CN115975184A - Cationic biopolymer and preparation method and application thereof - Google Patents

Abstract

The invention relates to a cationic biopolymer and a preparation method thereof, wherein the cationic biopolymer is a cationized poly acidic amino acid, and is formed by substituting hydrogen atoms of carboxyl groups in at least one part of side chains of the poly acidic amino acid by groups with quaternary ammonium cationic groups; the preparation method of the cationic biopolymer combines the cationization reagent with the side chain carboxyl of the polyacid amino acid stably through a covalent bond, has controllable degree of substitution, is easy to regulate and control the production and processing technology of hair washing and protecting products, and is beneficial to improving the quality of the hair washing and protecting products; in addition, the preparation method uses water as a solvent for homogeneous reaction, and is simple, efficient and environment-friendly. The invention also relates to a composition for hair care and washing. The composition takes the cationic biopolymer as a main active ingredient, has relatively excellent hair damage repairing and conditioning effects, and is beneficial to improving the quality of hair washing and protecting products.

Description

Cationic biopolymer and its preparation method and application

Technical Field

The invention belongs to the technical field of biomacromolecule modification and preparation, and relates to a cationic biopolymer and a preparation method and application thereof.

Background Art

The side chains of polyacidic amino acids (including aspartic acid, glutamic acid, etc. and polymers obtained from different configurations thereof) carry a large number of carboxyl groups and are excellent in water solubility. They not only have the physicochemical properties of general carboxyl polymers, but also have good biodegradability and biocompatibility. This makes them widely studied and applied in many fields such as agriculture, water treatment, daily chemicals, and medicine. Especially in the cosmetics industry, polyacidic amino acids and their salts are used as functional components such as humectants, thickeners, or stabilizers, and are applied to skin care products, shampoos, cleaning fluids, etc., and have excellent use characteristics.

However, due to the strong ionicity of polyacidic amino acids, it is necessary to pay close attention to the control of process conditions after adding them to water-oil mixed systems such as emulsions and creams, otherwise it will cause problems such as viscosity reduction and demulsification. In addition, since the side chain carboxyl groups of polyacidic amino acids form a large number of anions in the solution, their conditioning and repairing effects as cosmetic components are not as good as those of cationic compounds. Therefore, how to improve polyacidic amino acids into cationic polymers through chemical or physical methods is one of the research focuses of their scientific research and performance improvement.

Summary of the invention

The technical problem to be solved by the present invention is to provide a cationic biopolymer and a preparation method thereof in view of the above-mentioned deficiencies of the prior art. The cationic biopolymer prepared by the method stably combines the cationizing agent with the side chain carboxyl group of the polyacidic amino acid through a covalent bond, and the degree of substitution is controllable; the preparation process uses water as a solvent for homogeneous reaction, and the method is simple, efficient and environmentally friendly.

The present invention also provides a hair care composition, which has the above cationic biopolymer of the present invention as a main active ingredient, has relatively excellent hair damage repair and conditioning effects, and is beneficial to improving the quality of hair shampoo and hair care products.

To this end, the first aspect of the present invention provides a cationic biopolymer, which is a cationic acidic amino acid, wherein the cationic polyacidic amino acid is formed by replacing the hydrogen atoms of at least a part of the carboxyl groups in its side chain with a group having a quaternary ammonium cationic group, and its molecular structure is shown in formula (I):

In formula (I), A is a hydrogen atom or a substituent represented by the following formula (II) or formula (III); the average degree of substitution of the above substituents is 30 to 80%, m and n are positive integers representing the degree of polymerization and they represent only the number of polymerized monomer residues of two configurations, respectively, and the sum of m and n is 10 to 2500,

In formula (II) or (III), R1 represents an alkylene group having 1 to 2 carbon atoms, and R2, R3 and R4 each represent an alkyl group having 1 to 3 carbon atoms.

According to the present invention, the cationic biopolymer is obtained by reacting polyacidic amino acids with a cationizing agent, wherein the cationizing agent comprises one or more of the compounds having a molecular structure as shown in formula (IV):

In the formula (IV), R ₅ represents an alkylene group having 1 to 3 carbon atoms, R ₂ , R ₃ and R ₄ each represent an alkyl group having 1 to 3 carbon atoms, and X represents a halogen atom.

The second aspect of the present invention provides a method for preparing the cationic biopolymer according to the first aspect of the present invention, comprising the following steps:

S1, placing polysuccinimide in an alkaline aqueous solution, and obtaining a polyacidic amino acid salt aqueous solution by ring-opening hydrolysis reaction under stirring at room temperature;

S2, adjusting the pH value of the polyacidic amino acid salt aqueous solution to acidic with an aqueous solution of a water-soluble acid, then adding a cationizing agent, and performing a ring-opening esterification reaction to obtain a cationic biopolymer aqueous solution;

Step S3, after removing small molecular substances from the cationic biopolymer aqueous solution, drying is performed to obtain a white, light yellow or brownish yellow powdered cationic biopolymer.

According to the present invention, in step S1, the molecular weight of the polyacidic amino acid salt is 1 to 250 kDa; and/or the concentration of the polyacidic amino acid salt aqueous solution is 8 to 55 wt%.

Preferably, the alkaline aqueous solution is an aqueous solution of NaOH or KOH; preferably, the concentration of the alkaline aqueous solution is 1 to 10 mol/L.

In the present invention, the water-soluble acid includes one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and citric acid; preferably, the concentration of the aqueous solution of the water-soluble acid is 1 to 3 mol/L.

In some embodiments of the present invention, in step S2, the reaction conditions of the ring-opening esterification reaction include: pH value 4.20-4.90, reaction temperature 40-70° C., and reaction time 1-8 h.

In other embodiments of the present invention, in step S3, the method for removing small molecules from the cationic biopolymer aqueous solution is membrane filtration, and the drying method includes freeze drying and spray drying.

The third aspect of the present invention provides a composition for hair care, which contains the cationic biopolymer as described in the first aspect of the present invention or the cationic biopolymer prepared by the preparation method as described in the second aspect of the present invention, and the composition can repair and/or condition damaged hair.

In the present invention, the cationic biopolymer is a white, light yellow or brownish yellow powder, or a colorless, light yellow or brownish yellow aqueous solution.

In some embodiments of the present invention, the content of the cationic biopolymer in the composition is 20 wt % to 50 wt %.

According to the present invention, the composition further comprises water and a polyol.

In some embodiments of the present invention, the proportion of each component is 10-25 wt% of cationic biopolymer, 100 wt% of water Qsp and ≤50 wt% of polyol.

Preferably, the polyol includes one or more of ethylene glycol, propylene glycol, butylene glycol, hexylene glycol and glycerol.

According to the present invention, the composition further comprises cosmetically acceptable solvents, surfactants, foaming agents and other adjuvants.

The fourth aspect of the present invention provides use of the composition according to the third aspect of the present invention in preparing hair care products.

The fifth aspect of the present invention provides a hair care product comprising the composition according to the third aspect of the present invention.

The beneficial effects of the embodiments of the present invention are:

(1) The cationic biopolymer provided by the present invention provides a quaternary ammonium salt derivative of the cation and is covalently bonded to the side chain carboxyl of the polyacidic amino acid, which is effective and strong, is beneficial to the stability of the cosmetic formulation process and is easily absorbed by the hair as a cosmetic component, can improve the combing properties of the hair, and has a better repairing effect on the hair scales.

(2) The process for preparing the cationic biopolymer of the present invention has only one more step than the traditional polyacidic amino acid synthesis method, and does not require separation and purification of the intermediate product, so the operation is simple and easy. Moreover, the reaction is carried out under homogeneous conditions, and the substitution density of the product is uniform and the degree of substitution is controllable.

(3) The cationic biopolymer preparation process of the present invention uses water as solvent and is free of organic solvents. It is green, environmentally friendly, low-cost, and suitable for large-scale industrial production.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to make the present invention easy to understand, the present invention is described below with reference to the accompanying drawings.

FIG1 is a schematic flow diagram of a method for preparing a cationic biopolymer according to the present invention;

FIG2 is an IR spectrum of the cationic biopolymer obtained in Example 1;

FIG3 is the 1H-NMR spectrum of the cationic biopolymer obtained in Example 1;

FIG4 is a 13C-NMR spectrum of the cationic biopolymer obtained in Example 1;

FIG5 shows the hair combing performance test results;

FIG6 is a scanning electron micrograph of hair damage repair, wherein a is a blank control, b is a negative control, and c is a sample solution.

DETAILED DESCRIPTION

To make the present invention easy to understand, the present invention will be described in detail below. However, before describing the present invention in detail, it should be understood that the present invention is not limited to the specific embodiments described. It should also be understood that the terms used herein are only for describing specific embodiments and are not intended to be limiting.

Where a numerical range is provided, it is understood that each intervening value between the upper and lower limits of the range and any other specified or intervening values in the specified range is encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included in the smaller ranges and are also encompassed within the present invention, subject to any explicitly excluded limits in the specified ranges. Where a specified range includes one or two limits, ranges excluding either or both of those included limits are also encompassed within the present invention.

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

I. Terminology

The term "water" used in the present invention, unless otherwise specified, refers to deionized water, ultrapure water or distilled water.

The symbol "△" used in the present invention represents heating.

In the present invention, the terms "glycidyl trimethylammonium chloride", "glycidyl trimethylammonium chloride", "glycidyl trimethylammonium chloride", "glycidyl trimethylammonium chloride", "propylene oxide trimethylammonium chloride" and "propylene oxide trimethylammonium chloride" can be used interchangeably. Similarly, the terms "glycidyl triethylammonium chloride", "glycidyl triethylammonium chloride", "glycidyl triethylammonium chloride", "propylene oxide triethylammonium chloride" and "propylene oxide triethylammonium chloride" can also be used interchangeably. In addition, the term "glycidyl trimethylammonium chloride substituted polyaspartic acid" can also be expressed as "polyaspartic acid-3-hydroxy-3-trimethylammonium chloride propyl ester" according to the IUPAC organic nomenclature, and the term "glycidyl triethylammonium chloride substituted polyaspartic acid" can also be expressed as "polyaspartic acid-3-hydroxy-3-triethylammonium chloride propyl ester" according to the IUPAC organic nomenclature.

The term "water Qsp 100wt%" used in the present invention means that in a liquid mixture, in addition to the contents of the components listed or described, the rest is supplemented by water to 100%, that is, "the balance of water".

Any numerical value mentioned in the present invention includes all values that increase by one unit each time from the lowest value to the highest value if there is only an interval of two units between any minimum value and any maximum value. For example, if the amount of a component, or the value of a process variable such as temperature or time is stated to be 50 to 90, in this specification it means that 51 to 89, 52 to 88 ... and 69 to 71 and 70 to 71 are specifically listed. For non-integer values, 0.1, 0.01, 0.001 or 0.0001 can be appropriately considered as a unit. These are just some specially specified examples. In this application, in a similar manner, all possible combinations of numerical values between the listed lowest and highest values are considered to have been disclosed.

II. Implementation Plan

As mentioned above, due to the strong ionicity of polyacidic amino acids, it is necessary to pay great attention to the control of process conditions after adding them to water-oil mixed systems such as emulsions and creams, otherwise it will lead to problems such as viscosity reduction and demulsification of the mixed system. In addition, since the side chain carboxyl groups of polyacidic amino acids form a large number of anions in the solution, the conditioning and repairing effects of polyacidic amino acids as hair care cosmetic components are not as good as those of cationic compounds. Therefore, how to improve polyacidic amino acids into cationic polymers through chemical or physical methods is one of the research focuses of its scientific research and performance improvement. The present invention has conducted a lot of research on this.

The inventors have found that, in existing research reports, one of the methods for imparting cationic properties to polyacidic amino acids is to utilize the electrostatic interaction between the side chain carboxyl groups of polyacidic amino acids and cationic groups such as amino groups and quaternary ammonium salts, as well as the entangled structure of the polymer main chain, to combine the polyacidic amino acids with cationic compounds by physical adsorption. This method is simple and easy to implement, but the combination between the two is not strong, and the effect of improving the cosmetic formulation process and performance is not obvious.

Another method is to use polysuccinimide, a synthetic precursor of polyaspartic acid, as a raw material, and react it with amino, amino derivative or quaternary ammonium salt compounds in an organic solvent in a homogeneous or solvent-free state to obtain a partially open-ring polysuccinimide with amino, amino derivative or quaternary ammonium salt side chains, and then hydrolyze to obtain a cationic biopolymer. This method can obtain a stable cationic group-substituted polyaspartic acid with a controllable degree of substitution; however, the process conditions are relatively complex and harsh, and a large amount of organic solvent is required.

The present invention has further studied and found that a cationic biopolymer can be obtained by reacting a polyacidic amino acid with a cationizing agent. The cationic biopolymer is formed by replacing at least a portion of the hydrogen atoms of the carboxyl groups in the side chains of the polyacidic amino acid with a group having a quaternary ammonium cationic group, and its molecular structure is shown in formula (I):

In formula (I), A is a hydrogen atom or a substituent represented by the following formula (II) or formula (III); the average degree of substitution of the above substituents is 30-80%, preferably 40-55%, m and n are positive integers representing the degree of polymerization and they represent only the number of polymerized monomer residues of two configurations respectively and have nothing to do with whether the main chain is block, alternating or random polymerization, and the sum of m and n is 10-2500, preferably 100-500;

In formula (II) or (III), R1 represents an alkylene group having 1 to 2 carbon atoms, and R2, R3 and R4 each represent an alkyl group having 1 to 3 carbon atoms.

The cationizing agent includes one or more compounds having a molecular structure as shown in formula (IV):

In the formula (IV), R ₅ represents an alkylene group having 1 to 3 carbon atoms, R ₂ , R ₃ and R ₄ each represent an alkyl group having 1 to 3 carbon atoms, and X represents a halogen atom.

Those skilled in the art should understand that the so-called "the cationizing agent includes one or more of the compounds with a molecular structure as shown in formula (IV)" means that a cationic polyamino acid with a compound with a molecular structure as shown in formula (IV), or a mixture of two or more compounds with a molecular structure as shown in formula (IV) in any proportion can be reacted to obtain a cationic polyamino acid with a molecular structure as shown in formula (I).

The schematic diagram of the process flow of the method for preparing the cationic biopolymer involved in the present invention is shown in FIG1 . It can be seen that the method for preparing the cationic biopolymer specifically comprises the following steps:

S1, placing polysuccinimide in an alkaline aqueous solution, and obtaining a polyacidic amino acid salt aqueous solution by ring-opening hydrolysis reaction under stirring at room temperature;

S2, adjusting the pH value of the polyacidic amino acid salt aqueous solution to acidic with an aqueous solution of a water-soluble acid, then adding a cationizing agent having a molecular structure as shown in formula (IV), and performing a ring-opening esterification reaction to obtain a cationic biopolymer aqueous solution;

S3, after removing small molecules from the cationic biopolymer aqueous solution, drying is performed to obtain a white, light yellow or brownish yellow powdered cationic biopolymer.

In the preparation process of the above cationic biopolymer:

In step S1, the molecular weight of the polyacidic amino acid salt is 1-250 kDa, preferably 10-50 kDa; and/or the concentration of the polyacidic amino acid salt aqueous solution is 8-55 wt%, preferably 20-35 wt%.

Preferably, the alkaline aqueous solution is an aqueous solution of NaOH or KOH; preferably, the concentration of the alkaline aqueous solution is 1 to 10 mol/L, more preferably 1 to 3 mol/L.

In the present invention, the water-soluble acid is one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and citric acid; preferably, the concentration of the aqueous solution of the water-soluble acid is 1 to 3 mol/L, more preferably 1 to 1.5 mol/L.

In S2, the cationizing agent includes a compound having a structure represented by the general formula (IV), or a mixture of two or more compounds having a structure represented by the general formula (IV) in any proportion.

In the formula, R5 represents an alkylene group having 1 to 3 carbon atoms, R2, R3 and R4 represent alkyl groups having 1 to 3 carbon atoms respectively, and X represents a halogen atom;

Examples of suitable cationizing agents that conform to the general formula (IV) include glycidyl trialkyl ammonium halides, and specific examples include glycidyl trimethyl ammonium chloride, glycidyl triethyl ammonium chloride, and the like.

In step S2, the reaction conditions of the ring-opening esterification reaction include: pH value 4.20-4.90, preferably 4.40-4.60; reaction temperature 40-70°C, preferably 45-60°C; reaction time 1-8h, preferably 4-6h.

In step S3, the method for removing small molecules from the cationic biopolymer aqueous solution is membrane filtration, specifically, nanofiltration and ultrafiltration; the drying method includes freeze drying and spray drying.

The research results show that the method of the present invention is used to prepare cationic biopolymers, which stably combines the cationizing agent with the side chain carboxyl group of the polyacidic amino acid through covalent bonds, and the degree of substitution is controllable; the preparation process uses water as a solvent for homogeneous reaction, and the method is simple, efficient and environmentally friendly.

The present inventors have further studied and found that, compared with anionic polymers represented by polyacidic amino acids, the composition for hair care using the cationic polyacidic amino acids as the main active ingredient has better conditioning and repairing effects.

Therefore, the third aspect of the present invention provides a composition for hair care, which contains the cationic biopolymer as described in the first aspect of the present invention or the cationic biopolymer prepared by the preparation method as described in the second aspect of the present invention, and the composition can repair and/or condition damaged hair.

In the present invention, the cationic biopolymer is a white, light yellow or brownish yellow powder, or a colorless, light yellow or brownish yellow aqueous solution.

In some embodiments of the present invention, the content of the cationic biopolymer in the composition is 20 wt % to 50 wt %.

According to the present invention, the composition further comprises water and a polyol.

In some embodiments of the present invention, the composition for hair care comprises the following components: cationic polyaspartic acid, polyol and water.

According to the present invention, the composition for hair care has a distribution ratio of: cationic biopolymer 10-25wt%, preferably 15-20wt%, polyol content ≤50wt%, preferably 0-50wt%, more preferably 35-40wt%, and the rest is water.

Preferably, the polyol includes one or more of ethylene glycol, propylene glycol, butylene glycol, hexylene glycol and glycerol.

Those skilled in the art should understand that the so-called "the polyol includes one or more of ethylene glycol, propylene glycol, butylene glycol, hexylene glycol and glycerol" refers to one of the listed polyols, or a mixture of two or more of the listed polyols in any proportion.

According to the present invention, the composition further comprises cosmetically acceptable solvents, surfactants, foaming agents and other adjuvants.

Among them, the acceptable solvents, surfactants, foaming agents and other auxiliary agents in the cosmetics of the present invention include but are not limited to ingredients that can affect the sensory properties, skin permeability and bioavailability of the cosmetic active agent of the present invention. More specifically, they include: solvents, such as water or oil, wherein the oil includes petroleum, animal oil, vegetable oil or synthetic oil, such as but not limited to peanut oil, soybean oil, mineral oil, sesame oil, castor oil; surfactants, such as but not limited to polysorbate, sorbitan ester; biologically active ingredients, such as but not limited to betaine, glycoside, maltoside; thickeners, such as but not limited to fatty alcohol, nonoxynol ether, polyoxyethylene, polyethylene glycol, etc.

The research results show that the composition for hair care prepared with the cationic biopolymer as described in the first aspect of the present invention or the cationic biopolymer prepared by the preparation method as described in the second aspect of the present invention has the following advantages:

(1) Compared with anionic polymers represented by polyacidic amino acids, cationic biopolymers, which are the main active ingredients contained in the composition for hair care of the present invention, have better hair conditioning and repairing effects;

(2) The cationic biopolymer, the main active ingredient contained in the hair care composition of the present invention, has a quaternary ammonium salt derivative that is stably bonded to the side chain carboxyl group of the polyacidic amino acid through a covalent bond, and the degree of substitution is controllable.

(3) The cationic biopolymer, the main active ingredient contained in the hair care composition of the present invention, is grafted on a polypeptide chain obtained by polymerization of aspartic acid and has good bioaffinity compared to other types of cationic polymers.

The fourth aspect of the present invention provides use of the composition according to the third aspect of the present invention in preparing hair care products.

The fifth aspect of the present invention provides a hair care product comprising the composition according to the third aspect of the present invention.

It is easy to understand that the contents of the third to fifth aspects above relate to the use of the cationic biopolymer described in the first aspect above or the cationic biopolymer prepared by the preparation method described in the second aspect above in hair care products.

III. Testing instruments and methods

In the present invention, liquid chromatography is used to detect the molecular weight of the polyacidic amino acid by using a liquid chromatograph (Shimadzu LC-20A).

The present invention adopts an in vitro experimental method to verify the efficacy of the composition for use in cleaning products.

Example

In order to make the present invention easier to understand, the present invention will be further described in detail below in conjunction with examples, which are merely illustrative and are not intended to limit the scope of application of the present invention. The raw materials or components used in the present invention can be obtained by commercial routes or conventional methods unless otherwise specified.

Example 1: Preparation of cationic biopolymers by substitution with glycidyltrimethylammonium chloride

Accurately weigh 272.0g of NaOH, place it in 1800mL of deionized water and completely dissolve it to obtain a NaOH aqueous solution. Accurately weigh 600.0g of polysuccinimide (degree of polymerization is 310), place it in the above-mentioned NaOH aqueous solution, and completely dissolve it under stirring to obtain a sodium polyaspartate aqueous solution. The pH of the above solution is adjusted to 4.50 with a 1mol/L phosphoric acid aqueous solution. Add 1034.0g of glycidyl trimethylammonium chloride, react for 5h at a water bath temperature of 50°C to obtain a polyaspartic acid/glycidyl trimethylammonium chloride aqueous solution. After the above-mentioned aqueous solution is ultrafiltered to remove small molecules with a molecular weight of less than 3kDa, 959.6g of light yellow powder, i.e., a cationic biopolymer (cationized polyacidic amino acid), is obtained by freeze-drying.

It can be confirmed by GPC that low molecular weight compounds (free salts, unreacted reagents, etc.) in the obtained powder have been removed.

The structure was confirmed by IR (Fourier transform infrared analyzer, Varian 3100, Varian, USA) (see Figure 2). Compared with polyaspartic acid, the sample can detect a characteristic peak of an ester bond carbonyl group added near 1710, confirming that the side chain carboxyl group of polyaspartic acid is grafted with a propyl-trimethylammonium group by an ester bond. When the structure was confirmed by ¹ H-NMR (nuclear magnetic resonance spectrometer, AV600, Bruker, USA) (see Figure 3), the signal from the methyl hydrogen atom of trimethylammonium was detected, confirming that the side chain carboxyl group of polyaspartic acid is grafted with a propyl-trimethylammonium group by an ester bond. The structure was confirmed by ¹³ C-NMR (nuclear magnetic resonance spectrometer, AV600, Bruker, USA) (see Figure 4). In addition, the average degree of substitution can be calculated from the integral value of the methyl carbon atom peak and the amide bond carbon atom peak of ¹³ C-NMR, and the substitution degree of the cationic biopolymer is 54%.

Example 2: Preparation of cationic biopolymers by substitution with glycidyltrimethylammonium chloride

Polysuccinimide with a polymerization degree of 103 was used as the raw material, and the other process conditions were the same as those in Example 1. The degree of substitution of the product was calculated as 61% by the integral value of the methyl carbon atom peak and the amide bond carbon atom peak of ¹³ C-NMR.

Example 3: Preparation of cationic biopolymers by substitution with glycidyl trimethylammonium chloride

Polysuccinimide with a polymerization degree of 488 was used as the raw material, and the other process conditions were the same as those in Example 1. The degree of substitution of the product was calculated as 49% by the integration value of the methyl carbon atom peak and the amide bond carbon atom peak of ¹³ C-NMR.

Example 4: Preparation of cationic biopolymers by substitution with glycidyltrimethylammonium chloride

The amount of NaOH added was 158.9 g, the amount of polysuccinimide added was 350.0 g, and the other process conditions were the same as those in Example 1. The degree of substitution of the product was calculated to be 55% by the integral value of the methyl carbon atom peak and the amide bond carbon atom peak of ¹³ C-NMR.

Example 5: Preparation of cationic biopolymers by substitution with glycidyltrimethylammonium chloride

The pH of the reaction system was adjusted to 4.85, and the other process conditions were the same as those in Example 1. The degree of substitution of the product was calculated to be 39% by the integration value of the methyl carbon atom peak and the amide bond carbon atom peak of ¹³ C-NMR.

Example 6: Preparation of cationic biopolymers by substitution with glycidyltrimethylammonium chloride

The temperature of the reaction system was adjusted to 40° C., and the other process conditions were the same as those in Example 1. The degree of substitution of the product was calculated to be 44% by the integration value of the methyl carbon atom peak and the amide bond carbon atom peak of ¹³ C-NMR.

Example 7: Preparation of cationic biopolymers by substitution with glycidyltrimethylammonium chloride

The reaction time was 24 h, and the other process conditions were the same as those in Example 1. The degree of substitution of the product was calculated to be 57% by the integration value of the methyl carbon atom peak and the amide bond carbon atom peak of ¹³ C-NMR.

Example 8: Preparation of cationic biopolymers by substitution with glycidyltrimethylammonium chloride

Except that the pH value of the reaction system was adjusted to 4.61, the rest of the process was the same as in Example 1. The reaction yielded 889.4 g of light yellow powder with a degree of substitution of 43%.

Example 9: Preparation of cationic biopolymers by substitution with glycidyltrimethylammonium chloride

Except that the reaction temperature was 60° C., the rest of the process was the same as in Example 1. The reaction yielded 939.9 g of light yellow powder with a substitution degree of 54%.

Example 10: Preparation of cationic biopolymers by substitution with glycidyltrimethylammonium chloride

Except for the reaction time of 8 hours, the rest of the process is the same as that of Example 1. The reaction yields 921.8 g of light yellow powder with a substitution degree of 54%.

Example 11: Preparation of cationic biopolymers by substitution with glycidyl triethylammonium chloride

Accurately weigh 272.0g of NaOH, place it in 1800mL of deionized water and completely dissolve it to obtain a NaOH aqueous solution. Accurately weigh 600.0g of polysuccinimide (degree of polymerization is 310), place it in the above NaOH aqueous solution, and completely dissolve it under stirring to obtain a sodium polyaspartate aqueous solution. The pH of the above solution is adjusted to 4.50 with a 1mol/L phosphoric acid aqueous solution. Add 1320.0g of glycidyl triethylammonium chloride, react at a water bath temperature of 50°C for 5h, and obtain a polyaspartic acid/glycidyl triethylammonium chloride aqueous solution. After the above aqueous solution is ultrafiltered to remove small molecules with a molecular weight of less than 3kDa, 1049.8g of light yellow powder, i.e., a cationic biopolymer, is obtained by freeze-drying.

A sample was taken for ¹³ C-NMR analysis and the substitution degree of the cationic biopolymer was calculated to be 51% using the integrated value of the methyl carbon atom peak and the amide bond carbon atom peak.

Example 12: Pilot scale-up of the cationic biopolymer preparation process

90L of deionized water was added to a 250L reaction tank, and 13.6kg of NaOH was slowly added under stirring and cooling water conditions. After NaOH was completely dissolved and the solution temperature was about to reach room temperature, 30.0kg of polysuccinimide (degree of polymerization was 310) was slowly added to the reaction tank under stirring and cooling water conditions to completely dissolve it to obtain a sodium polyaspartate aqueous solution, and the pH of the above solution was adjusted to 4.50 with a 1mol/L phosphoric acid aqueous solution. After that, the temperature of the reaction system in the reaction tank was stabilized to 50°C by circulating hot water, and 51.7kg of glycidyl trimethyl ammonium chloride was added to the reaction tank. After stirring and reacting for 6h, a polyaspartic acid/glycidyl trimethyl ammonium chloride aqueous solution was obtained. After the above aqueous solution was ultrafiltered to remove small molecules with a molecular weight of less than 3kDa, 47.22kg of light yellow powder, i.e., a cationic biopolymer, was obtained by spray drying. The sample was subjected to ¹³ C-NMR analysis, and the substitution degree of the cationic biopolymer was calculated to be 53% using the integral value of the methyl carbon atom peak and the amide bond carbon atom peak.

Example 13: Preparation of cationic biopolymers according to the method of Example 1

Accurately weigh 272.0g of NaOH, place it in 1800mL of deionized water and completely dissolve it to obtain a NaOH aqueous solution. Accurately weigh 600.0g of polysuccinimide (degree of polymerization is 310), place it in the above-mentioned NaOH aqueous solution, and completely dissolve it under stirring to obtain a polyacidic amino acid sodium aqueous solution. Adjust the pH of the above solution to 4.50 with a 1mol/L phosphoric acid aqueous solution. Add 1034.0g of glycidyl trimethylammonium chloride, react for 5h at a water bath temperature of 50°C, and obtain a polyacidic amino acid/glycidyl trimethylammonium chloride aqueous solution. After removing small molecules with a molecular weight of less than 3kDa from the above aqueous solution by ultrafiltration, store it at low temperature for later use.

The concentration of the cationic biopolymer was determined to be 31.1 wt % by drying method. Low molecular weight compounds (free salts, unreacted reagents, etc.) in the obtained powder were confirmed to have been removed by GPC. IR, 1H-NMR and 13C-NMR were used to confirm that the side chain carboxyl groups of the polyacidic amino acid were grafted with propyl-trimethylammonium groups by ester bonds, and the average substitution degree was calculated by the integral value of the methyl carbon atom peak and the amide bond carbon atom peak of 13C-NMR, and the substitution degree of the cationic biopolymer was 54%.

Example 14: Preparation of shampoo and hair care product composition

The cationic biopolymer powder obtained by the method of Example 1 was mixed with deionized water to obtain a solution with a concentration of 20 wt%, and then sterilized at 90° C. for 30 min. Hexylene glycol was added to the obtained sterilized solution at a mass ratio of 30:1 as an antibacterial component to obtain a shampoo and hair care composition, which was stored at low temperature and away from light.

Example 15: In vitro efficacy evaluation

(1) Hair combing performance test

The cationic biopolymer composition obtained in Example 14 was tested for hair combing performance. The materials and equipment required for the test include: undamaged human hair bundles, INSTRON 5942 tensile testing machine, and clamps. The test samples were diluted with pure water to obtain test samples with concentrations of 0.40, 1.00, and 3.00 (%, W/V), respectively, and pure water was used as a blank control, and a 20 wt% sodium polyaspartate aqueous solution with a concentration of 1.00 (%, W/V) was used as a negative control.

The test methods include:

(a) The experimental hair bundles were washed with deionized water and neutral shampoo before use, and then dried overnight at room temperature. The ends and roots of the hair were cut off. After that, different hair bundles were sprayed with pure water and the sample solution with different concentration gradients, and then dried at room temperature at 40% humidity for use.

(b) Hair bundle combing test: debug the tensile testing machine, connect the host computer, open the test software, preheat for half an hour, and set the relevant parameters (hair thickness 0.4cm, hair width 3cm, speed 300mm/min). Take the treated hair bundles, comb them with a comb, and then fix one end of the hair bundle to be tested with a suitable clamp, and place it naturally in the middle of the comb. Select the tensile value between 20 and 90mm for the tensile test. Repeat the test on the same hair bundle 3 times and take the average value to reduce the measurement error caused by different hair bundles.

The test results are shown in Figure 5. It can be seen that the cationic biopolymer composition has a significant improvement effect on hair combing performance within a suitable concentration range.

(2) Hair damage repair test

The cationic biopolymer composition obtained in Example 14 was subjected to a hair damage repair test. The materials and equipment required for the test include: heat-damaged human hair bundles, SU1510 electron scanning electron microscope, and SDC-500 contact angle tester. The test sample was diluted with pure water to obtain a test sample with a concentration of 0.35 (%, W/V), and pure water was used as a blank control, and a 20 wt% sodium polyaspartate aqueous solution with a concentration of 0.35 (%, W/V) was used as a negative control.

The test methods include:

(a) Hair bundle pretreatment: The experimental hair bundles were washed with deionized water and neutral shampoo before use, and after drying at room temperature overnight, the hair ends and roots were cut off. Then, different hair bundles were immersed in pure water and sample solutions respectively, taken out after 30 minutes, and dried at room temperature overnight at 40% humidity for use.

(b) Observation of hair damage repair performance by electron microscopy: A hair was randomly selected from the heat-damaged hair bundle treated with pure water and the sample solution, and the middle intact part of about 1 cm was cut off to make an electron microscopy sample. The hair surface layer and its scale morphology and distribution were observed under a scanning electron microscope.

(c) Observation of hair damage repair performance by hanging drop method: Heat-damaged hair strands treated with pure water and sample solution were fixed on the fixture of a contact angle tester. Ultrapure water was used as the medium and the contact angle of ultrapure water on the hair surface was observed and recorded.

The test results are shown in Figure 6 (a is the blank control, b is the negative control, and c is the sample solution) and Table 1. It can be seen that the cationic biopolymer can almost completely fill the peeling and damaged parts of the hair scales, and the surface scales are arranged in a tile-like overlapping manner, making the hair flat and smooth; and the contact angle between the hair bundle and ultrapure water is greater than 90°, showing hydrophobicity, and has obvious performance in repairing hair damage.

Table 1 Contact angles of ultrapure water and hair samples

(3) Hair adsorption performance test

The cationic biopolymer composition obtained in Example 14 was tested for hair adsorption performance. The materials and equipment required for the test include: undamaged human hair bundles, electronic balance. The test samples were diluted with pure water to obtain test samples with concentrations of 0.20 and 0.65 (%, W/V), respectively, and pure water was used as a blank control, and a 20 wt% sodium polyaspartate solution with a concentration of 0.65 (%, W/V) was used as a negative control.

The test methods include:

(a) Hair bundle pretreatment: The experimental hair bundles were washed with deionized water and neutral shampoo before use, and then dried overnight at room temperature. The ends and roots of the hair were cut off for later use.

(b) Adsorption performance test

The hair bundles were immersed in pure water, control solution and sample solutions with different concentration gradients, taken out after 10 minutes and rubbed with distilled water for 3 times, and dried at room temperature for 8 hours at 40% humidity. Three groups were tested in parallel for each experiment and the average value was taken to reduce the measurement error caused by different hair bundles. The adsorption rate of the hair bundle on the sample was calculated by the following formula.

Adsorption rate (%) = hair weight increase/initial hair weight × 100%

The test results are shown in Table 2. It can be seen that the hair bundles treated with the sample solution increased significantly in weight, indicating that the cationic biopolymer has good affinity for hair.

Table 2 Hair bundle adsorption performance test results

It should be noted that the embodiments described above are only preferred embodiments of the present invention, which are used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims (10)

1. A cationic biopolymer which is a cationized polyacid type amino acid formed by substituting at least a part of hydrogen atoms of carboxyl groups in the side chain of polyacid type amino acid by a group with a quaternary ammonium cation group, and the molecular structure of the cationized polyacid type amino acid is shown as the formula (I):

in the formula (I), A is a hydrogen atom or a substituent shown in the following formula (II) or formula (III); the average degree of substitution of the above-mentioned substituents is 30 to 80%, m and n are positive integers representing the degree of polymerization and represent the number of the polymerized monomer residues of only two configurations, respectively, the sum of m and n is 10 to 2500,

in the formula (II) or (III), R1 represents an alkylene group having 1 to 2 carbon atoms, and R2, R3 and R4 each represent an alkyl group having 1 to 3 carbon atoms.

2. The cationized biopolymer according to claim 1, wherein the cationized biopolymer is obtained by reacting a polyacid-type amino acid with a cationizing agent, wherein the cationizing agent comprises one or more compounds having a molecular structure represented by formula (IV):

in the formula (IV), R ₅ Represents an alkylene group having 1 to 3 carbon atoms, R ₂ 、R ₃ And R ₄ Each represents an alkyl group having 1 to 3 carbon atoms, and X represents a halogen atom.

3. A method of preparing the cationic biopolymer of claim 1 or 2, comprising the steps of:

s1, placing the polysuccinimide in an alkaline aqueous solution, and stirring at room temperature to obtain a polyacid amino acid salt aqueous solution through a ring-opening hydrolysis reaction;

s2, adjusting the pH value of the polyacid amino acid salt aqueous solution to acidity by using a water-soluble acid aqueous solution, then adding a cationizing agent, and carrying out ring-opening esterification reaction to obtain a cationic biopolymer aqueous solution;

and S3, removing small molecular substances from the cationic biopolymer aqueous solution, and drying to obtain a white or light yellow or brown yellow powdery cationic biopolymer.

4. The production method according to claim 3,

in step S1, the molecular weight of the poly-acidic amino acid salt is 1-250 kDa; preferably, the concentration of the aqueous solution of the poly acidic amino acid salt is 8 to 55wt%;

and/or the alkaline aqueous solution is NaOH or KOH aqueous solution; preferably, the concentration of the alkaline aqueous solution is 1 to 10mol/L;

and/or the water-soluble acid comprises one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and citric acid; preferably, the concentration of the water-soluble acid in the water solution is 1 to 3mol/L.

5. The production method according to claim 3 or 4, wherein in step S2, the reaction conditions of the ring-opening esterification reaction include: the pH value is 4.20-4.90, the reaction temperature is 40-70 ℃, and the reaction time is 1-8 h; and/or in step S3, the method for removing the small molecular substances by the cationic biopolymer aqueous solution is membrane filtration, and the drying method comprises freeze drying and spray drying.

6. A composition for hair rinse comprising the cationic biopolymer according to claim 1 or 2 or the cationic biopolymer produced by the manufacturing process according to any one of claims 3-5, said composition being capable of repairing and/or conditioning damaged hair; preferably, the cationic biopolymer is present in the composition in an amount of 20wt% to 50wt%.

7. The composition of claim 6, further comprising water and a polyol; preferably, the composition comprises 10-25 wt% of cationic biopolymer, 100wt% of water Qsp and less than or equal to 50wt% of polyol; further preferably, the polyhydric alcohol comprises one or more of ethylene glycol, propylene glycol, butylene glycol, hexylene glycol and glycerol.

8. Composition according to claim 6 or 7, characterized in that it further comprises cosmetically acceptable solvents, surfactants, foaming agents and other adjuvants.

9. Use of a composition according to any one of claims 6 to 8 for the preparation of a hair care product.

10. A hair wash comprising a composition according to any one of claims 6 to 8.

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