Heterocyclic polyhydric alcohol acid compound as well as preparation method and application thereof

Abstract

The invention discloses a heterocyclic polyhydric alcohol acid compound as well as a preparation method and application thereof. The heterocyclic polyhydric alcohol acid compound has a structure as shown in a formula I, # imgabs0 #, Y comprises a substituted or unsubstituted heterocyclic group, R1 and R2 are independently selected from substituted or unsubstituted alkyl or substituted or unsubstituted aryl, and X comprises oxygen or sulfur. Hydroxyl / sulfydryl contained in the heterocyclic polyhydric alcohol acid compound enables the compound to be used as a polyurethane chain extender, carboxylic acid groups contained in the heterocyclic polyhydric alcohol acid compound enable the compound to be salified to prepare waterborne polyurethane, and amido bonds contained in the heterocyclic polyhydric alcohol acid compound enable synthesized polyurethane to have intermolecular hydrogen bonds, so that the mechanical property of the polyurethane is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of organic chemistry, and specifically relates to a heterocyclic polyol acid compound and a preparation method and application thereof. Background Art

[0002] Polyurethane is one of the most widely used polymer materials. Due to its high wear resistance, high flexibility, strong bonding strength and excellent chemical resistance, it can meet the needs of various applications and has been widely used in coatings, home appliances, automobiles, construction and other fields. However, traditional polyurethane uses a large amount of organic solvents in the preparation process, resulting in high toxicity and strong pollution of the final product. With the strengthening of human environmental awareness, the development of safe, non-toxic, solvent-free, green and environmentally friendly polyurethane has become a development trend.

[0003] Waterborne polyurethane has received more and more attention due to its green and environmentally friendly performance and has broad application prospects. Isocyanates, polyols, chain extenders, salt formers and other additives are used in the preparation process of waterborne polyurethane. Chain extenders play an important role in the synthesis of polyurethane. Chain extenders with different functional group structures will lead to innovations in polyurethane materials. Therefore, in-depth research on chain extenders has become one of the hot topics of polyurethane materials. Summary of the invention

[0004] In order to solve all or part of the above technical problems, this application provides the following technical solutions:

[0005] The main purpose of the present application is to provide a heterocyclic polyol acid compound having a structure shown in formula I

[0006]

[0007] Wherein, Y includes a substituted or unsubstituted heterocyclic group, R1 and R2 are independently selected from a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and X includes oxygen or sulfur. The substituted or unsubstituted alkyl group may be a straight chain alkyl group or a branched chain alkyl group.

[0008] The beneficial effect of the above technical solution is that due to the presence of atoms such as oxygen, sulfur, and nitrogen in the heterocyclic group, intermolecular hydrogen bonds will be formed, and using them in the synthesis of polyurethane is beneficial to improving the mechanical properties of polyurethane; at the same time, due to the rigid structure of the heterocyclic group, the mechanical properties of polyurethane can be further improved.

[0009] In some embodiments, in the heterocyclic polyol acid compound, Y includes a nitrogen heterocycle, an oxygen heterocycle or a sulfur heterocycle. Preferably, Y includes a furan group, a tetrahydrofuran group, a pyrrole group, a pyridine group, a piperidine group, a thiophene group, an imidazole group or a pyrazine group. More preferably, Y includes a 2,5-furan group, a 2,5-tetrahydrofuran group, a 2,5-pyrrole group or a 2,5-thiophene group.

[0010] In some embodiments, in the heterocyclic polyol acid compound, R1 and R2 are independently selected from substituted or unsubstituted C1-C6 straight chain or branched alkyl or substituted or unsubstituted aromatic ring. Further, R1 and R2 are independently selected from C1-C6 straight chain or branched or substituted or unsubstituted phenyl.

[0011] Preferably, R1 and R2 are independently selected from methyl, ethyl, propyl, isopropyl, butyl, benzene ring or phenethyl.

[0012] The second object of the present application is to provide a method for preparing a heterocyclic polyol acid compound, the preparation method comprising: subjecting a heterocyclic compound and a compound M to an amidation reaction, wherein the heterocyclic group of the heterocyclic compound has at least two substitution chains, and each of the substitution chains has at least one active group, the compound M contains an amino group and a carboxyl group, and also contains a hydroxyl group and / or a thiol group, and at least one amino group on the compound M undergoes the amidation reaction with the active group.

[0013] In some embodiments, the compound M has a structure shown in Formula II:

[0014]

[0015] Wherein, R includes a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and X includes oxygen or sulfur.

[0016] In some preferred embodiments, the compound M includes at least one of 2-amino-4-hydroxybenzoic acid, 4-amino-3-hydroxybenzoic acid, 2-amino-3-p-hydroxyphenylpropionic acid, 2-amino-3-hydroxypropionic acid, 2-amino-3-mercaptopropionic acid and 2-amino-3-hydroxybutyric acid. Compound M can be derived from bio-based materials and has the characteristics of being non-toxic, biocompatible and degradable.

[0017] In some embodiments, the heterocyclic compound has a structure shown in Formula III,

[0018] R4-Y-R3

[0019] III

[0020] Wherein, Y includes a substituted or unsubstituted heterocyclic group, and R3 and R4 are independently selected from an ester group or an acyl chloride group.

[0021] In some preferred embodiments, Y includes a furan group, a tetrahydrofuran group, a pyrrole group, a pyridine group, a piperidine group, a thiophene group, an imidazole group or a pyrazine group. More preferably, the heterocyclic compound includes at least one of 2,5-pyrrole dicarbonyl chloride, 2,5-tetrahydrofuran dimethyl ester, 2,5-furan dicarbonyl chloride, 2,5-thiophene dicarbonyl chloride, 4,6-pyrimidine dicarbonyl chloride and 2,6-pyridine dicarbonyl chloride.

[0022] Furthermore, the preparation method comprises: uniformly dispersing the compound M represented by formula II and the heterocyclic compound represented by formula II in a solution to form a mixed reaction solution, so as to carry out the amidation reaction.

[0023] Furthermore, the preparation method specifically comprises: uniformly dispersing the heterocyclic compound and compound M in a solvent to form a mixed reaction liquid, adjusting the pH of the mixed reaction liquid to 7 to 8.5, and performing the amidation reaction at a temperature of 0 to 50° C. to obtain the heterocyclic polyol acid compound. The solvent includes, but is not limited to, a combination of one or more non-aqueous solvents such as water or an organic solvent, an ionic liquid, etc. Exemplarily, the organic solvent can be selected from at least one of monoalcohols, ethers, ketones, halogenated hydrocarbons, nitrogen compounds, and sulfur compounds.

[0024] In some preferred embodiments, the heterocyclic compound is uniformly dispersed in a first solvent to form a solution A, the compound M is uniformly dispersed in a second solvent to form a solution B, and the solution A and the solution B are uniformly mixed to obtain the mixed reaction liquid; the first solvent and the second solvent are independently selected from at least one of water, chloroform, dichloroethane, carbon tetrachloride, ethanol, THF (tetrahydrofuran), acetone, dichloromethane, DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide).

[0025] In some embodiments, in the mixed reaction solution, the molar ratio of the heterocyclic compound to the compound M is 1:2 to 1:10. Preferably, the molar ratio of the heterocyclic compound to the compound M is 1:2 to 1:4.

[0026] In some embodiments, the reaction time of the amidation reaction is 1 to 10 hours.

[0027] In some embodiments, after the amidation reaction is completed, the reaction product is post-treated, and the post-treatment includes: first adjusting the pH of the reaction product to 4-5 with an acid, and then purifying it.

[0028] In some embodiments, the amidation reaction can be carried out in the presence of an auxiliary agent, etc. Exemplarily, the auxiliary agent can include a catalyst, etc. The catalyst includes but is not limited to one or more of triethylamine, pyridine, sodium ethoxide and sodium carbonate.

[0029] In some embodiments, the entire synthesis reaction of the heterocyclic polyol acid compound can be carried out in one reaction container, that is, synthesized by a one-pot reaction.

[0030] The third object of the present application is to provide a heterocyclic polyol acid compound prepared by the preparation method described in the above technical scheme.

[0031] A fourth object of the present application is to provide a derivative of any of the heterocyclic polyol acid compounds described above, wherein the derivative includes at least one of a salt, an ester, and an amide.

[0032] The fifth object of the present application is to provide the use of the heterocyclic polyol acid compound in the above technical scheme in the preparation of a polyurethane chain extender or as a polyurethane chain extender.

[0033] The sixth object of the present application is to provide a method for synthesizing waterborne polyurethane, comprising: reacting a mixed reaction system comprising isocyanate, polyol, solvent and chain extender to obtain waterborne polyurethane; wherein the chain extender comprises the heterocyclic polyol acid compound described in any one of the above technical schemes.

[0034] Compared with the prior art, this application has at least the following technical effects:

[0035] (1) The present application provides a heterocyclic polyol acid compound, which contains a hydroxyl / thiol group, a carboxylic acid group and a heterocyclic group. The hydroxyl / thiol group enables the compound to be used as a polyurethane chain extender, and the carboxylic acid group can form a salt to increase the solubility of the polyurethane in water to prepare a water-soluble polyurethane. When the heterocyclic polyol acid compound is used to synthesize polyurethane, the rigid structure of the heterocyclic group in its structure and the intermolecular hydrogen bonds formed by the amide bonds can improve the mechanical properties of the polyurethane.

[0036] (2) The novel heterocyclic polyol acid compound is semi- / entirely bio-based and has the advantages of being non-toxic, biocompatible, and biodegradable. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 This is the NMR characterization image of the heterocyclic polyol acid compound prepared in Example 2 of the present application. DETAILED DESCRIPTION

[0039] The technical solution of the present application is described in detail below in conjunction with specific embodiments so that those skilled in the art can better understand and implement the technical solution of the present application. The specific functional details disclosed herein should not be interpreted as being restrictive, but only as the basis for the claims and as a representative basis for teaching those skilled in the art to adopt the present application in different ways in any appropriate detailed embodiment.

[0040] Embodiment 1:

[0041] Weigh 15 g of 2-amino-3-p-hydroxyphenylpropionic acid and dissolve it in water, and adjust the pH to 8.0-8.5; dissolve 4.0 g of 2,5-pyrrole dicarbonyl chloride in chloroform;

[0042] At 10-15°C, add 2,5-pyrrole dicarboxylic acid chloride solution to 2-amino-3-p-hydroxyphenylpropionic acid solution and maintain the pH between 8.0 and 8.5. After the addition is completed, continue the reaction for 2 hours. After the reaction is completed, use acid to neutralize the reaction product to a pH of about 5, and then use a silica gel column to purify the product with a yield of 68%.

[0043] 1 H NMR data: δ 12.86 (s, 2H), 12.38 (s, 1H), 9.36 (s, 2H), 9.06 (s, 2H), 7.71 (s, 2H), 9.96 (d, 2H), 6.68 (d, 2H), 4.72 (t, 2H), 3.12 (m, 4H).

[0044] The product structure is as follows:

[0045]

[0046] Embodiment 2:

[0047] Dissolve 10 g of 2-amino-5-hydroxybenzoic acid in an alkaline aqueous solution, and control the pH at 7.5±0.5; weigh 4.2 g of 2,5-furandicarboxylic acid chloride and dissolve it in dichloroethane;

[0048] At 15±5°C, the acyl chloride solution was slowly added dropwise to the 2-amino-5-hydroxybenzoic acid solution, and the pH was maintained between 7.5 and 8.0 using pyridine. After the addition was completed, stirring was continued for 2 hours. After the reaction was completed, the upper aqueous solution was taken, neutralized with hydrochloric acid to a pH of 4 to 5, and then purified using a silica gel column to obtain the product with a yield of 69%.

[0049] The NMR spectrum of the product is Figure 1 As shown, 1 H NMR data: δ 13.08 (s, 2H), 12.05 (s, 2H), 9.43 (s, 2H), 8.48 (d, 2H), 7.66 (d, 4H), 7.23 (dd, 2H).

[0050] The product structure is as follows:

[0051]

[0052] Embodiment 3:

[0053] Weigh 20g of 2-amino-3-mercaptopropionic acid and dissolve it in water, and adjust the pH to between 8.0 and 8.5; weigh 10.5g of 2,5-thiophene dicarbonyl chloride and dissolve it in dichloroethane;

[0054] At 10±5°C, the 2,5-thiophenedicarboxylic acid chloride solution was added dropwise to the 2-amino-3-mercaptopropionic acid solution, and the pH was maintained between 8.0 and 8.5 using sodium carbonate. After the addition was completed, the reaction was continued for 3 hours. After the reaction was completed, the pH of the reaction product was adjusted to between 4 and 4.5 using an acid, and then the product was purified using a silica gel column with a yield of 43%.

[0055] 1 H NMR data: δ 12.45 (s, 2H), 8.78 (s, 2H), 8.45 (s, 2H), 4.78 (t, 2H), 3.15 (m, 4H), 1.43 (s, 2H).

[0056] The product structure is:

[0057]

[0058] Embodiment 4:

[0059] Weigh 15g of 2-amino-3-hydroxypropionic acid and dissolve it in water, and adjust the pH to between 7.5 and 8.0; weigh 7.8g of 2,5-tetrahydrofuran dimethyl ester and dissolve it in carbon tetrachloride;

[0060] At room temperature, the 2,5-tetrahydrofuran dimethyl ester solution was added dropwise to the 2-amino-3-hydroxypropionic acid solution, and the pH was maintained between 7.0 and 8.0 using triethylamine. After the addition was completed, the reaction was continued for 3 hours. After the reaction was completed, the pH of the reaction product was adjusted to between 4.5 and 5.0 using an acid, and then the product was purified using a silica gel column with a yield of 57%.

[0061] 1H NMR data: δ 12.39 (s, 2H), 8.36 (s, 2H), 4.94 (s, 2H), 4.69 (m, 2H), 4.16 (m, 4H), 4.06 (m, 2H), 2.21 (m, 4H).

[0062] The product structure is:

[0063]

[0064] Embodiment 5:

[0065] Weigh 20g of 2-amino-3-hydroxybutyric acid and dissolve it in water, and adjust the pH to between 7.5 and 8.0; weigh 12g of 4,6-pyrimidinedicarbonyl chloride and dissolve it in carbon tetrachloride;

[0066] Under ice bath conditions, the 4,6-pyrimidinedicarboxylic acid chloride solution was added dropwise to the 2-amino-3-hydroxybutyric acid solution, and the pH was maintained between 7.5 and 8.0. After the addition was completed, the reaction was continued for 2 hours. After the reaction was completed, the pH of the reaction product was adjusted to between 4.0 and 4.5 with an acid, and then the product was purified using a silica gel column with a yield of 68%.

[0067] 1 H NMR data: δ 12.39 (s, 2H), 9.89 (s, 1H), 9.46 (s, 1H), 9.38 (s, 2H), 5.37 (s, 2H), 4.64 (m, 2H), 4.37 (d, 2H), 1.16 (d, 6H).

[0068] The product structure is:

[0069]

[0070] Embodiment 6:

[0071] Weigh 20g of 2-amino-2-hydroxyacetic acid and dissolve it in water, and adjust the pH to between 8.0 and 8.5; weigh 9.6g of 2,6-pyridinedicarbonyl chloride and dissolve it in carbon tetrachloride;

[0072] Under ice bath conditions, 2,6-pyridinedicarbonyl chloride solution was added dropwise to 2-amino-2-hydroxyacetic acid solution, and the pH was maintained between 7.5 and 8.0. After the addition was completed, the reaction was continued for 2 hours. After the reaction was completed, the pH of the reaction product was adjusted to between 4.0 and 4.5 with an acid, and then the product was purified using a silica gel column with a yield of 56%.

[0073] 1H NMR data: δ 12.23 (s, 2H), 10.38 (s, 2H), 8.80 (d, 2H), 8.56 (t, 1H), 6.57 (s, 2H), 4.12 (s, 2H).

[0074]

[0075] Embodiment 7:

[0076] The heterocyclic polyol acid compound obtained in Example 2 is used as a chain extender in the synthesis of polyurethane:

[0077] Weigh 50 g of polytetrahydrofuran (number average molecular weight of 1000), 20.8 g of isophorone diisocyanate, and 80 ml of acetone, heat to 70 ° C for reaction for 3 h, then add 6.53 g of the chain extender in Example 2, heat to 100 ° C for reaction for 5 h, cool to 50 ° C, add 3.5 g of triethylamine for neutralization, add 200 g of water and stir for 30 min, then remove acetone by reduced pressure distillation to obtain waterborne polyurethane.

[0078] The prepared specimens were dried and the tensile strength was tested by a universal testing machine to be 29.3 MPa. The waterborne polyurethane was successfully prepared, indicating that the product in Example 2 can be used as a polyurethane chain extender.

[0079] Comparative Example 1:

[0080] The difference between Comparative Example 1 and Example 1 is that the chain extender used in Example 7 is replaced by dimethylol propionic acid, and the other operation steps are consistent with Example 7. The comparative specimen is prepared by the same steps as Example 7, and the tensile strength thereof is 21.6 MPa.

[0081] It can be seen that the chain extender prepared by the present invention provides more intermolecular hydrogen bonds due to the presence of amide bonds, and based on the rigid structure of the heterocyclic group, it can improve the mechanical properties of the synthesized polyurethane.

[0082] The various aspects, embodiments, features and examples of the present application should be considered as illustrative in all aspects and are not intended to limit the present application, the scope of which is defined solely by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the present application as claimed.

[0083] In addition, the applicant 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.

[0084] Although the present application has been described with reference to illustrative embodiments, it will be understood by those skilled in the art that various other changes, omissions and / or additions may be made without departing from the spirit and scope of the present application and that the elements of the embodiments may be replaced by substantial equivalents. In addition, many modifications may be made without departing from the scope of the present application to adapt specific circumstances or materials to the teachings of the present application. Therefore, it is not intended herein to limit the present application to the disclosed specific embodiments for performing the present application, but it is intended that the present application will include all embodiments within the scope of the appended claims. In addition, unless specifically stated, any use of the terms first, second, etc. does not indicate any order or importance, but rather uses the terms first, second, etc. to distinguish one element from another element.

Claims

1. A heterocyclic polyol acid compound, characterized in that: The heterocyclic polyol acid compound has a structure shown in Formula I, Wherein, Y includes a substituted or unsubstituted heterocyclic group, R1 and R2 are independently selected from substituted or unsubstituted alkyl or substituted or unsubstituted aryl, and X includes oxygen or sulfur.

2. The heterocyclic polyol acid compound according to claim 1, characterized in that: In the heterocyclic polyol acid compound, Y includes a nitrogen heterocycle, an oxygen heterocycle or a sulfur heterocycle; Preferably, Y comprises a furan group, a tetrahydrofuran group, a pyrrole group, a pyridine group, a piperidine group, a thiophene group, an imidazole group or a pyrazine group; More preferably, Y includes 2,5-furanyl, 2,5-tetrahydrofuranyl, 2,5-pyrrolyl or 2,5-thienyl.

3. The heterocyclic polyol acid compound according to claim 1, characterized in that: R1 and R2 are independently selected from substituted or unsubstituted C1-C6 straight chain or branched alkyl or substituted or unsubstituted aromatic ring; Preferably, R1 and R2 are independently selected from C1-C6 straight chain or branched or substituted or unsubstituted phenyl groups; Preferably, R1 and R2 are independently selected from methyl, ethyl, propyl, isopropyl, butyl, benzene ring or phenethyl.

4. A method for preparing a heterocyclic polyol acid compound, characterized in that: include: A heterocyclic compound and a compound M are subjected to an amidation reaction, wherein the heterocyclic group of the heterocyclic compound has at least two substitution chains, and each of the substitution chains has at least one active group, and the compound M contains an amino group and a carboxyl group, and also contains a hydroxyl group and / or a thiol group, and at least one amino group on the compound M undergoes the amidation reaction with the active group.

5. The method for preparing the heterocyclic polyol acid compound according to claim 4, characterized in that: The compound M has a structure shown in Formula II: Wherein, R includes a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and X includes oxygen or sulfur; Preferably, the compound M includes at least one of 2-amino-4-hydroxybenzoic acid, 4-amino-3-hydroxybenzoic acid, 2-amino-3-p-hydroxyphenylpropionic acid, 2-amino-3-hydroxypropionic acid, 2-amino-3-mercaptopropionic acid and 2-amino-3-hydroxybutyric acid.

6. The method for preparing a heterocyclic polyol acid compound according to claim 4, characterized in that: The heterocyclic compound has a structure shown in Formula III, R4-Y-R3 III Wherein, Y comprises a substituted or unsubstituted heterocyclic group, and R3 and R4 are independently selected from an ester group or an acyl chloride group; Preferably, Y comprises a furan group, a tetrahydrofuran group, a pyrrole group, a pyridine group, a piperidine group, a thiophene group, an imidazole group or a pyrazine group; More preferably, the heterocyclic compound includes at least one of 2,5-pyrrole dicarboxylic acid chloride, 2,5-tetrahydrofuran dimethyl ester, 2,5-furan dicarboxylic acid chloride, 2,5-thiophene dicarboxylic acid chloride, 4,6-pyrimidine dicarboxylic acid chloride and 2,6-pyridine dicarboxylic acid chloride.

7. The method for preparing a heterocyclic polyol acid compound according to claim 4, characterized in that: The heterocyclic compound and compound M are uniformly dispersed in a solvent to form a mixed reaction liquid, and the pH of the mixed reaction liquid is adjusted to 7 to 8.5, and the amidation reaction is carried out at a temperature of 0 to 50° C. to obtain the heterocyclic polyol acid compound; Preferably, the heterocyclic compound is uniformly dispersed in a first solvent to form a solution A, the compound M is uniformly dispersed in a second solvent to form a solution B, and the solution A and the solution B are uniformly mixed to obtain the mixed reaction liquid; the first solvent and the second solvent are independently selected from at least one of water, chloroform, dichloroethane, carbon tetrachloride, ethanol, tetrahydrofuran, acetone, dichloromethane, N,N-dimethylformamide and dimethyl sulfoxide.

8. The method for preparing the heterocyclic polyol acid compound according to claim 7, characterized in that: In the mixed reaction liquid, the molar ratio of the heterocyclic compound to the compound M is 1:2 to 1:10; preferably, the molar ratio of the heterocyclic compound to the compound M is 1:2 to 1:4; And / or, the reaction time of the amidation reaction is 1 to 10 hours; And / or, after the amidation reaction is completed, the reaction product is post-treated, and the post-treatment includes: first adjusting the pH of the reaction product to 4-5 with acid, and then purifying it.

9. The derivative of the heterocyclic polyol acid compound according to any one of claims 1 to 3, wherein the derivative comprises at least one of a salt, an ester and an amide.

10. Use of the heterocyclic polyol acid compound according to any one of claims 1 to 3 in the preparation of a polyurethane chain extender or as a polyurethane chain extender; Preferably, the application includes: A mixed reaction system comprising isocyanate, polyol, solvent and chain extender is reacted to prepare waterborne polyurethane; wherein the chain extender comprises the heterocyclic polyol acid compound according to any one of claims 1 to 3.

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