., a vacuum degree of 0.085 MPa, and an evaporation time of 1.4 hours to obtain N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide.

[0073] Summarize:

[0074] This embodiment obtains relatively balanced reaction conditions by fine-tuning the temperature and pressure, thereby ensuring the high efficiency of the reaction and the purity of the product.

[0075] Embodiment 5

[0076] Specific steps:

[0077] S1: 16.3 g of dodecylamine and 65.2 g of ethylene oxide were selected and added into a reactor. Under anhydrous and oxygen-free conditions, 0.035 g of sodium hydroxide was added as a catalyst. The reaction temperature was 150° C., the pressure was 0.2 MPa, and the reaction time was 5.5 hours to carry out an oxyethylation addition reaction.

[0078] S2: After cooling, 2.60 g of acetic acid was added to neutralize the reactant. The reactant was neutral, and 1.30 g of hydrogen peroxide was added for bleaching to obtain dodecylamine dipolyoxyethylene ether.

[0079] S3: Add dodecylamine dimeroxyethylene ether and 5.1 g of methyl chloride into a reactor, use 46 g of petroleum ether as a solvent, the reaction temperature is 90° C., the pressure is 0.4 MPa, and the reaction time is 1.7 hours. After recrystallization, N-dodecylmethyl dimeroxyethylene ether ammonium chloride is obtained.

[0080] S4: Add 5.6 g of potassium hydroxide and 33 g of anhydrous ethanol, and stir at room temperature and pressure for 0.6 hours.

[0081] S5: Filter the potassium chloride solid, filter it with a vacuum filter with a pore size of 0.45 μm, evaporate it at a low temperature of 43° C., a vacuum degree of 0.082 MPa, and an evaporation time of 1.6 hours to obtain N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide.

[0082] Summarize:

[0083] This embodiment is slightly different from other embodiments in temperature, pressure and time. The purity of the product is higher and it is suitable for medium-scale production needs.

[0084] Test experiments and test data

[0085] Test conditions:

[0086] Test material: kitchen grease (fatty acids, vegetable oil mixture)

[0087] Test temperature: 25℃

[0088] Cleaning agent (N-dodecyl methyl ammonium hydroxide) concentration: 1% aqueous solution (the volume ratio of N-dodecyl methyl ammonium hydroxide to clean water is 1:100)

[0089] Test time: 5 minutes

[0090] Test method: Apply standard oil stains on the stainless steel plate, let it stand for 5 minutes, and then scrub it with the corresponding cleaning agent.

[0091] Experimental data table:

[0092]

[0093] Through detailed analysis of the experimental data tables, combined with the differences in the proportions of the components in each embodiment, the specific advantages of each embodiment are evaluated, and its cleaning performance and purity are deeply analyzed.

[0094] 1. Cleaning rate analysis

[0095] The cleaning rates of the various embodiments range from 91.8% to 93.2%, with little difference, but slight differences in components lead to performance differences among the embodiments.

[0096] The cleaning rates of Example 5 (93.2% cleaning rate) and Example 2 (93.0% cleaning rate) are the highest because the amount of ethylene oxide used in these two examples is relatively high (the ratio of ethylene oxide to dodecylamine is closer to 4:1), and the combination of reaction temperature and pressure is the most moderate, which not only ensures the full combination of ethoxy groups, but also avoids side reactions caused by overly intense reaction conditions.

[0097] The cleaning rate of Example 3 is the lowest (91.8%), reflecting the negative impact of lower reaction temperature and pressure on cleaning ability. Due to the lower temperature and pressure, the oxyethylation reaction is slower, the average polymerization degree n of the polyoxyethylene group decreases, and the surface activity of the product is slightly inferior.

[0098] 2. Effect of reaction temperature and pressure

[0099] The effects of reaction temperature and pressure in each example are very significant and have a significant impact on the cleaning efficiency and purity of the product.

[0100] The reaction temperature and pressure of Example 2 are the highest among all the examples (160° C., 0.25 MPa). Under high temperature and high pressure conditions, the oxyethylation reaction is rapid and thorough, and the hydrophilic group and the lipophilic group in the product are well combined, thereby improving the performance of the surfactant. Although this is conducive to improving the cleaning rate, too high reaction conditions will also increase the generation of by-products, so the amount of potassium chloride precipitated in this example (5.3 g) is slightly higher.

[0101] Example 3 uses the lowest reaction temperature and pressure (145° C., 0.18 MPa). Although this reduces energy consumption and reaction intensity, it also reduces reaction efficiency, resulting in relatively low cleaning rate and purity.

[0102] 3. Relationship between the precipitation amount of potassium hydroxide and potassium chloride

[0103] The amount of potassium hydroxide used and the amount of potassium chloride precipitated can reflect the thoroughness of the reaction between N-dodecylmethyl dimeroxyethylene ether ammonium chloride and potassium hydroxide.

[0104] The amount of potassium hydroxide used in Example 5 is the largest (5.6 g), and the amount of potassium chloride precipitated is also the highest (5.4 g). This shows that the reaction is complete in this example, and the activity of the detergent is maximized, so the cleaning rate and purity are both optimal (93.2% cleaning rate, 99.2% purity).

[0105] The amount of potassium hydroxide used and the amount of potassium chloride precipitated in Example 3 were both relatively low (5.1 g, 5.0 g), which was consistent with its relatively low cleaning rate and purity (97.8%). This indicates that the reaction was not fully carried out at relatively low temperature and pressure.

[0106] 4. Purity Analysis

[0107] Detergents with higher purity usually have better stability and cleaning effect, indicating that there are fewer reaction by-products and the reaction conditions are reasonably controlled.

[0108] The detergent of Example 5 has the highest purity (99.2%), which reflects that the reaction is thorough and the side reactions are less under moderate temperature and pressure. In addition, the higher amount of potassium hydroxide also helps to improve the reaction efficiency.

[0109] The purity of Example 3 is the lowest (97.8%), which again shows that lower reaction temperature and pressure are not conducive to the thoroughness of the reaction. Incomplete reaction leads to some unreacted raw materials remaining, which reduces the purity.

[0110] 5. Influence of component ratio

[0111] The differences in the ratios of the components in the various examples (especially the ratio of dodecylamine to ethylene oxide) have a significant effect on the cleaning rate and purity of the product.

[0112] In Example 5, the ratio of dodecylamine to ethylene oxide is close to 1:4 (16.3 g dodecylamine: 65.2 g ethylene oxide), which is a relatively ideal ratio, so that the ratio of hydrophilic groups and lipophilic groups in the product is coordinated, which helps to improve the cleaning ability and stability.

[0113] In Example 3, the amount of ethylene oxide used is slightly lower (15.8 g dodecylamine: 63.2 g ethylene oxide), which reduces the average degree of polymerization n of the polyoxyethylene groups, thereby making its surface activity relatively low, resulting in a cleaning rate and purity that are inferior to those of other examples.

[0114] 6. Summary Analysis

[0115] Through comparative analysis among various embodiments, the following conclusions can be drawn:

[0116] Example 5 performs best in all indicators, especially in cleaning rate and purity, thanks to moderate temperature, pressure and component ratio, as well as a higher amount of potassium hydroxide. The reaction conditions of this example balance the relationship between efficiency and side reactions, and is the most promising solution.

[0117] Example 2 has a high cleaning rate under high temperature and high pressure conditions, but it is necessary to control the side reactions, especially the precipitation of potassium chloride, and is suitable for small batch rapid production.

[0118] The reaction conditions of Example 3 are the mildest and suitable for occasions with low energy consumption requirements, but its cleaning rate and purity are slightly inferior. The main disadvantage is that the reaction is incomplete, which affects the activity and stability of the product.

[0119] Embodiment 4 achieves a balance between cleaning rate and purity by slightly increasing the reaction temperature and pressure, which is suitable for medium-scale production and has a relatively balanced performance. Therefore, factories with large production scales may give priority to embodiment 5, which has the best comprehensive performance and is suitable for efficient large-scale production. Factories with lower energy consumption requirements may choose embodiment 3, which maintains the basic cleaning effect while reducing the temperature and pressure, but must tolerate lower cleaning rate and purity. Embodiment 2 is suitable for production scenarios that require fast and efficient production, although the reaction conditions need to be strictly controlled to reduce the generation of by-products.

[0120] In order to explore the advantages of N-dodecyl methyl dipolyoxyethylene ether ammonium hydroxide, three comparative experiments were designed. The experimental group was based on the best three examples of the above five embodiments, namely, embodiment 2, embodiment 4 and embodiment 5. The control group did not use N-dodecyl methyl dipolyoxyethylene ether ammonium hydroxide as a raw material, and used other common nonionic or cationic surfactants as substitutes for the experiment.

[0121] Experimental design

[0122] Experiment 1: Cleaning efficiency comparison experiment

[0123] Objective: To compare the cleaning efficiency of (N-dodecyl methyl dimeroxyethylene ether ammonium hydroxide) and other nonionic surfactants.

[0124] Experimental Group:

[0125] The surfactants prepared in Example 2, Example 4 and Example 5 were used.

[0126] Control group:

[0127] Alkylphenol polyoxyethylene ether (APEO) was used as the raw material for the control group. This type of compound is a common non-ionic surfactant.

[0128] Alternative reaction steps: select alkylphenol polyoxyethylene ether instead of N-dodecyl methyl dimeroxyethylene ether ammonium hydroxide.

[0129] Experimental steps:

[0130] Apply standard kitchen grease (a mixture of fatty acids and vegetable oils) to the stainless steel plate and wait for it to cure.

[0131] The detergents were diluted to 1% concentration in the experimental group and the control group, respectively, and stirred at 25°C.

[0132] Use each set of cleaning agents to wipe the coated stainless steel plate for 5 minutes and record the cleaning rate.

[0133] Experimental data table:

[0134]

[0135]

[0136] Analysis: The cleaning rate of the experimental group was significantly higher than that of the control group, indicating that N-dodecylmethyl dipolyoxyethylene ether ammonium hydroxide has a stronger decontamination ability. This is because the efficiency of the combination of hydrophilic groups and lipophilic groups is higher and the surface activity is better.

[0137] Experiment 2: Comparative experiment on surface tension reduction ability

[0138] Objective: To test the ability of surfactants to reduce the surface tension of water and to verify the effect of N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide) on enhancing surface activity.

[0139] Experimental Group:

[0140] The surfactants prepared in Example 2, Example 4 and Example 5 were used.

[0141] Control group:

[0142] A quaternary ammonium salt cationic surfactant such as dodecyltrimethylammonium chloride (DTAC) was used as a control group raw material without undergoing an oxyethylation reaction.

[0143] Experimental steps:

[0144] The cleaning agent was prepared as a 0.5% concentration aqueous solution.

[0145] The surface tension of the aqueous solution was tested using a tensiometer, and the reduction in surface tension of each group was recorded.

[0146]

[0147]

[0148] Experimental data table:

[0149] Analysis: In the experimental group, the reduction in surface tension was greater than that in the control group. This indicates that N-dodecylmethyl dipolyoxyethylene ether ammonium hydroxide can more effectively reduce the surface tension of water, help emulsify and disperse oil stains, and improve cleaning efficiency.

[0150] Experiment 3: Comparative experiment on hard water resistance

[0151] Purpose: To compare the cleaning ability of surfactants in hard water environment and test the improvement of hard water resistance by N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide.

[0152] Experimental Group:

[0153] The surfactants prepared in Example 2, Example 4 and Example 5 were used.

[0154] Control group:

[0155] A cationic surfactant of the fatty amine type which does not undergo an oxyethylation reaction, such as didecyl dimethyl ammonium chloride (DDAC), is used.

[0156] Experimental steps:

[0157] A 500 ppm hard water solution was prepared and 1% concentration of the experimental and control detergents were added.

[0158] Apply kitchen grease to the tile surface, let it sit and then scrub with a detergent.

[0159] Test cleaning efficiency under hard water and record the results.

[0160] Experimental data table:

[0161]

[0162] Analysis: The cleaning rate of the experimental group in hard water environment was much higher than that of the control group, indicating that the oxyethylation reaction of dodecylamine and ethylene oxide significantly improved the hard water resistance of the surfactant and reduced the interference of metal ions in hard water on the performance of the surfactant.

[0163] Through the detailed analysis of the three experimental data tables, the advantages of N-dodecyl methyl dipolyoxyethylene ether ammonium hydroxide can be clearly reflected, especially in terms of cleaning efficiency, surface tension reduction ability and hard water resistance. Next, each experimental data will be analyzed item by item, focusing on comparing the differences between the experimental group and the control group.

[0164] Experiment 1: Comparative analysis of cleaning efficiency

[0165] analyze:

[0166] The cleaning rates of the experimental groups were between 92.7% and 93.2%, which were very close, indicating that N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide had a higher cleaning efficiency.

[0167] The cleaning rate of the control group (using alkylphenol polyoxyethylene ether) was significantly lower, ranging from 87.9% to 88.5%, significantly lagging behind the experimental group. This shows that although alkylphenol polyoxyethylene ether is also a common nonionic surfactant, it is not as good as N-dodecyl methyl dimeroxyethylene ether ammonium hydroxide in emulsifying and dispersing stubborn oil stains.

[0168] Conclusion: The hydrophilic and lipophilic groups of N-dodecylmethyl dipolyoxyethylene ether ammonium hydroxide have a higher efficiency of combining, and its strong alkalinity significantly enhances the combination and emulsification effect with oil stains, thereby improving the cleaning efficiency. This advantage is particularly prominent in the cleaning of stubborn dirt such as kitchen oil stains.

[0169] Experiment 2: Comparative analysis of surface tension reduction capabilities

[0170] analyze:

[0171] The experimental group showed a significant advantage in the reduction of surface tension, with values ​​ranging from 31.9 to 33.0 mN / m. This shows that N-dodecylmethyl dipolyoxyethylene ether ammonium hydroxide can significantly reduce the surface tension of water, thereby enhancing the wettability and permeability of water, which helps to accelerate the emulsification and removal of oil stains.

[0172] The surface tension reduction of the control group was significantly smaller, ranging from 27.5 to 28.0 mN / m. This reflects that common quaternary ammonium salt surfactants (such as DTAC) are not as good as oxyethylated surfactants in reducing surface tension.

[0173] Conclusion: N-dodecyl methyl dimeroxyethylene ether ammonium hydroxide can significantly improve the ability of surfactants to reduce surface tension, and the hydrophilic group and lipophilic group have a higher efficiency in combining, which can more effectively disperse oil stains in water. This makes the oxyethylated surfactant more suitable for cleaning stubborn dirt.

[0174] Experiment 3: Comparative analysis of hard water resistance

[0175] analyze:

[0176] The cleaning rate of the experimental group under hard water conditions remained between 89.8% and 91.0%, and the cleaning efficiency was hardly affected by the calcium and magnesium ions in hard water. This shows that N-dodecylmethyl dipolyoxyethylene ether ammonium hydroxide has good hard water resistance and can maintain high cleaning efficiency in hard water environments.

[0177] The cleaning rate of the control group was significantly lower, only 74.5% to 75.0%. This is because quaternary ammonium surfactants are easy to combine with calcium and magnesium ions in hard water to form insoluble precipitates, thereby reducing their surface activity and affecting the cleaning effect.

[0178] Conclusion: Due to its special amphoteric structure, N-dodecylmethyl dipolyoxyethylene ether ammonium hydroxide can still maintain a high cleaning ability in hard water environment, avoiding the interference of calcium and magnesium ions on the performance of detergents. This excellent hard water resistance makes the application of this type of surfactant in hard water environment more extensive and effective.

[0179] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a novel surfactant for cleaning kitchen grease, characterized in that: The following steps are involved: S1, selecting dodecylamine and ethylene oxide as raw materials and adding them into a reactor, adding a catalyst under anhydrous and oxygen-free conditions, and performing an oxyethylation addition reaction; S2, after the reaction is completed, the reaction is cooled, and a neutralizing agent is added until the reactants are neutral to obtain an intermediate dodecylamine dipolyoxyethylene ether; S3, adding dodecylamine dimeroxyethylene ether and methyl chloride into a reaction kettle, and then adding a medium solvent, and performing recrystallization after the reaction is completed to obtain N-dodecylmethyl dimeroxyethylene ether ammonium chloride; S4, adding N-dodecylmethyl dimeroxyethylene ether ammonium chloride and potassium hydroxide into anhydrous ethanol, and stirring at room temperature; S5. After the reaction is completed, filter out the precipitated potassium chloride solid, and then evaporate the solution at low temperature to obtain N-dodecylmethyl dimeroxyethylene ether ammonium hydroxide.

2. The method for preparing a novel surfactant for cleaning kitchen greasy dirt according to claim 1, characterized in that: The catalyst in S1 is an alkaline catalyst, which includes sodium hydroxide, potassium hydroxide and anhydrous sodium carbonate solid. The neutralizer in S2 is acetic acid, and after neutralization, a bleaching agent is added to improve the color of dodecylamine dipolyoxyethylene ether, and the bleaching agent is hydrogen peroxide.

3. The method for preparing a novel surfactant for cleaning kitchen grease according to claim 1, characterized in that: In S1, the reactor is a high-pressure stainless steel reactor to achieve anhydrous and oxygen-free conditions, and the reaction temperature is 140-160° C., the reaction pressure is 0.15-0.3 MPa, and the reaction time is 4-6 hours.

4. The method for preparing a novel surfactant for cleaning kitchen grease according to claim 2, characterized in that: The mass ratios of the dodecylamine, ethylene oxide, alkaline catalyst, acetic acid and hydrogen peroxide are 1:(3.9-4.1):(0.002-0.003):(0.16-0.18):(0.08-0.11) respectively.

5. The method for preparing a novel surfactant for cleaning kitchen grease according to claim 1, characterized in that: In the S3, the reaction temperature is 80-90° C., the reaction pressure is 0.3-0.5 MPa, and the reaction time is 1-2 h.

6. The method for preparing a novel surfactant for cleaning kitchen greasy dirt according to claim 5, characterized in that: In the S3, the medium solvent is petroleum ether, and the temperature is lowered after the reaction is completed to allow N-dodecylmethyl dimeroxyethylene ether ammonium chloride to recrystallize and precipitate.

7. The method for preparing a novel surfactant for cleaning kitchen greasy dirt according to claim 6, characterized in that: The mass ratios of the dodecylamine dimeroxyethylene ether, methyl chloride and solvent petroleum ether are (16.0-16.8):1:(9.2-9.7) respectively.

8. The method for preparing a novel surfactant for cleaning kitchen grease according to claim 1, characterized in that: The reaction temperature and pressure in S4 are normal temperature and pressure, and the reaction time is 0.5 to 1 h.

9. The method for preparing a novel surfactant for cleaning kitchen grease according to claim 1, characterized in that: The mass ratios of N-dodecylmethyl dimeroxyethylene ether ammonium chloride, potassium hydroxide and anhydrous ethanol in S4 are (15.2-16.2):1:(5.7-6.5) respectively.

10. The method for preparing a novel surfactant for cleaning kitchen grease according to claim 1, characterized in that: In S5, the filtering device is a vacuum filter, the pore size of the filter paper or filter membrane used is 0.45-1.0 μm, and after obtaining the filtrate, a low-temperature evaporation device is used, the evaporation temperature is 40-50° C., the vacuum degree is 0.08-0.09 MPa, and the evaporation time is 1-2 h.

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