An oxazole-2,4-dicarboxylic acid ethyl ester polymer, its preparation method, and its application.

Abstract

This application discloses an oxazole-2,4-dicarboxylate ethyl polymer, its preparation method, and its applications. The oxazole-2,4-dicarboxylate ethyl polymer has the structure shown in Formula I. The oxazole-2,4-dicarboxylate ethyl polymer provided in this application has a rigid oxazole ring in its main chain, which can support the sustainable development of high-performance bio-based polyester materials.

Description

Technical Field

[0001] This application relates to an oxazole-2,4-dicarboxylic acid ethyl ester polymer, its preparation method, and its application, belonging to the field of polymer materials technology. Background Technology

[0002] Petrochemical resources, as non-renewable resources, have limited reserves and cannot meet the ever-increasing demand for energy and chemicals. Furthermore, the large-scale exploitation of petrochemical resources has led to a severe energy crisis and environmental problems. Therefore, using renewable resources as raw materials to synthesize novel bio-based chemicals to replace petroleum-based chemicals, and finding and developing new bio-based polymer materials, are of significant practical importance for alleviating the energy crisis caused by petrochemical resources, solving environmental pollution problems, and achieving high-value utilization of biomass resources. In the field of polymers, terephthalic acid-based polyesters, such as polyethylene terephthalate (PET), polypropylene terephthalate (PTT), polybutylene terephthalate (PBT), and their derived copolyesters, possess excellent mechanical properties, thermal stability, and processability. They are a class of high-performance bulk polymer materials widely used in fibers, films, plastic bottles, packaging, engineering plastics, and many other fields. However, because terephthalic acid is a non-renewable raw material derived from petrochemicals, the sustainable development of its polyester materials is greatly limited. Therefore, developing bio-based polyester monomers to replace petroleum-based feedstocks has become an important research direction in the field of polyester materials.

[0003] Currently, the main chains of commonly used bio-based polyesters on the market are mainly aliphatic chain structures, such as PBS, PLA and PHA, which result in poor barrier properties and heat resistance, making it difficult for them to compete with existing petroleum-based polyesters. Summary of the Invention

[0004] To address the current limitations of limited variety and poor overall performance of bio-based polyester materials, this application proposes the development of a series of novel copolyesters composed of ethyl oxazole-2,4-dicarboxylate and aliphatic diols. These copolyesters feature a rigid oxazole ring in their polymer backbone, providing support for the sustainable development of high-performance bio-based polyester materials.

[0005] This application uses ethyl oxazole-2,4-dicarboxylate and aliphatic diols as raw materials to prepare a polymer with a rigid oxazole ring in the main chain structure, which has good mechanical properties.

[0006] This application focuses on oxazole-2,4-dicarboxylic acid ethyl ester and utilizes various aliphatic diols to develop a series of novel bio-based copolyester materials with oxazole rigid rings.

[0007] According to one aspect of this application, an oxazole-2,4-dicarboxylate ethyl ester polymer is provided, said oxazole-2,4-dicarboxylate ethyl ester polymer having the structure shown in Formula I:

[0008]

[0009] In Formula I, R is selected from one of C2-C10 alkyl groups and C3-C10 cycloalkyl groups;

[0010] n is an integer, and its value ranges from 1 to 550.

[0011] Optionally, R is selected from -CH2-CH2-, -CH2-CH2-CH2-, -CH2-CH2-CH2-CH2-, -CH2-CH2-CH2-CH2-CH2-CH 2- , At least one of them.

[0012] According to another aspect of this application, a method for preparing the above-described oxazole-2,4-dicarboxylic acid ethyl ester polymer is provided, the method comprising:

[0013] Under an inactive atmosphere, a mixture containing ethyl oxazole-2,4-dicarboxylate, an aliphatic diol, and a catalyst is subjected to reaction I, followed by reaction II with increased temperature, to obtain the ethyl oxazole-2,4-dicarboxylate polymer.

[0014] Optionally, the aliphatic diol is selected from at least one of ethylene glycol, propylene glycol, butanediol, hexanediol, and 1,4-cyclohexanediethanol.

[0015] Optionally, the catalyst is selected from at least one of tetrabutyl titanate, isopropyl titanate, stannous octoate, zinc acetate, and antimony acetate.

[0016] Optionally, the molar ratio of oxazole-2,4-dicarboxylate to the aliphatic diol is 1:5 to 5:1.

[0017] Optionally, the mass of the catalyst is 0.5‰ to 1% of the mass of the oxazole-2,4-dicarboxylate.

[0018] Optionally, the mass of the catalyst is independently selected from any value of 0.5‰, 1‰, 2‰, 3‰, 5‰, 8‰, 9‰, 1% or a range between any two of the above.

[0019] Optionally, the temperature of reaction I is 90–210°C, and the reaction time is 0.5–4 h.

[0020] Optionally, the temperature of reaction I is independently selected from any value of 90°C, 100°C, 120°C, 150°C, 180°C, 200°C, 210°C, or a range between any two of the above.

[0021] Optionally, the reaction time I is independently selected from any value among 0.5h, 1h, 2h, 3h, 4h or a range between any two of the above.

[0022] Optionally, the temperature of reaction II is 170–260°C, and the reaction time is 0.5–4 h.

[0023] Optionally, the temperature of reaction II is independently selected from any value of 170°C, 190°C, 200°C, 210°C, 220°C, 240°C, 260°C, or a range between any two of the above.

[0024] Optionally, the reaction time of reaction II is independently selected from any value of 0.5h, 1h, 2h, 3h, 4h or a range between any two of the above.

[0025] Optionally, the inactive atmosphere is selected from at least one of nitrogen, argon, and carbon dioxide.

[0026] According to another aspect of this application, the use of the above-described oxazole-2,4-dicarboxylate polymer in polyester materials is provided.

[0027] As an optional implementation, this application is achieved through the following technical solution:

[0028] The preparation method of oxazole-2,4-dicarboxylic acid ethyl ester and aliphatic diol copolyester includes the following steps:

[0029] Step 1: Under an inert gas atmosphere, ethyl oxazole-2,4-dicarboxylate, aliphatic diol and catalyst are transesterified at a certain temperature to obtain a prepolymer;

[0030] Step 2: The prepolymer obtained in Step 1 is heated and vacuumed. Under high temperature and high vacuum, oxazole-2,4-dicarboxylic acid ethyl ester and aliphatic diol copolyester are obtained.

[0031] In this application, C2 to C10 and C6 to C10 refer to the number of carbon atoms contained in the group.

[0032] In this application, the term "alkyl" refers to a group formed by the loss of any one hydrogen atom from an alkane molecule.

[0033] In this application, the term "cycloalkyl" refers to a group formed by the loss of any one hydrogen atom from a cycloalkane molecule.

[0034] The beneficial effects that this application can produce include:

[0035] The oxazole-2,4-dicarboxylic acid ethyl ester and aliphatic diol copolyester provided in this application has a large number of oxazole rings in its main chain. The oxazole rings have high rigidity, which can provide good mechanical properties. This material can support the sustainable development of high-performance bio-based polyester materials. Detailed Implementation

[0036] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0037] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0038] Example 1

[0039] 6g of oxazole-2,4-dicarboxylic acid ethyl ester, 1.8g of ethylene glycol and 1mg of antimony acetate were mixed and heated to 120℃ for 1h under a nitrogen atmosphere. Then the temperature was raised to 240℃ and the reaction was carried out under vacuum for 3h using an oil pump to obtain polyoxazole-2,4-dicarboxylic acid ethylene glycol ester.

[0040] Example 2

[0041] 6g of oxazole-2,4-dicarboxylic acid ethyl ester, 2.2g of propylene glycol and 1mg of antimony acetate were mixed and heated to 120℃ for 1h under a nitrogen atmosphere. Then the temperature was raised to 240℃ and the reaction was carried out under vacuum for 3h using an oil pump to obtain polyoxazole-2,4-dicarboxylic acid propylene glycol ester.

[0042] Example 3

[0043] 6g of oxazole-2,4-dicarboxylate, 2.6g of butanediol and 1mg of antimony acetate were mixed and heated to 120℃ for 1h under a nitrogen atmosphere. Then the temperature was raised to 240℃ and the reaction was carried out under vacuum for 3h using an oil pump to obtain polyoxazole-2,4-dicarboxylate.

[0044] Example 4

[0045] 6g of oxazole-2,4-dicarboxylic acid ethyl ester, 3.4g of hexanediol and 1mg of antimony acetate were mixed and heated to 120℃ for 1h under a nitrogen atmosphere. Then the temperature was raised to 240℃ and the reaction was carried out under vacuum for 3h using an oil pump to obtain polyoxazole-2,4-dicarboxylic acid hexanediol ester.

[0046] Example 5

[0047] 6g of oxazole-2,4-dicarboxylic acid ethyl ester, 4.2g of 1,4-cyclohexanediethanol and 1mg of antimony acetate were mixed and heated to 120℃ for 1h under a nitrogen atmosphere. Then the temperature was raised to 240℃ and the reaction was carried out under vacuum for 3h using an oil pump to obtain polyoxazole-2,4-dicarboxylic acid-1,4-cyclohexanediethanol ester.

[0048] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. An oxazole-2,4-dicarboxylic acid ethyl ester polymer, characterized in that, The oxazole-2,4-dicarboxylic acid ethyl ester polymer has the structure shown in Formula I: Equation I; In Formula I, R is selected from -CH2-CH2-, -CH2-CH2-CH2-, -CH2-CH2-CH2-CH2-, -CH2-CH2-CH2-CH2-CH2-CH 2- , At least one of them; n is an integer, and the value of n ranges from 1 to 550, excluding 1.

2. The method for preparing the oxazole-2,4-dicarboxylic acid ethyl ester polymer according to claim 1, characterized in that, The preparation method includes: In an inactive atmosphere, a mixture containing ethyl oxazole-2,4-dicarboxylate, an aliphatic diol, and a catalyst is reacted at 90-210°C for 0.5-4 h, and then the temperature is raised to 170-260°C for another 0.5-4 h to obtain the ethyl oxazole-2,4-dicarboxylate polymer.

3. The preparation method according to claim 2, characterized in that, The aliphatic diol is selected from at least one of ethylene glycol, propylene glycol, butanediol, hexanediol, and 1,4-cyclohexanediethanol.

4. The preparation method according to claim 2, characterized in that, The catalyst is selected from at least one of tetrabutyl titanate, isopropyl titanate, stannous octoate, zinc acetate, and antimony acetate.

5. The preparation method according to claim 2, characterized in that, The molar ratio of ethyl oxazole-2,4-dicarboxylate to the aliphatic diol is 1:5 to 5:

1.

6. The preparation method according to claim 2, characterized in that, The mass of the catalyst is 0.5‰ to 1% of the mass of the oxazole-2,4-dicarboxylic acid ethyl ester.

7. The preparation method according to claim 2, characterized in that, The inactive atmosphere is selected from at least one of nitrogen, argon, and carbon dioxide.

8. The application of the oxazole-2,4-dicarboxylic acid ethyl ester polymer according to claim 1 in polyester materials.

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