Bio-based anionic surfactant as well as preparation method and application thereof

Abstract

The invention discloses a bio-based anionic surfactant as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out hydrolysis treatment on a protein source to obtain a hydrolyzed protein solution; and subjecting a hydrophobic plant extract and the hydrolyzed protein solution to a Michael reaction so as to prepare the bio-based anionic surfactant. Protein and natural plant extracts are used as raw materials, a 100% bio-based surfactant with ionic characteristics is successfully synthesized, the surface tension of the prepared bio-based anionic surfactant is as low as 27.6 mN / m, and the bio-based anionic surfactant is superior to SDS and most commercial surfactants; and the blank of the ionic bio-based surfactant in the surfactant industry at present is filled.

Description

Technical Field

[0001] The invention belongs to the technical field of surfactants, and specifically relates to a bio-based anionic surfactant and a preparation method and application thereof. Background Art

[0002] Surfactants are widely used in a variety of industries, including personal care, home care, agriculture, and industrial cleaning. The sustainability of surfactants has become a growing concern due to their potential negative impacts on the environment and human health. The main issues with surfactants are their biodegradability and toxicity. Synthetic surfactants are generally not easily biodegradable in the environment, which can lead to the accumulation of surfactants in the environment over the long term, which may have adverse effects on wildlife and ecosystems. Although some surfactants can be biodegraded, they produce harmful byproducts that may be more toxic than the original compounds. As a key ingredient in personal care and hygiene products, the potential impact of surfactants on human health is a big concern. Some surfactants have also been linked to endocrine disruption in the human body, which may have serious long-term effects on human health.

[0003] Patent CN106540632A discloses a method of preparing a protein-based surfactant by using alkyl glycidyl ether, gelatin, and alkaline amino acids as raw materials, triethanolamine as a reaction solvent and alkaline catalyst, and a nucleophilic substitution reaction between collagen polypeptide and epoxy glycidyl ether under suitable conditions. Alkyl glycidyl ether and triethanolamine are both toxic, and cannot be completely removed from the final product in the method disclosed in the patent, which ultimately leads to adverse consequences for health, safety and the environment when using these products; Patent CN103194498A discloses a method for enzymatic synthesis of lauroyl collagen amino acid triethanolamine, using commercially available collagen powder as raw material, and obtaining the final product through enzymatic hydrolysis and filtration, concentration and drying, esterification reaction, filtration and dilution; However, in order to remove lipase and starch-based acrylic acid absorbent resin in the reaction system, this method requires dilution and filtration after the reaction, and the use cost of lipase is high. So far, non-ionic bio-based surfactants have made significant progress. There are still some challenges in the development of high-performance ionic bio-based surfactants. In practice, the combination of nonionic surfactants and ionic surfactants provides more effective performance in applications. Bio-based ionic surfactants, such as fatty acid-based surfactants and amino acid-based surfactants, are widely used in many fields. However, the performance of these surfactants may not be sufficient, and some of them are expensive in many applications. Therefore, low-cost, high-performance bio-based ionic surfactants are urgently needed to replace petrochemical surfactants, and efficient and cost-effective production methods are also urgently needed. Summary of the invention

[0004] The main purpose of the present invention is to provide a bio-based anionic surfactant and a preparation method and application thereof, so as to overcome the deficiencies of the prior art.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0006] An embodiment of the present invention provides a method for preparing a bio-based anionic surfactant, which comprises:

[0007] hydrolyzing the protein source to obtain a hydrolyzed protein solution;

[0008] and causing the hydrophobic plant extract to undergo Michael reaction with the hydrolyzed protein solution to prepare a bio-based anionic surfactant.

[0009] The embodiment of the present invention also provides a bio-based anionic surfactant prepared by the aforementioned preparation method.

[0010] The embodiments of the present invention also provide the use of the aforementioned bio-based anionic surfactant in the fields of personal care, household care, agricultural cleaning or industrial cleaning.

[0011] The embodiment of the present invention further provides a cleaning composition, which at least includes the aforementioned bio-based anionic surfactant.

[0012] The embodiment of the present invention further provides a bio-based reversible material, which includes the aforementioned bio-based anionic surfactant.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The present invention uses proteins and natural plant extracts as raw materials to successfully synthesize a class of 100% bio-based surfactants with ionic properties. The surface tension of the prepared bio-based anionic surfactant is as low as 27.6 mN / m, which is better than SDS and most commercial surfactants, filling the gap in the current ionic bio-based surfactants in the surfactant industry;

[0015] (2) The preparation method of the bio-based anionic surfactant provided by the present invention is carried out at room temperature and in aqueous solution, the conditions are simple, and it is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 is a schematic diagram of a method for preparing a bio-based anionic surfactant in a typical embodiment of the present invention;

[0018] Figure 2 is a mechanism diagram of the Michael addition reaction between aldehydes and proteins in a typical embodiment of the present invention;

[0019] Figure 3 is a graph of molecular weights of egg white before and after hydrolysis in Example 1 of the present invention;

[0020] Figure 4 is a graph showing the concentration and surface tension of the bio-based anionic surfactant prepared in Example 2 of the present invention;

[0021] Figure 5 is a surface tension diagram of the bio-based anionic surfactant and the surfactant sodium dodecyl sulfate (SDS) prepared in Example 2 of the present invention;

[0022] Figure 6 is a surface tension diagram of the bio-based anionic surfactant prepared in Example 3 of the present invention;

[0023] Figure 7 It is the surface tension diagram of the surfactant produced by the protein hydrolyzed for 1 day and 4 days in Example 3 of the present invention. DETAILED DESCRIPTION

[0024] In view of the defects of the prior art, the inventors of this case have proposed the technical solution of the present invention after long-term research and extensive practice. The present invention uses protein and natural plant extracts octanal and decanal as raw materials to successfully synthesize a class of 100% bio-based surfactants with ionic properties. The synthesis process is carried out at room temperature and aqueous solution. The surface tension of the prepared surfactant is as low as 27.6mN / m, which is better than SDS and most commercial surfactants. The research invention of the present invention fills the current gap in ionic bio-based surfactants in surfactant research and industry.

[0025] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0026] First of all, it should be noted that the definitions of the terms mentioned in the specification of the present invention are known to those skilled in the art. For example, the definitions of some of the terms are as follows:

[0027] Surfactant: Surfactant refers to a substance that can significantly reduce the surface tension of the target solution. It has fixed hydrophilic and lipophilic groups and can be arranged in a directional manner on the surface of the solution.

[0028] The molecular structure of surfactants is amphiphilic: one end is a hydrophilic group, and the other end is a hydrophobic group.

[0029] Surfactants are divided into ionic surfactants (including cationic and anionic surfactants), nonionic surfactants, amphoteric surfactants, compound surfactants, and other surfactants.

[0030] Specifically, as one aspect of the technical solution of the present invention, a method for preparing a bio-based anionic surfactant includes:

[0031] hydrolyzing the protein source to obtain a hydrolyzed protein solution;

[0032] and causing the hydrophobic plant extract to react with the hydrolyzed protein solution to produce a bio-based anionic surfactant.

[0033] In some preferred embodiments, the preparation process of the bio-based anionic surfactant in the present invention is as follows Figure 1 The process shown includes two steps: the first step is to hydrolyze the protein, because the raw protein usually has a high molecular weight, which limits its water solubility and hydrophilicity. By decomposing the molecular weight, its performance can be significantly improved; the second step is to use the Michael reaction to bind plant aldehyde compounds to proteins, which is a commonly used method in protein modification. The obtained surfactant will be compared with commercial surfactants.

[0034] Surfactants contain both hydrophilic and hydrophobic parts in one molecule. Among all bio-based materials, protein is a good hydrophilic (water-soluble) compound and a good candidate for preparing bio-based ionic surfactants. Its hydrophilicity can be adjusted by hydrolysis as needed. By attaching hydrophobic plant extracts to proteins, 100% bio-based ionic surfactants can be synthesized. Through the evaluation of protein reactivity, natural aldehyde compounds were selected as hydrophobic structures because they react with protein amino groups through Michael addition reactions. Under certain conditions, the reaction is reversible in water. Therefore, it is possible to obtain 100% bio-based reversible surfactants using this system, as follows Figure 2 shown.

[0035] In some preferred embodiments, the protein source can be any water-soluble protein source.

[0036] Furthermore, the water-soluble protein source includes any one or more combinations of egg white, soy protein, and gelatin, but is not limited thereto.

[0037] Furthermore, the protein source may be of any molecular weight, and the smaller the molecular weight, the stronger the water solubility and hydrolyzability.

[0038] Furthermore, the molecular weight of the protein source is less than 10,000; further, the molecular weight of the protein source is less than 1,000.

[0039] In some preferred embodiments, the protein source can be any hydrolyzed biological protein including egg white, but is not limited thereto.

[0040] In some preferred embodiments, the molecular weight of the protein in the hydrolyzed protein solution can be any value, including a single amino acid.

[0041] In some preferred embodiments, the hydrophobic plant extract is a natural aldehyde compound.

[0042] Furthermore, the natural aldehyde compound includes octanal and / or decanal, but is not limited thereto.

[0043] Furthermore, the natural aldehyde compound is preferably octanal.

[0044] In some preferred embodiments, the preparation method specifically comprises: mixing an alkaline solution or an acidic solution with a protein source and performing a hydrolysis treatment at room temperature, and then adjusting the pH value of the obtained solution to 7-8 to obtain a hydrolyzed protein solution.

[0045] Furthermore, the pH value of the obtained solution is adjusted in order to ensure biocompatibility.

[0046] Furthermore, the alkaline substance in the alkaline solution may be any non-toxic alkaline substance, and may be sodium hydroxide.

[0047] Furthermore, the content of the alkaline substance in the alkaline solution is 0.1 to 50 wt %.

[0048] Furthermore, the content of the alkaline substance in the alkaline solution is 1.0 to 20.0 wt %.

[0049] Furthermore, the content of the alkaline substance in the alkaline solution is 5.0-12.0 wt %.

[0050] Furthermore, the content of the alkaline substance in the alkaline solution is 10 wt %.

[0051] Furthermore, the mass ratio of the protein source to the alkaline solution is 1-99:90-10.

[0052] Furthermore, the hydrolysis treatment time is 0.5 to 30 days.

[0053] Furthermore, the hydrolysis treatment time is 1 to 4 days.

[0054] Furthermore, an acidic substance is used to adjust the pH value of the obtained solution.

[0055] Further, the acidic substance includes an organic acid and / or an inorganic acid, and the inorganic acid includes sulfuric acid and / or hydrochloric acid, but is not limited thereto.

[0056] In some preferred embodiments, the preparation method specifically includes: using an alkaline substance to adjust the pH value of the hydrolyzed protein solution to 9-12, then adding a hydrophobic plant extract and performing a Michael reaction at room temperature, and then adjusting the pH value of the obtained solution to 7-8 to obtain the bio-based anionic surfactant.

[0057] In some preferred embodiments, the preparation method specifically includes: using an alkaline substance to adjust the pH value of the hydrolyzed protein solution to 10-11, then adding a hydrophobic plant extract and performing a Michael reaction at room temperature, and then adjusting the pH value of the obtained solution to 7-8 to obtain the bio-based anionic surfactant.

[0058] In some preferred embodiments, the preparation method specifically includes: using an alkaline substance to adjust the pH value of the hydrolyzed protein solution to 11, then adding a hydrophobic plant extract and performing a Michael reaction at room temperature, and then adjusting the pH value of the obtained solution to 7-8 to obtain the bio-based anionic surfactant.

[0059] Furthermore, the mass ratio of the protein in the hydrolyzed protein solution to the hydrophobic plant extract is 1:1-0.005.

[0060] Furthermore, the mass ratio of the protein in the hydrolyzed protein solution to the hydrophobic plant extract is 1:0.2-0.02.

[0061] Furthermore, the Michael reaction time is more than 1 min.

[0062] Furthermore, the Michael reaction time is 24 hours.

[0063] In some more specific embodiments, the method for preparing the bio-based anionic surfactant comprises:

[0064] (1) 100 g of pure egg white was mixed with 100 g of 10% sodium hydroxide aqueous solution and stirred at room temperature for 1 day and 4 days. The resulting solution was neutralized with 60% sulfuric acid and the pH was adjusted to 7-8 to obtain a hydrolyzed protein solution. The protein content of the final solution was calculated to be about 4.77%.

[0065] (2) 20 grams of the hydrolyzed protein solution was placed in a container, and 4 drops of 45% sodium hydroxide aqueous solution were added to adjust the pH value of the solution to about 11. Different amounts of plant extracts (octanal or decanal) were added to the solution and mixed, and stirred at room temperature for about 24 hours using a magnetic stirrer. After stirring, the pH value was adjusted to 7-8 using a 60% sulfuric acid neutralization solution to obtain a bio-based anionic surfactant solution.

[0066] Another aspect of the embodiments of the present invention further provides a bio-based anionic surfactant prepared by the aforementioned preparation method.

[0067] Another aspect of the embodiments of the present invention further provides the use of the aforementioned bio-based anionic surfactant in the fields of personal care, household care, agricultural cleaning or industrial cleaning.

[0068] Another aspect of an embodiment of the present invention further provides a cleaning composition, which at least includes the aforementioned bio-based anionic surfactant.

[0069] Another aspect of the embodiments of the present invention further provides a bio-based reversible material, which includes the aforementioned bio-based anionic surfactant.

[0070] The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments and drawings. This embodiment is implemented on the premise of the technical solution of the invention, and a detailed implementation method and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0071] The experimental materials used in the following examples, unless otherwise specified, can all be purchased from conventional biochemical reagent companies. For example, the eggs used below were purchased from Costco, sodium hydroxide, sulfuric acid, octanal and decanal were purchased from Sigma-Aldrich, and distilled water was purchased from Kroger.

[0072] In the present invention, the molecular weight is measured using an Agilent 1260 Infinite II GPC system; the transmittance is measured using a Konica Minolta spectrophotometer CM-5 with water as a reference; and the surface tension is characterized using a contact angle system OCA from Dataphysics.

[0073] Example 1

[0074] 100 g of pure egg white was mixed with 100 g of 10% sodium hydroxide aqueous solution, stirred at room temperature for 1 day and 4 days, and the resulting solution was neutralized with 60% sulfuric acid to adjust the pH to 7-8 to obtain a hydrolyzed protein solution. The protein content of the final solution was calculated to be about 4.77%.

[0075] The molecular weight of the egg white was measured before and after hydrolysis. Figure 3 As shown, the protein has 4 narrow peaks from GPC, which is used to determine the molecular weight of the polymer. After hydrolysis, the peaks become broad and many new peaks are generated, indicating that the high molecular weight part of the protein has been broken into smaller fragments, which is ideal.

[0076] Example 2

[0077] 100 g of pure egg white was mixed with 100 g of 10% sodium hydroxide aqueous solution, stirred at room temperature for 1 day and 4 days, and the obtained solution was neutralized with 60% sulfuric acid to adjust the pH to 7-8 to obtain a hydrolyzed protein solution. It was calculated that the protein content of the final solution was about 4.77%.

[0078] (2) 20 g of protein solution was placed in a container, and 4 drops of 45% sodium hydroxide aqueous solution were added to adjust the pH value of the solution to about 11. Different amounts of octanal were added to the solution and mixed, and stirred at room temperature for about 24 hours using a magnetic stirrer. After stirring, the pH value was adjusted to 7-8 using a 60% sulfuric acid neutralization solution to obtain a bio-based anionic surfactant solution.

[0079] Among them, pure egg white was hydrolyzed for 4 days, 20g of hydrolyzed protein solution (1g of protein) was reacted with 0.1g of octanal, and the concentration and surface tension curve of the prepared bio-based anionic surfactant was as follows: Figure 4 As shown, the surface tension is as low as 32mN / m, which is comparable to most commercial surfactants; unlike traditional small molecule surfactants, the surface tension continues to decrease after the critical micelle concentration (CMC). This may be caused by the molecular structure of the surfactant. Since CMC is a mixture of surfactants with various molecular weights, some of which have a higher molecular weight, the formation of CMC may not be as rapid and uniform as that of small molecule surfactants.

[0080] CMC is an important characteristic of surfactant efficiency. When CMC is low, it indicates that the surfactant is efficient. The applicant in this case determined the CMC of protein / octanal surfactants and compared it with SDS. The results are shown in Table 1. The CMC of these surfactants is only a small fraction of SDS.

[0081] Table 1 CMC and SDS of protein / octanal surfactants

[0082] Content of Octanal,g SDS 0.03 0.05 0.10 CMC, mg / L 2000 5.5 3.1 9.5

[0083] Among them, 0.03, 0.05, and 0.10 in Table 1 represent the amount of octanal corresponding to 1g of protein.

[0084] In addition, pure egg white was hydrolyzed for 4 days, and 20 g of the hydrolyzed protein solution (1 g of protein) was reacted with different amounts of octanal to prepare the bio-based anionic surfactant and the surfactant sodium dodecyl sulfate (SDS) with a surface tension of Figure 5 As shown, it can be seen that the bio-based anionic surfactant prepared by the reaction of protein and octanal has comparable or better performance than SDS, especially when the mass ratio of protein to octanal is 1:0.05, its surface tension is more than 5mN / m lower than that of SDS.

[0085] Example 3

[0086] (1) 100 g of pure egg white was mixed with 100 g of 10% sodium hydroxide aqueous solution, and stirred at room temperature for 1 day and 4 days. The resulting solution was neutralized with 60% sulfuric acid to adjust the pH to 7-8 to obtain a hydrolyzed protein solution. The protein content of the final solution was calculated to be about 4.77%.

[0087] (2) 20 grams of protein solution was placed in a container, and 4 drops of 45% sodium hydroxide aqueous solution were added to adjust the pH value of the solution to about 11. Different amounts of decanal were added to the solution and mixed, and stirred at room temperature for about 24 hours using a magnetic stirrer. After stirring, the pH value was adjusted to 7-8 using a 60% sulfuric acid neutralization solution to obtain a bio-based anionic surfactant solution.

[0088] Among them, pure egg white was hydrolyzed for 4 days, and when 20g of hydrolyzed protein solution (1g of protein) reacted with different amounts of decanal, the surface tension of the prepared bio-based anionic surfactant was as follows: Figure 6 shown.

[0089] In addition, the surface tension of the surfactant produced by the proteins hydrolyzed for 1 day and 4 days was analyzed, e.g. Figure 7 As shown, it is clear that the surfactant made with protein hydrolyzed for 4 days has better performance. Based on this result, it can be seen that further hydrolysis of protein is needed to obtain surfactants with better performance.

[0090] The inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0091] It should be understood that the technical solution of the present invention is not limited to the above-mentioned specific implementation cases. Any technical deformation made according to the technical solution of the present invention without departing from the scope of protection of the purpose of the present invention and the claims shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a bio-based anionic surfactant, characterized in that: include: hydrolyzing the protein source to obtain a hydrolyzed protein solution; and causing the hydrophobic plant extract to undergo Michael reaction with the hydrolyzed protein solution to prepare a bio-based anionic surfactant.

2. The preparation method according to claim 1, characterized in that: The protein source includes a water-soluble protein source; preferably, the water-soluble protein source includes any one or more combinations of egg white, soy protein, and gelatin; preferably, the molecular weight of the protein source is less than 10,000; particularly preferably, the molecular weight of the protein source is less than 1,000; And / or, the hydrophobic plant extract is a natural aldehyde compound; preferably, the natural aldehyde compound includes octanal and / or decanal, preferably octanal.

3. The preparation method according to claim 1, characterized in that: Specifically include: The alkaline solution or acidic solution is mixed with the protein source and subjected to a hydrolysis treatment at room temperature, and then the pH value of the obtained solution is adjusted to 7-8 to obtain a hydrolyzed protein solution.

4. The preparation method according to claim 3, characterized in that: The alkaline substance in the alkaline solution includes sodium hydroxide; preferably, the content of the alkaline substance in the alkaline solution is 0.1 to 50 wt%, 1.0 to 20.0 wt%, and more preferably 5.0 to 12.0 wt%; and / or, the mass ratio of the protein source to the alkaline solution is 1-99:90-10; And / or, the hydrolysis treatment time is 0.5 to 30 days, preferably 1 to 4 days; And / or, an acidic substance is used to adjust the pH value of the obtained solution; preferably, the acidic substance includes an organic acid and / or an inorganic acid, wherein the inorganic acid includes sulfuric acid and / or hydrochloric acid.

5. The preparation method according to claim 1, characterized in that: Specifically include: The pH value of the hydrolyzed protein solution is adjusted to 9-12 by using an alkaline substance, and then a hydrophobic plant extract is added to carry out a Michael reaction at room temperature, and then the pH value of the obtained solution is adjusted to 7-8 to prepare the bio-based anionic surfactant; Preferably, the pH value of the protein hydrolyzate solution is adjusted to 10-11 using an alkaline substance.

6. The preparation method according to claim 5, characterized in that: The mass ratio of the protein in the hydrolyzed protein solution to the hydrophobic plant extract is 1:1 to 0.005; preferably 1:0.2 to 0.02; And / or, the Michael reaction time is more than 1 min.

7. A bio-based anionic surfactant prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the bio-based anionic surfactant according to claim 7 in the fields of personal care, household care, agricultural cleaning or industrial cleaning.

9. A cleaning composition, characterized in that At least comprising the bio-based anionic surfactant according to claim 7.

10. A bio-based reversible material, characterized in that: The invention comprises the bio-based anionic surfactant as claimed in claim 7.

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