Preparation method and application of bio-based nonionic surfactant

Abstract

The invention provides a preparation method and application of a bio-based nonionic surfactant, which comprises the following steps: synthesizing an intermediate through reaction of linear or branched alkyl primary amine and itaconic acid, and then reacting with polyethylene glycol to synthesize the bio-based nonionic surfactant. The non-ionic surfactant provided by the invention has low foam and excellent decontamination and washing effects, and can realize the effects of brightness and no water stain after tableware is washed.

Description

Technical Field

[0001] This invention relates to the field of surfactant technology, specifically to a method for preparing and applying a bio-based nonionic surfactant. Background Technology

[0002] Traditional petroleum-based surfactants are difficult to degrade, harming the environment, and in many scenarios, excessive foam production can hinder their application. For example, in dishwashing and laundry, excessive foam can damage the dishwasher's water pump, and too much foam increases the amount of rinsing water, making it uneconomical and environmentally unfriendly. To obtain biodegradable, low-foaming surfactants, researchers have begun to study the preparation of surfactants using bio-based materials. For instance, Chinese patent application CN119751548A describes a bio-based surfactant, its preparation method, and its application. This application uses disproportionated rosin as a raw material, reacting it with a dipeptide amino acid to obtain a bio-based surfactant. This surfactant is then mixed with choline chloride in a specific ratio to obtain a stable, environmentally friendly carbon nanotube dispersion. Another example is Chinese patent application CN119685038A, which describes an oligomeric bio-based surfactant, its preparation method, and its application. This application provides an oligomeric bio-based surfactant with a branched spatial structure, exhibiting stronger stripping ability against the oil phase. When used to clean oily soil, it provides excellent cleaning results with minimal foaming, reducing the difficulty of subsequent rinsing. Surfactants used in dishwashing and laundry applications also need to have good detergency. Therefore, it is necessary to develop a low-foaming, high-efficiency detergency surfactant with good compatibility to adapt to the green, efficient, and energy-saving development trend of dishwashing and laundry. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a bio-based nonionic surfactant and the intermediate thereof, so that the prepared surfactant has high cleaning effect while also having the characteristics of low foam and green environmental protection.

[0004] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a bio-based nonionic surfactant having the following Formula I structure: Formula I R1 is a C8~C18 straight-chain or branched alkyl group, and n=5~250.

[0005] In a second aspect, the present invention provides a method for preparing the above-mentioned bio-based nonionic surfactant, the method comprising the following steps: S1. Itaconic acid and straight-chain or branched alkyl primary amines are added in proportion to react and the compound of formula II is obtained: Formula II S2. React compound II with polyethylene glycol in the presence of a catalyst to obtain compound I: Formula I R1 is a C8~C18 straight-chain or branched alkyl group, and n=5~250.

[0006] In the above methods, the straight-chain or branched alkyl primary amine is selected from at least one of octylamine, decylamine, laurylamine, myristicamine, palmitamine, stearylamine, and cocoylamine.

[0007] Preferably, in step S1, the molar ratio of the straight-chain or branched alkyl primary amine to itaconic acid is 0.5-3:1.

[0008] Preferably, the reaction conditions for step S1 are as follows: the reactants are heated and refluxed under an inert atmosphere for a period of time to obtain compound II.

[0009] Furthermore, the inert atmosphere is nitrogen, the heating temperature is 50~180℃, and the heating time is 1-10h.

[0010] In the above method, the polyethylene glycol is selected from at least one of polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 800, polyethylene glycol 1000, polyethylene glycol 2000, polyethylene glycol 4000, polyethylene glycol 6000, polyethylene glycol 8000, and polyethylene glycol 10000.

[0011] Preferably, in step S2, the molar ratio of polyethylene glycol to compound of formula II is 0.5-3:1.

[0012] Preferably, the reaction conditions for step S2 are as follows: while hot, polyethylene glycol and a catalyst are added to the compound of formula II obtained in step S1, stirred and heated to a specific temperature, and the reaction is carried out under vacuum for a period of time to remove moisture, so that the acid value is <20 mgKOH / g, thereby obtaining the compound of formula I.

[0013] Furthermore, the reaction system is heated to 100~200℃, and the reaction time is 1-10h.

[0014] Preferably, the catalyst used in step S2 is p-toluenesulfonic acid, concentrated sulfuric acid, phosphoric acid, or SO4. 2- / ZrO2 solid superacid, stannous chloride, tin oxide, titanium alkoxide salt or at least one of these.

[0015] More preferably, the amount of catalyst added is 0.1%-10% of the total mass of the reactants.

[0016] In a third aspect, the present invention provides the use of the bio-based nonionic surfactant as described above for the manufacture of dishwashing powder or laundry detergent.

[0017] In a fourth aspect, the present invention provides an intermediate compound having the following structure: Formula II R1 is a C8~C18 straight-chain or branched alkyl group.

[0018] In a fifth aspect, the present invention provides a method for preparing the intermediate compound described above, the method comprising the following steps: feeding itaconic acid and a straight-chain or branched alkyl primary amine in a proportion, and reacting to obtain a compound of formula II: Formula II R1 is a C8~C18 straight-chain or branched alkyl group.

[0019] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention provides a method for preparing and applying a bio-based nonionic surfactant. An intermediate is synthesized through the reaction of a linear or branched alkyl primary amine with itaconic acid, and then reacted with polyethylene glycol to synthesize the bio-based nonionic surfactant of this invention. The nonionic surfactant provided by this invention has low foaming and excellent detergency and washing effects, achieving a bright and water-stain-free finish on tableware after washing. Attached Figure Description

[0020] Figure 1 The infrared spectrum of the bio-based nonionic surfactant synthesized using the method in Example 4 of this invention; Figure 2 These are photos showing the effect of the bio-based nonionic surfactant synthesized using the method in Example 6 of this invention on cleaning glass cups; Figure 3 This is a sample photograph of the compound from Example 6 of the present invention. Detailed Implementation

[0021] This invention discloses a bio-based nonionic surfactant and its preparation method, comprising the following steps: S1, mixing itaconic acid with a linear or branched alkyl primary amine at a certain molar ratio, introducing nitrogen gas, and heating to a specific temperature to carry out the reaction, such that the residual itaconic acid content is <1wt%, to obtain a bio-based intermediate; S2, mixing the bio-based intermediate, polyethylene glycol, and a catalyst, heating, and carrying out an esterification reaction under vacuum, such that the acid value of the mixture is <25mg KOH / g, thereby obtaining the nonionic surfactant. The nonionic surfactant prepared by this invention has excellent dishwashing performance, low foaming, minimal water stains, and is environmentally friendly.

[0022] The preparation method of the bio-based nonionic surfactant of the present invention includes the following steps: S1. Itaconic acid and linear or branched alkyl primary amines are added in a certain proportion, nitrogen gas is introduced, and the mixture is heated and kept under reflux for a period of time to obtain a bio-based intermediate. The bio-based intermediate has the following structure: Formula II Formula II S2. While still hot, add polyethylene glycol and catalyst to the intermediate, stir and heat to a specific temperature, react under vacuum for a period of time, remove moisture, and make the acid value <20mg KOH / g, thus obtaining the nonionic surfactant of the present invention, which has the following structure: Formula I In the above structural formulas, R1 is a C8~C18 straight-chain or branched alkyl group, and n=5~250.

[0023] In the above methods, the straight-chain or branched alkyl primary amines include at least one of octylamine, decylamine, laurylamine, myristicamine, palmitamine, stearylamine, and cocoylamine.

[0024] In the above method, the molar ratio of the straight-chain or branched alkyl primary amine to itaconic acid is 0.5-3:1.

[0025] In step S1 of the above method, the heating temperature is 50~180℃ and the heating reflux time is 1-10h.

[0026] In the above methods, polyethylene glycol includes at least one of polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 800, polyethylene glycol 1000, polyethylene glycol 2000, polyethylene glycol 4000, polyethylene glycol 6000, polyethylene glycol 8000, and polyethylene glycol 10000.

[0027] In the above methods, the molar ratio of polyethylene glycol to bio-based intermediates is 0.5-3:1.

[0028] In step S2 of the above method, the heating temperature is 100~200℃ and the heating reaction time is 1-10h.

[0029] Similarly, in step S2 of the above method, the catalyst is p-toluenesulfonic acid, concentrated sulfuric acid, phosphoric acid, or SO4. 2- / ZrO2 solid superacid, stannous chloride, tin oxide, titanium alkoxide salt or at least one of these.

[0030] Furthermore, the amount of catalyst added is 0.1%-10% of the total mass of the reactants.

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicating orientation or positional relationships, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] It should be understood that the following embodiments are provided for the purpose of illustrating the present invention only, and do not represent all the various solutions within the scope of protection of the present invention. After understanding the principles of the present invention, those skilled in the art can easily implement various alternative solutions by referring to the following embodiments, and these alternative solutions should also be within the scope of protection of the present invention.

[0035] All reagents and reactants used in the following examples are conventional chemical raw materials that are commercially available, and will not be described in detail below.

[0036] Example 1 This embodiment provides a bio-based nonionic surfactant, the preparation method of which includes the following steps: S1. Add 130g itaconic acid and 129g octylamine to a four-necked flask, purge with nitrogen, and heat under reflux at 80°C for 4 hours to obtain a bio-based intermediate. S2. While still hot, add 1000g of polyethylene glycol 1000 and 3g of p-toluenesulfonic acid to a four-necked flask, heat to 180°C, and dehydrate under vacuum. Test the acid value every 30 minutes until the acid value is below 20mg KOH / g, then allow it to cool naturally to obtain the bio-based nonionic surfactant of this invention.

[0037] Example 2 This embodiment refers to Example 1 for the preparation of a bio-based nonionic surfactant. The difference between this embodiment and Example 1 is that 103g of octylamine is used in the preparation of the bio-based nonionic surfactant in this embodiment. Apart from the above difference, the materials and process operations used in this embodiment are strictly consistent with those in Example 1.

[0038] Example 3 This embodiment refers to Example 1 for the preparation of a bio-based nonionic surfactant. The difference between this embodiment and Example 1 is that 1200g of polyethylene glycol 1000 is used in the preparation of the bio-based nonionic surfactant in this embodiment. Apart from the above difference, the materials and process operations used in this embodiment are strictly consistent with those in Example 1.

[0039] Example 4 This embodiment refers to Example 1 for the preparation of a bio-based nonionic surfactant. The difference between this embodiment and Example 1 is that 800g of polyethylene glycol 800 is used in the preparation of the bio-based nonionic surfactant in this embodiment. Apart from the above difference, the materials and process operations used in this embodiment are strictly consistent with those in Example 1.

[0040] Example 5 This embodiment refers to Example 1 for the preparation of a bio-based nonionic surfactant. The difference between this embodiment and Example 1 is that the esterification catalyst used in this embodiment is 3g of concentrated sulfuric acid. Apart from the above difference, the materials and process operations used in this embodiment are strictly consistent with those in Example 1.

[0041] Example 6 This embodiment refers to Example 1 for the preparation of a bio-based nonionic surfactant. The difference between this embodiment and Example 1 is that the linear or branched alkyl primary amine used in this embodiment is stearyl amine, 270g. Apart from the above differences, the materials and process operations used in this embodiment are strictly consistent with those in Example 1.

[0042] Example 7 This embodiment refers to Example 1 for the preparation of a bio-based nonionic surfactant. The difference between this embodiment and Example 1 is that in the preparation of the bio-based nonionic surfactant, the linear or branched alkyl primary amine used in this embodiment is 200g of coconut oil amine, the polyethylene glycol used is 1000g of polyethylene glycol 4000, and the catalyst used is 3g of stannous chloride. Apart from the above differences, the materials and process operations used in this embodiment are strictly consistent with those in Example 1.

[0043] Example 8 This embodiment refers to Example 1 for the preparation of a bio-based nonionic surfactant. The difference between this embodiment and Example 1 is that in the preparation of the bio-based nonionic surfactant, the linear or branched alkyl primary amine used in this embodiment is 120g of myristamine, the polyethylene glycol is 3000g of polyethylene glycol 10000, and the catalyst is 2g of titanium tert-butoxide. Apart from the above differences, the materials and process operations used in this embodiment are strictly consistent with those in Example 1.

[0044] Example 9 This embodiment refers to Example 1 for the preparation of a bio-based nonionic surfactant. The difference between this embodiment and Example 1 is that in the preparation of the bio-based nonionic surfactant in this embodiment, the linear or branched alkyl primary amine used is 250g of palmitate and the polyethylene glycol is 1500g of polyethylene glycol 6000. Apart from the above differences, the materials and process operations used in this embodiment are strictly consistent with those in Example 1.

[0045] The synthesized compounds were characterized after synthesis. Figure 1 Taking Example 4 as an example, the synthesized bio-based surfactant was subjected to infrared spectroscopy testing, such as... Figure 1 As shown, the characteristic peak of this surfactant is 3427 cm⁻¹. -1 The broad peak at 1735 cm⁻¹ is due to the stretching of the -OH group in the hydroxyl group in the product. -1 1566cm -1 The absorption peak at 1065 cm⁻¹ represents the absorption peaks of the ester and carbonyl groups in the surfactant. -1 and 1119cm -1 The peak at that position is due to CO stretching absorption, which proves that the bio-based nonionic surfactant has been successfully prepared.

[0046] Taking Example 6 as an example, the washing effect of the bio-based nonionic surfactant in this example was tested.

[0047] 1. Glass washing test Dishwashing powder formula: 30g sodium citrate, 25g sodium carbonate, 15g sodium percarbonate, 4g TAED, 15g sodium sulfate, 3g polymer dispersant, 1g alkaline protease, 1g amylase, 5g bio-based nonionic surfactant.

[0048] Washing method: Light load mode (1 hour 10 minutes); Siemens IQ300.

[0049] Washing frequency: 5 times.

[0050] Dirt: margarine, milk powder, egg yolk.

[0051] Its washing effect is as follows Figure 1 As shown.

[0052] 2. Clothing washing test Concentrated laundry detergent formula: 0.5% EDTA-disodium, 1.5% trisodium citrate, 10% AES, 4% HP20, 4% anhydrous ethanol, 1% sodium chloride, 1% active compound enzyme, 1% 1,2-propanediol, 35% bio-based nonionic surfactant, water to 100%.

[0053] Washing conditions: water hardness 300 mg / kg.

[0054] Washing equipment: Vertical stain remover.

[0055] Soiled cloth: JB-01 / JB-02 / JB-03.

[0056] Implementation standard: GB / T13174-2021.

[0057] The washing effect is shown in Table 1.

[0058] Table 1. Whiteness values ​​of nonionic surfactants after washing three types of soiled cloths in Example 6. Figure 2 The washing results shown in Table 1 indicate that the bio-based nonionic surfactant of the present invention has a good effect on washing dishes and clothes. Glass cups are clear and bright, without dirt, water stains, spots, or film marks. The concentrated laundry detergent prepared has an excellent washing effect, especially on protein dirt and sebum.

[0059] Any aspects of this invention not described in detail are well-known to those skilled in the art.

[0060] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications and equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A bio-based nonionic surfactant, characterized in that, The surfactant has the following Formula I structure: Formula I R1 is a C8~C18 straight-chain or branched alkyl group, and n=5~250.

2. The method for preparing the bio-based nonionic surfactant as described in claim 1, characterized in that, The method includes the following steps: S1. Itaconic acid and straight-chain or branched alkyl primary amines are added in proportion to react and the compound of formula II is obtained: Formula II S2. React compound II with polyethylene glycol in the presence of a catalyst to obtain compound I: Formula I R1 is a C8~C18 straight-chain or branched alkyl group, and n=5~250.

3. The method as described in claim 2, characterized in that, The straight-chain or branched alkyl primary amine is selected from at least one of octylamine, decylamine, laurylamine, myristicamine, palmitamine, stearylamine, and cocoylamine.

4. The method as described in claim 2, characterized in that, In step S1, the molar ratio of the straight-chain or branched alkyl primary amine to itaconic acid is 0.5-3:

1.

5. The method as described in claim 2, characterized in that, The reaction conditions for step S1 are as follows: the reactants are heated and refluxed under an inert atmosphere for a period of time to obtain compound II.

6. The method as described in claim 5, characterized in that, The inert atmosphere is nitrogen, the heating temperature is 50~180℃, and the heating time is 1-10h.

7. The method as described in claim 2, characterized in that, The polyethylene glycol is selected from at least one of polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 800, polyethylene glycol 1000, polyethylene glycol 2000, polyethylene glycol 4000, polyethylene glycol 6000, polyethylene glycol 8000, and polyethylene glycol 10000.

8. The method as described in claim 2, characterized in that, In step S2, the molar ratio of polyethylene glycol to compound of formula II is 0.5-3:

1.

9. The method as described in claim 2, characterized in that, The reaction conditions for step S2 are as follows: while the compound of formula II obtained in step S1 is still hot, polyethylene glycol and a catalyst are added, the mixture is stirred and heated to a specific temperature, and the reaction is carried out under vacuum for a period of time to remove moisture, so that the acid value is <20 mg KOH / g, thus obtaining compound of formula I.

10. The method as described in claim 9, characterized in that, The reaction system is heated to 100~200℃, and the reaction time is 1-10h.

11. The method as described in claim 2, characterized in that, The catalyst used in step S2 is p-toluenesulfonic acid, concentrated sulfuric acid, phosphoric acid, and SO4. 2- / ZrO2 solid superacid, stannous chloride, tin oxide, titanium alkoxide salt or at least one of these.

12. The method as described in claim 11, characterized in that, The amount of catalyst added is 0.1%-10% of the total mass of the reactants.

13. Use of the bio-based nonionic surfactant as described in claim 1 or the bio-based nonionic surfactant prepared by any one of claims 2 to 12, for the manufacture of dishwashing powder or laundry detergent.

14. An intermediate compound, characterized in that, It has the following structure: Formula II R1 is a C8~C18 straight-chain or branched alkyl group.

15. The method for preparing the intermediate compound as described in claim 14, characterized in that, The method includes the following steps: feeding itaconic acid and a straight-chain or branched alkyl primary amine in a specific ratio, and reacting to obtain compound of formula II: Formula II R1 is a C8~C18 straight-chain or branched alkyl group.

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