阅读说明：本技术 一种韧性2,5-噻吩二甲酸基共聚酯材料及其制备方法 (Tough 2, 5-thiophene diformyl copolyester material and preparation method thereof ) 是由 周光远 姜敏 王国强 于 2020-03-20 设计创作，主要内容包括：本发明提供一种韧性的2,5-噻吩二甲酸基共聚酯材料及其制备方法。该材料的结构式如式(1)和(2)所示。本发明还提供一种韧性2,5-噻吩二甲酸基共聚酯材料的制备方法。本发明将1,5-戊二醇,与2,5-噻吩二甲酸或2,5-噻吩二甲酸二酯类化合物、HO-R-OH进行直接酯化或酯交换反应,制备了高韧性(断裂伸长率>500％)、高拉伸强度(>50Mpa)、高生物降解率(>70％)的共聚酯材料,有利于扩大2,5-噻吩二甲酸基聚酯材料的在使用范围。(The invention provides a tough 2, 5-thiophene diformyl copolyester material and a preparation method thereof. The structural formula of the material is shown as formulas (1) and (2). The invention also provides a preparation method of the tough 2, 5-thiophene diformyl copolyester material. According to the invention, 1, 5-pentanediol, 2, 5-thiophenedicarboxylic acid or 2, 5-thiophenedicarboxylic acid diester compound and HO-R-OH are subjected to direct esterification or ester exchange reaction to prepare the copolyester material with high toughness (elongation at break > 500%), high tensile strength (>50Mpa) and high biodegradation rate (> 70%), so that the application range of the 2, 5-thiophenedicarboxylic acid based polyester material can be expanded.)

1. A2, 5-thiophene diformate-based copolyester material is characterized by consisting of structural units represented by the following general formula (1) and general formula (2), wherein the general formula (1) and the general formula (2) are represented as follows:

formula R is-CH₂-CH₂-，-CH₂-CH₂-CH₂-at least one or more of.

2. A method for preparing the 2, 5-thiophenedicarboxylic acid based copolyester material according to claim 1, comprising the steps of:

the method comprises the following steps: under the action of a catalyst, carrying out direct esterification or ester exchange reaction on the raw materials A and B and HO-R-OH diol to obtain a prepolymer; the raw material A is at least one of 2, 5-thiophenedicarboxylic acid or 2, 5-thiophenedicarboxylic acid diester compounds, and the raw material B is 1, 5-pentanediol;

step two: and (3) vacuumizing the prepolymer obtained in the step one to perform polycondensation reaction to obtain the 2, 5-thiophene diformyl copolyester material.

3. The method as claimed in claim 2, wherein the temperature of the direct esterification or ester exchange reaction in the first step is 100-300 ℃, and the reaction time is 1-10 hours;

the polycondensation reaction temperature in the second step is 100-300 ℃, the vacuum degree is 5-150Pa, and the reaction time is 1-10 hours.

4. The method for preparing copolyester material according to claim 2, wherein the catalyst in the first step is antimony, tin, germanium or titanium catalyst.

5. The preparation method according to claim 4, wherein the antimony catalyst is antimony trioxide, ethylene glycol antimony or antimony acetate;

the tin catalyst is stannous oxide, stannous octoate, stannous chloride, stannous bromide, stannous iodide, stannous acetate, stannous oxalate, stannous sulfate or stannous hydroxide;

the titanium catalyst is tetrabutyl titanate, isopropyl titanate or tetraethyl titanate;

the germanium catalyst is germanium dioxide.

6. The method according to claim 2, wherein the 2, 5-thiophenedicarboxylic acid diester compound is at least one of dimethyl 2, 5-thiophenedicarboxylate, diethyl 2, 5-thiophenedicarboxylate, dipropyl 2, 5-thiophenedicarboxylate, and dibutyl 2, 5-thiophenedicarboxylate.

7. The preparation method according to claim 2, wherein the molar ratio of the total molar amount of the raw material B and the HO-R-OH diol to the raw material A in the first step is 10: 1 to 100.

8. The process according to claim 2, wherein the molar ratio between starting material B and HO-R-OH diol is between 0.01 and 0.99: 0.99-0.01; the mass ratio of the catalyst to the raw material A is 1:10000-1: 200.

9. Use of the 2, 5-thiophenedicarboxylic acid based copolyester material according to claim 1.

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a tough 2, 5-thiophene diformyl copolyester material and a preparation method thereof.

Background

Due to the shortage of petroleum resources, the bio-based polyester materials synthesized from biomass resources are receiving more and more attention from people. The literature reports that 2, 5-thiophenedicarboxylic acid can be synthesized from adipic acid by reaction with thionyl chloride (Fluid Phase Equil.2014,375110-114 and Thermochim.acta.2014, 59252-57). Adipic acid can be synthesized from biomass resources, glucaric acid or muconic acid (J.Biotechnol.2013, 16775-84). Thus, 2, 5-thiophenedicarboxylic acid is a monomer derived from biomass resources.

Polyesters synthesized on the basis of 2, 5-thiophenedicarboxylic acid and aliphatic diols (ethylene glycol or 1, 3-propanediol or 2-methyl-1, 3-propanediol) have limited their use due to their poor toughness (eXPRESS Polymer Letters,2019,11: 938-947, Polymer,2019,173: 27-33 and Polymer Degradation and Stability,2019,168: 108942/1-108942/8). Although it was previously possible to improve the toughness by copolymerizing terephthalic acid with the above monomers, terephthalic acid is a petroleum-based monomer and the synthesis process is environmentally polluting, limiting its application (Polymer.2019,173: 27-33).

Disclosure of Invention

The invention aims to provide a tough 2, 5-thiophene diformic acid based copolyester material and a preparation method thereof, wherein the main synthetic monomer of the material is derived from biomass resources, and the toughness of the polyester can be improved by adopting a random copolyester synthesized by copolymerizing 1, 5-pentanediol which can be derived from the biomass resources, 2, 5-thiophene diformic acid and glycol (at least one of ethylene glycol and 1, 3-propylene glycol). The invention provides a 2, 5-thiophene diformate copolyester material, which consists of structural units represented by the following general formula (1) and general formula (2), wherein the general formula (1) and the general formula (2) are shown as follows:

formula R is-CH₂-CH₂-，-CH₂-CH₂-CH₂-at least one of.

The invention also provides a preparation method of the 2, 5-thiophene diformyl copolyester material, which comprises the following steps:

the method comprises the following steps: under the action of a catalyst, carrying out direct esterification or ester exchange reaction on the raw materials A and B and HO-R-OH diol to obtain a prepolymer; the raw material A is at least one of 2, 5-thiophenedicarboxylic acid or 2, 5-thiophenedicarboxylic acid diester compounds, and the raw material B is 1, 5-pentanediol;

step two: and (3) vacuumizing the prepolymer obtained in the step one to perform polycondensation reaction to obtain the 2, 5-thiophene diformyl copolyester material.

Based on the above technical scheme, preferably, the direct esterification or ester exchange reaction temperature in the step one is 100-300 ℃, and the reaction time is 1-10 hours;

the polycondensation reaction temperature in the second step is 100-300 ℃, the vacuum degree is 5-150Pa, and the reaction time is 1-10 hours.

Based on the technical scheme, the catalyst in the first step is preferably an antimony catalyst, a tin catalyst, a germanium catalyst or a titanium catalyst.

Based on the technical scheme, preferably, the antimony catalyst is antimony trioxide, ethylene glycol antimony or antimony acetate;

the tin catalyst is stannous oxide, stannous octoate, stannous chloride, stannous bromide, stannous iodide, stannous acetate, stannous oxalate, stannous sulfate or stannous hydroxide;

the titanium catalyst is tetrabutyl titanate, isopropyl titanate or tetraethyl titanate;

the germanium catalyst is germanium dioxide;

based on the technical scheme, the 2, 5-thiophene dicarboxylic acid diester compound is preferably at least one of 2, 5-thiophene dicarboxylic acid dimethyl ester, 2, 5-thiophene dicarboxylic acid diethyl ester, 2, 5-thiophene dicarboxylic acid dipropyl ester or 2, 5-thiophene dicarboxylic acid dibutyl ester.

Based on the technical scheme, the molar ratio of the total molar amount of the raw material B and the HO-R-OH diol to the raw material A in the step one is preferably 10: (1-100).

Based on the technical scheme, the molar ratio of the raw material B to the HO-R-OH diol is preferably 0.01-0.99: 0.99-0.01; the mass ratio of the catalyst to the raw material A is 1:10000-1: 200.

The invention also provides application of the 2, 5-thiophenedicarboxylic acid based copolyester material, which can be used as a material for bottles, films, fibers, sheets, packages and optical products.

Advantageous effects

(1) The invention provides a high-toughness 2, 5-thiophene diformyl copolyester material, the structural formula of the material is shown in general formulas (1) and (2), and 1, 5-pentanediol with five flexible methylene structures is introduced into the structure, so that the flexibility of polyester can be increased, and the glass transition temperature of the polyester can be reduced. Meanwhile, 1, 5-pentanediol is an odd-numbered diol, and 1, 5-pentanediol is not favorable for polyester crystallization due to an odd-even effect. Therefore, the 1, 5-pentanediol can reduce the glass transition temperature and the crystallinity of the polyester, improve the elongation at break and the toughness of the 2, 5-thiophene diformyl polyester and expand the application range of the polyester.

(2)1, 5-pentanediol can be obtained from biomass resources, has wider sources than other petroleum-based monomers, and is more environment-friendly in the production process. Therefore, the invention can improve the utilization of biomass resources and is more beneficial to environmental protection.

(3) After the odd carbon and long chain 1, 5-pentanediol is introduced into the polyester chain, the polyester chain is more easily biodegraded, so that the toughness is improved, and the biodegradability of the polyester is also improved.

Drawings

FIG. 1 is an infrared spectrum of a copolyester prepared in example 1 of the present invention.

FIG. 2 is an infrared spectrum of the copolyester prepared in comparative example 1.

Detailed Description

Example 1

(1) Under the action of stannous octoate, 2, 5-thiophenedicarboxylic acid, 1, 5-pentanediol and ethylene glycol were added to a reaction flask, and the molar ratio of total diols (1, 5-pentanediol and ethylene glycol) and 2, 5-thiophenedicarboxylic acid was 1.6: the molar ratio of 1, 1, 5-pentanediol to ethylene glycol was 0.25: 0.75. and stannous octoate accounts for 0.3 percent of the mass of diacid, and the mixture is stirred and reacted for 3 hours at 200 ℃ under the protection of nitrogen to generate a prepolymer.

(2) And vacuumizing the prepolymer to 5Pa, and stirring and reacting at 245 ℃ for 1h to obtain the copolyester. The material has structural units represented by the following general formulae (1) and (2):

formula R is-CH₂-CH₂-。

The IR spectrum of the copolyester prepared in example 1 is shown in FIG. 1, and CH is compared with the IR spectrum 2 of comparative example 1₂Peak of asymmetric stretching vibration and symmetric stretching vibration of CH (2963 cm)^-1And 2863cm^-1) The strength increased, demonstrating the synthesis of a copolyester of 2, 5-thiophenedicarboxylic acid, 1, 5-pentanediol, and ethylene glycol.

Tensile property test conditions: the test was carried out according to ASTM D-638, dumbbell type specimen (size of middle test portion: width: 3.18mm, thickness: 3.20mm), tensile rate: 5 mm/min. The tensile properties are shown in Table 1. The prepared bio-based copolyester is subjected to composting degradation for 90 days according to the method of American ASTM6400, and the biological decomposition rate is shown in Table 1.

Example 2

(1) Under the action of ethylene glycol antimony, adding dimethyl 2, 5-thiophenedicarboxylate, 1, 5-pentanediol and 1, 3-propanediol into a reaction bottle, wherein the molar ratio of total diols (1, 5-pentanediol and 1, 3-propanediol) to dimethyl 2, 5-thiophenedicarboxylate is 1.6: the molar ratio of the 1, 1, 5-pentanediol to the 1, 3-propanediol is 0.2: 0.8. ethylene glycol antimony accounts for 0.3 percent of the diester by mass, and the reaction is carried out for 3 hours at 200 ℃ under the protection of nitrogen gas by stirring to generate a prepolymer.

(2) And vacuumizing the prepolymer to 5Pa, and stirring and reacting at 245 ℃ for 8 hours to obtain the copolyester. The material has structural units represented by the following general formulas (1) and (2), and the structural formulas are represented by the formulas (1) and (2):

formula R is-CH₂-CH₂-CH₂-；

Tensile property test conditions: the same as in example 1. The tensile properties are shown in Table 1. The prepared bio-based copolyester is subjected to composting degradation for 90 days according to the method of American ASTM6400, and the biological decomposition rate is shown in Table 1.

Example 3

(1) Adding 2, 5-thiophenedicarboxylic acid, 1, 5-pentanediol and ethylene glycol into a reaction bottle under the action of tetrabutyl titanate, wherein the molar ratio of total glycol (1, 5-pentanediol and ethylene glycol) to dimethyl 2, 5-thiophenedicarboxylate is 3: the molar ratio of 1, 1, 5-pentanediol to ethylene glycol is 0.3: 0.7. tetrabutyl titanate accounts for 0.3 percent of the mass percent of the 2, 5-thiophenedicarboxylic acid, and is stirred and reacted for 3 hours at 200 ℃ under the protection of nitrogen to generate a prepolymer.

(2) And vacuumizing the prepolymer to 150Pa, and stirring and reacting at 240 ℃ for 10 hours to obtain the copolyester. The material has structural units represented by the following general formulas (1) and (2), and the structural formulas are represented by the formulas (1) and (2):

formula R is-CH₂-CH₂-。

Tensile property test conditions: the same as in example 1. The tensile properties are shown in Table 1. The prepared bio-based copolyester is subjected to composting degradation for 90 days according to the method of American ASTM6400, and the biological decomposition rate is shown in Table 1.

Comparative example 1

(1) Under the action of stannous octoate, adding 2, 5-thiophene dimethyl dicarboxylate and ethylene glycol into a reaction bottle, wherein the molar ratio of the ethylene glycol to the 2, 5-thiophene dimethyl dicarboxylate is 3: 1, stannous octoate accounts for 0.3 percent of the mass of the diester, and the mixture is stirred and reacted for 3 hours at 200 ℃ under the protection of nitrogen to generate a prepolymer.

(2) And vacuumizing the prepolymer to 80Pa, and stirring and reacting at 245 ℃ for 8h to obtain the polyethylene glycol 2, 5-thiophene dicarboxylate (PETF).

The infrared spectrum of the copolyester prepared in comparative example 1 is shown in fig. 2.

Tensile property test conditions: the same as in example 1. The tensile properties are shown in Table 1. The prepared bio-based copolyester is subjected to composting degradation for 90 days according to the method of American ASTM6400, and the biological decomposition rate is shown in Table 1.

Comparative example 2

(1) Under the action of ethylene glycol antimony, adding 2, 5-thiophene dimethyl dicarboxylate and 1, 3-propylene glycol into a reaction bottle, wherein the molar ratio of the 1, 3-propylene glycol to the 2, 5-thiophene dimethyl dicarboxylate is 3: and 1, ethylene glycol antimony accounts for 0.3 percent of the diester by mass, and the mixture is stirred and reacted for 3 hours at 200 ℃ under the protection of nitrogen to generate a prepolymer.

(2) Vacuumizing the prepolymer to 80Pa, stirring at 245 ℃ and reacting for 8h to obtain the poly-1, 3-propylene glycol 2, 5-thiophenedicarboxylate (PTTF).

Tensile property test conditions: the same as in example 1. The tensile properties are shown in Table 1. The prepared bio-based copolyester is subjected to composting degradation for 90 days according to the method of American ASTM6400, and the biological decomposition rate is shown in Table 1.

Comparative example 3

(1) Under the action of germanium dioxide, adding dimethyl 2, 5-thiophenedicarboxylate, 2, 2-dimethyl-1, 3-propanediol and 1, 6-hexanediol into a reaction bottle, wherein the molar ratio of total diol (2, 2-dimethyl-1, 3-propanediol and 1, 6-hexanediol) to dimethyl 2, 5-thiophenedicarboxylate is 3: the molar ratio of 1, 1, 6-hexanediol to 2, 2-dimethyl-1, 3-propanediol is 0.2: 0.8. germanium dioxide accounts for 0.3 percent of the diester by mass, and the mixture is stirred and reacted for 3 hours at 200 ℃ under the protection of nitrogen to generate a prepolymer.

(2) And vacuumizing the prepolymer to 80Pa, stirring at 245 ℃ and reacting for 8 hours to obtain the 2, 5-thiophene diformyl copolyester.

Tensile property test conditions: the same as in example 1. The tensile properties are shown in Table 1. The prepared bio-based copolyester is subjected to composting degradation for 90 days according to the method of American ASTM6400, and the biological decomposition rate is shown in Table 1.

As can be seen from table 1, with the introduction of the bio-based monomer 1, 5-pentanediol, the elongation at break increased 526.1% for example 1 compared to comparative example 1 and 541.5% for example 2 compared to comparative example 2, demonstrating that: the introduction of 1, 5-pentanediol can significantly increase the toughness. The tensile strength, elongation at break and biodegradation rates of examples 1-3 were significantly higher compared to comparative example 3. And (3) proving that: the introduction of 1, 5-pentanediol can obviously increase the toughness and the biodegradation rate while keeping high tensile strength.

TABLE 12 mechanical Properties and biodegradation rates of 5-thiophenedicarboxylic acid-based polyesters