阅读说明：本技术 一种含二硫键的二元醇、制备方法及其应用 (Disulfide bond-containing dihydric alcohol, and preparation method and application thereof ) 是由 李燕平 张晓超 李红仙 刘阳 左洪亮 陈炳琳 黄杰 于 2020-12-22 设计创作，主要内容包括：本发明涉及二元醇技术领域,更具体地,本发明涉及一种含二硫键的二元醇、制备方法及其应用；所述含二硫键的二元醇,其结构如式(1)所示,式(1)如下：所述含二硫键的二元醇的制备原料包括式(2)所示的化合物和过氧化物；式(2)如下：本发明在制备含二硫键的二元醇的过程中,采用廉价的原料,不使用催化剂,采用一锅法反应,工艺简洁、操作方便,易于实施；采用微通道混合反应器,避免了过多聚醚副产物的生成,提高了纯度；同时本发明规避了使用多硫化物构建二硫键所导致的产品纯度问题；本发明中的含二硫键的二元醇可应用于聚酯、聚氨酯等材料领域,用于提升材料性能。(The invention relates to the technical field of dihydric alcohol, in particular to a dihydric alcohol containing disulfide bonds, a preparation method and application thereof; the structure of the diol containing the disulfide bond is shown as a formula (1), wherein the formula (1) is as follows: the preparation raw materials of the dihydric alcohol containing the disulfide bond comprise a compound shown as a formula (2) and peroxide; the formula (2) is as follows:)

1. The diol containing the disulfide bond is characterized by having a structure shown as a formula (1), wherein the formula (1) is as follows:

the preparation raw materials of the dihydric alcohol containing the disulfide bond comprise a compound shown as a formula (2) and peroxide; the formula (2) is as follows:

wherein in the formula (1) and the formula (2), R is selected from any one of hydrogen, alkyl of C1-C12 and aryl of C6-C10.

2. The disulfide bond-containing diol according to claim 1, wherein the molar ratio of the peroxide to the compound represented by formula (2) is (0.5 to 1.1): 1.

3. the disulfide bond-containing diol according to claim 1 or 2, wherein the compound represented by the formula (2) is prepared from a starting material comprising an alkali metal hydrosulfide solution and an epoxide solution; the epoxide structure in the epoxide solution is as follows:

wherein R is selected from any one of hydrogen, alkyl of C1-C12 and aryl of C6-C10.

4. The disulfide bond-containing diol according to claim 3, wherein the molar ratio of alkali metal hydrosulfide in the alkali metal hydrosulfide solution to epoxide in the epoxide solution is (1.1-2): 1.

5. the disulfide bond-containing diol according to claim 3, wherein the concentration of the alkali metal hydrosulfide solution is 1 to 20 wt%.

6. The disulfide bond-containing diol according to claim 3, wherein the concentration of the epoxide solution is 1 to 20 wt%.

7. The diol containing disulfide bond according to any one of claims 4 to 6, wherein the solvent of the alkali metal hydrosulfide solution is an organic solvent and/or water, preferably the solvent of the alkali metal hydrosulfide solution is an organic solvent and water, and the weight ratio of the organic solvent to the water is (5-10): 1.

8. a method for producing the disulfide bond-containing diol according to any one of claims 1 to 7, which comprises: mixing the compound shown in the formula (2) with peroxide, reacting at 30-80 ℃ for 1-4h to obtain a reaction solution, adjusting the reaction solution to be neutral, removing the solvent, and distilling to obtain the compound.

9. The method for producing a disulfide bond-containing diol according to claim 8, wherein the method for producing a compound represented by the formula (2) comprises: pumping the alkali metal hydrosulfide solution and the epoxide solution into a micro-channel mixer, and reacting at 40-120 ℃ to obtain the catalyst.

10. Use of a diol containing a disulfide bond according to any one of claims 1 to 7 in the preparation of polyesters, polyurethanes, surfactants.

Technical Field

The invention relates to the technical field of dihydric alcohol, and in particular relates to a dihydric alcohol containing a disulfide bond, a preparation method and application thereof.

Background

At present, glycol compounds are important organic chemical raw materials in industry, such as ethylene glycol, which can be used for producing polyester plastics, polyester fibers and polyethylene terephthalate, and can also be used as raw materials of chemical products such as surfactants, plasticizers and the like. The 1, 4-Butanediol (BDO) can be used for producing products such as Tetrahydrofuran (THF), gamma-butyrolactone (GBL) and the like, can be used for preparing dibutyl terephthalate (PBT) with terephthalic acid, is an excellent engineering plastic, and can be widely applied to industries such as automobiles, machinery, electronic and electric appliances and the like. Other diol compounds such as 1, 3-propylene glycol (PDO) and 1, 4-Cyclohexanedimethanol (CHDM) are also important basic chemical raw materials, and are widely used in the fields of polyester and polyurethane, and therefore, the diol compounds, especially diols with special structures, have been considered to be highly important.

The sulfur bond (-S-S-) widely exists in nature and plays an important role in maintaining the tertiary structure of the protein. In the field of materials, compounds containing disulfide bonds can be used as energy storage and self-repair materials; the polyimide containing disulfide bonds can remarkably improve the performance reliability of the material and can be used as a reversible crosslinking material. The invention patent CN106397755A discloses a method for preparing polyester polyol containing disulfide bonds, and the polyol is applied to the field of polyurethane, which has very important significance for improving the performance of polyurethane materials. The invention patent CN107721892A discloses a thiopolythiol and application thereof in polyurethane, and a polyurethane material with high light transmittance, high refractive index and high hardness and stable chemical properties can be prepared. However, at present, the preparation process of the dihydric alcohol containing the disulfide bond is complicated, the raw materials are expensive, and the yield and the purity of the prepared dihydric alcohol containing the disulfide bond can not meet the requirements of people.

Disclosure of Invention

In view of the problems in the prior art, the first aspect of the present invention provides a diol containing disulfide bonds, which has the structure shown in formula (1), wherein formula (1) is as follows:

the preparation raw materials of the dihydric alcohol containing the disulfide bond comprise a compound shown as a formula (2) and peroxide; the formula (2) is as follows:

wherein in the formula (1) and the formula (2), R is selected from any one of hydrogen, alkyl of C1-C12 and aryl of C6-C10.

As a preferable embodiment of the present invention, the molar ratio of the peroxide to the compound represented by the formula (2) is (0.5 to 1.1): 1.

as a preferable technical scheme of the invention, the preparation raw materials of the compound shown in the formula (2) comprise alkali metal hydrosulfide solution and epoxide solution; the epoxide structure in the epoxide solution is as follows:

wherein R is selected from any one of hydrogen, alkyl of C1-C12 and aryl of C6-C10.

As a preferable technical scheme of the invention, the molar ratio of the alkali metal hydrosulfide in the alkali metal hydrosulfide solution to the epoxide in the epoxide solution is (1.1-2): 1.

as a preferable embodiment of the present invention, the concentration of the alkali metal hydrosulfide solution is 1 to 20 wt%.

As a preferred embodiment of the present invention, the concentration of the epoxide solution is 1 to 20 wt%.

As a preferred technical solution of the present invention, the solvent of the alkali metal hydrosulfide solution is an organic solvent and/or water, and preferably, the solvent of the alkali metal hydrosulfide solution is an organic solvent and water, and the weight ratio of the organic solvent to the water is (5-10): 1.

the second aspect of the present invention provides a method for preparing the disulfide bond-containing diol, which comprises: mixing the compound shown in the formula (2) with peroxide, reacting at 30-80 ℃ for 1-4h to obtain a reaction solution, adjusting the reaction solution to be neutral, removing the solvent, and distilling to obtain the compound.

As a preferable embodiment of the present invention, the preparation method of the compound represented by the formula (2) comprises: pumping the alkali metal hydrosulfide solution and the epoxide solution into a micro-channel mixer, and reacting at 40-120 ℃ to obtain the catalyst.

The third aspect of the invention provides an application of the diol containing the disulfide bond in preparation of polyester, polyurethane and surfactant.

Compared with the prior art, the invention has the following beneficial effects:

in the process of preparing the dihydric alcohol containing the disulfide bond, the invention adopts cheap raw materials, does not use catalysts, adopts a one-pot reaction, and has simple process, convenient operation and easy implementation; the microchannel mixing reactor is adopted, so that the generation of excessive polyether byproducts is avoided, and the purity is improved; meanwhile, the invention avoids the problem of product purity caused by the construction of disulfide bonds by polysulfide; the dihydric alcohol containing the disulfide bond can be applied to the fields of materials such as polyester, polyurethane, surfactant and the like, and is used for improving the performance of the materials.

Detailed Description

The present invention is illustrated by the following specific embodiments, but is not limited to the specific examples given below.

The first aspect of the invention provides a diol containing a disulfide bond, which has a structure shown in a formula (1), wherein the formula (1) is as follows:

wherein R is selected from any one of hydrogen, alkyl of C1-C12 and aryl of C6-C10.

In one embodiment, the raw materials for preparing the disulfide bond-containing diol include a compound represented by formula (2) and a peroxide; the formula (2) is as follows:

wherein R is selected from any one of hydrogen, alkyl of C1-C12 and aryl of C6-C10.

Preferably, the molar ratio of the peroxide to the compound represented by formula (2) is (0.5-1.1): 1.

more preferably, the molar ratio of the peroxide to the compound represented by formula (2) is (0.6-0.8): 1.

preferably, the peroxide is selected from one or more of hydrogen peroxide, tert-butyl peroxide, m-chloroperoxybenzoic acid and peroxyacetic acid; more preferably, the peroxide is hydrogen peroxide or t-butanol peroxide.

In one embodiment, the starting materials for preparing the compound represented by the formula (2) include an alkali metal hydrosulfide solution and an epoxide solution; the epoxide structure in the epoxide solution is as follows:

wherein R is selected from any one of hydrogen, alkyl of C1-C12 and aryl of C6-C10.

The kind of the alkali metal hydrosulfide of the present invention is not particularly limited, and those skilled in the art can select it routinely.

In one embodiment, the alkali metal hydrosulfide is sodium hydrosulfide.

Preferably, the molar ratio of alkali metal hydrosulfide in the alkali metal hydrosulfide solution to epoxide in the epoxide solution is (1.1-2): 1; more preferably, the molar ratio of alkali metal hydrosulfide in the alkali metal hydrosulfide solution to epoxide in the epoxide solution is 1.3: 1.

in one embodiment, the alkali metal hydrosulfide solution has a concentration of 1 to 20 weight percent.

The concentration of the alkali metal hydrosulfide solution of the present invention is not particularly limited as long as it is in the range of 1 to 20 wt%.

Preferably, the solvent of the alkali metal hydrosulfide solution is an organic solvent and/or water, and further preferably, the solvent of the alkali metal hydrosulfide solution is an organic solvent and water, and the weight ratio of the organic solvent to the water is (3-10): 1; more preferably, the weight ratio of the organic solvent to water is 5: 1.

preferably, the organic solvent is selected from one or more of water, acetone, DMF, DMSO, acetonitrile, dioxane; more preferably, the organic solvent is acetone and/or DMF.

In one embodiment, the concentration of the epoxide solution is from 1 to 20 weight percent.

Preferably, the concentration of the epoxide solution is 13 wt%.

The solvent for the epoxide solution of the present invention is not particularly limited and may be selected conventionally by those skilled in the art.

Examples of the solvent for the epoxide solution include acetone, tetrahydrofuran, toluene, xylene, diethylene glycol dimethyl ether, and methyl t-butyl ether.

Preferably, the solvent of the epoxide solution is acetone.

At present, expensive polysulfide is used as a raw material in the preparation process of the dihydric alcohol containing the disulfide bond, but the obtained dihydric alcohol containing the disulfide bond has more impurities and cannot meet the requirements of the current industrial production. The applicant unexpectedly found that the purity of the disulfide bond-containing diol prepared by using cheap alkali metal hydrosulfide and epoxide as raw materials is higher, not less than 96%, and the applicant believes that the probable reason is that under alkaline conditions, epoxide ring-opening is carried out, so that ring-opening products with smaller steric hindrance are mainly obtained, and the purity of the disulfide bond-containing diol synthesized by the reaction with peroxide is higher. Further, the applicant has unexpectedly found that the purity of the resulting disulfide bond-containing diol is further improved when the concentration of the epoxide solution is 1 to 20 wt%, and the applicant believes that a possible reason is that under such conditions, the formation of by-product polyether may be reduced, thereby improving the purity and yield of the disulfide bond-containing diol.

In a second aspect, the present invention provides a method for preparing a disulfide bond-containing diol, comprising: mixing the compound shown in the formula (2) with peroxide, reacting at 30-80 ℃ for 1-4h to obtain a reaction solution, adjusting the reaction solution to be neutral, removing the solvent, and distilling to obtain the compound.

In one embodiment, the method of making the disulfide bond-containing diol comprises: mixing the compound shown in the formula (2) with peroxide, reacting for 2h at 50-60 ℃ to obtain reaction liquid, adjusting the reaction liquid to be neutral, removing the solvent, and distilling to obtain the compound.

In a more preferred embodiment, the method for preparing the disulfide bond-containing diol comprises: mixing the compound shown in the formula (2) with peroxide, reacting for 2h at 50 ℃ to obtain reaction liquid, adjusting the reaction liquid to be neutral, removing the solvent, and distilling to obtain the compound.

In one embodiment, the method for preparing the compound represented by formula (2) comprises: pumping the alkali metal hydrosulfide solution and the epoxide solution into a micro-channel mixer, and reacting at 40-120 ℃ to obtain the catalyst.

In a preferred embodiment, the preparation method of the compound represented by the formula (2) comprises: pumping the alkali metal hydrosulfide solution and the epoxide solution into a microchannel mixer, wherein the flow rates of the alkali metal hydrosulfide solution and the epoxide pumped into the microchannel mixer are respectively and independently 1-6mL/min, flowing into a stainless steel coil (the pipe diameter is 3mm, the pipe length is 5 m) through the microchannel mixer, and immersing the coil into heat-conducting oil at the temperature of 50 ℃ to obtain the catalyst.

In a more preferred embodiment, the method for preparing the compound represented by the formula (2) comprises: pumping the alkali metal hydrosulfide solution and the epoxide solution into a microchannel mixer, wherein the flow rates of the alkali metal hydrosulfide solution and the epoxide pumped into the microchannel mixer are respectively and independently 2mL/min, flowing into a stainless steel coil (with the pipe diameter of 3mm and the pipe length of 5 m) through the microchannel mixer, and immersing the coil into heat-conducting oil at the temperature of 50 ℃ to obtain the catalyst.

In one embodiment, the method for preparing the disulfide bond-containing diol comprises the following steps:

(1) pumping the alkali metal hydrosulfide solution and the epoxide solution into a microchannel mixer, wherein the flow rates of the alkali metal hydrosulfide solution and the epoxide pumped into the microchannel mixer are respectively and independently 2mL/min, flowing into a stainless steel coil (the pipe diameter is 3mm, the pipe length is 5 m) through the microchannel mixer, and immersing the coil into heat-conducting oil at the temperature of 50 ℃ to obtain the compound shown in the formula (2);

(2) the compound represented by the formula (2) is flowed out through a coil and then introduced into N₂And (3) adding peroxide into the protected three-neck flask, reacting for 2 hours at 50-60 ℃ to obtain a reaction liquid, adjusting the reaction liquid to be neutral, removing the solvent, and distilling to obtain the product.

The third aspect of the invention provides an application of the diol containing the disulfide bond in preparation of polyester, polyurethane and surfactant.

The preparation process of the polyester, polyurethane and surfactant according to the present invention is not particularly limited and those skilled in the art may make routine selections.

Examples

Hereinafter, the present invention will be described in more detail by way of examples, but it should be understood that these examples are merely illustrative and not restrictive. The starting materials used in the examples which follow are all commercially available unless otherwise stated.

Example 1

Example 1 of the present invention provides one such disulfide bond-containing diol which is 2,2' -dithiodiethanol.

The preparation raw materials of the 2,2' -dithiodiethanol comprise an alkali metal hydrosulfide solution, an epoxide solution and peroxide; the epoxide is ethylene oxide; the alkali metal hydrosulfide is sodium hydrosulfide.

The solvent of the alkali metal hydrosulfide solution is organic solvent and water, and the weight ratio of the organic solvent to the water is 5: 1, the organic solvent is acetone.

The solvent for the epoxide solution is acetone.

The peroxide is hydrogen peroxide.

The preparation method of the 2,2' -dithiodiethanol comprises the following steps: (1) pumping an alkali metal hydrosulfide solution with the concentration of 0.2g/mL and an epoxide solution with the concentration of 0.12g/mL into a microchannel mixer by using two feed pumps respectively, wherein the flow rates of the alkali metal hydrosulfide solution and the epoxide pumped into the microchannel mixer are both 2mL/min, flowing into a stainless steel coil (the pipe diameter is 3mm, the pipe length is 5 m) through the microchannel mixer, and immersing the coil into heat-conducting oil with the temperature of 50 ℃ to obtain an intermediate;

(2) the intermediate flows out through the coil and enters N₂In the protected three-neck flask, when effluent liquid after flowing out reaches 500mL, 76g of peroxide is added into the three-neck flask, reaction is carried out for 2h at 50 ℃ to obtain reaction liquid, the reaction liquid is adjusted to be neutral, the solvent is removed, and distillation is carried out to obtain 33g of 2,2' -dithiodiethanol.

The intermediate is

Example 2

Example 2 of the present invention provides one such disulfide bond-containing diol, which is 2,2' -dithiodipropanol.

The preparation raw materials of the 2,2' -dithiodipropanol comprise alkali metal hydrosulfide solution, epoxide solution and peroxide; the epoxide is propylene oxide; the alkali metal hydrosulfide is sodium hydrosulfide.

The solvent of the alkali metal hydrosulfide solution is organic solvent and water, and the weight ratio of the organic solvent to the water is 10: 1, wherein the organic solvent is DMF.

The solvent for the epoxide solution is acetone.

The peroxide is tert-butyl peroxide.

The preparation method of the 2,2' -dithiodiethanol comprises the following steps: (1) pumping an alkali metal hydrosulfide solution with the concentration of 0.2g/mL and an epoxide solution with the concentration of 0.17g/mL into a microchannel mixer by using two feed pumps respectively, wherein the flow rates of the alkali metal hydrosulfide solution and the epoxide pumped into the microchannel mixer are both 2mL/min, flowing into a stainless steel coil (the pipe diameter is 3mm, the pipe length is 5 m) through the microchannel mixer, and immersing the coil into heat-conducting oil with the temperature of 60 ℃ to obtain an intermediate;

(2) the intermediate flows out through the coil and enters N₂In the protected three-neck flask, when effluent liquid after flowing out reaches 500mL, 64g of peroxide is added into the three-neck flask, reaction is carried out for 2h at 50 ℃ to obtain reaction liquid, the reaction liquid is adjusted to be neutral, the solvent is removed, and distillation is carried out to obtain 38g of 2,2' -dithiodipropanol.

The intermediate is

Example 3

Example 3 of the present invention provides one such disulfide bond-containing diol which is 2,2' -dithiodiethanol.

The preparation raw materials of the 2,2' -dithiodiethanol comprise an alkali metal hydrosulfide solution, an epoxide solution and peroxide; the epoxide is ethylene oxide; the alkali metal hydrosulfide is sodium hydrosulfide.

The solvent of the alkali metal hydrosulfide solution is organic solvent and water, and the weight ratio of the organic solvent to the water is 5: 1, the organic solvent is acetone.

The solvent for the epoxide solution is acetone.

The peroxide is hydrogen peroxide.

The preparation method of the 2,2' -dithiodiethanol comprises the following steps: (1) pumping an alkali metal hydrosulfide solution with the concentration of 0.2g/mL and an epoxide solution with the concentration of 0.4g/mL into a microchannel mixer by using two feed pumps respectively, wherein the flow rates of the alkali metal hydrosulfide solution and the epoxide pumped into the microchannel mixer are both 2mL/min, flowing into a stainless steel coil (the pipe diameter is 3mm, the pipe length is 5 m) through the microchannel mixer, and immersing the coil into heat-conducting oil with the temperature of 50 ℃ to obtain an intermediate;

(2) the intermediate flows out through the coil and enters N₂And (3) in the protected three-neck flask, when effluent liquid after flowing out reaches 500mL, adding 80g of peroxide into the three-neck flask, reacting for 2 hours at 50 ℃ to obtain reaction liquid, adjusting the reaction liquid to be neutral, removing the solvent, and distilling to obtain the catalyst.

The intermediate is

Example 4

Example 4 of the present invention provides one such disulfide bond-containing diol which is 2,2' -dithiodiethanol.

The preparation raw materials of the 2,2' -dithiodiethanol comprise an alkali metal hydrosulfide solution, an epoxide solution and peroxide; the epoxide is ethylene oxide; the alkali metal hydrosulfide is sodium hydrosulfide.

The solvent of the alkali metal hydrosulfide solution is organic solvent and water, and the weight ratio of the organic solvent to the water is 3: 1, the organic solvent is acetone.

The solvent for the epoxide solution is acetone.

The peroxide is hydrogen peroxide.

The preparation method of the 2,2' -dithiodiethanol comprises the following steps: (1) pumping an alkali metal hydrosulfide solution with the concentration of 0.2g/mL and an epoxide solution with the concentration of 0.12g/mL into a microchannel mixer by using two feed pumps respectively, wherein the flow rates of the alkali metal hydrosulfide solution and the epoxide pumped into the microchannel mixer are both 2mL/min, flowing into a stainless steel coil (the pipe diameter is 3mm, the pipe length is 5 m) through the microchannel mixer, and immersing the coil into heat-conducting oil with the temperature of 50 ℃ to obtain an intermediate;

(2) the intermediate flows out through the coil and enters N₂And (3) adding 74g of peroxide into the protected three-neck flask when the effluent liquid reaches 500mL, reacting at 50 ℃ for 2h to obtain a reaction liquid, adjusting the reaction liquid to be neutral, removing the solvent, and distilling to obtain the catalyst.

The intermediate is

Example 5

Example 5 of the present invention provides one such disulfide bond-containing diol which is 2,2' -dithiodiethanol.

The preparation raw materials of the 2,2' -dithiodiethanol comprise an alkali metal hydrosulfide solution, an epoxide solution and peroxide; the epoxide is ethylene oxide; the alkali metal hydrosulfide is sodium hydrosulfide.

The solvent of the alkali metal hydrosulfide solution is organic solvent and water, and the weight ratio of the organic solvent to the water is 5: 1, the organic solvent is acetone.

The solvent for the epoxide solution is acetone.

The peroxide is hydrogen peroxide.

The preparation method of the 2,2' -dithiodiethanol comprises the following steps: (1) pumping an alkali metal hydrosulfide solution with the concentration of 0.38g/mL and an epoxide solution with the concentration of 0.12g/mL into a microchannel mixer by using two feed pumps respectively, wherein the flow rates of the alkali metal hydrosulfide solution and the epoxide pumped into the microchannel mixer are both 2mL/min, flowing into a stainless steel coil (the pipe diameter is 3mm, the pipe length is 5 m) through the microchannel mixer, and immersing the coil into heat-conducting oil with the temperature of 50 ℃ to obtain an intermediate;

(2) the intermediate flows out through the coil and enters N₂In the protected three-neck flask, when effluent liquid after flowing out reaches 500mL, 84g of peroxide is added into the three-neck flask, the mixture reacts for 2 hours at 50 ℃ to obtain reaction liquid, the reaction liquid is adjusted to be neutral, the solvent is removed, and the reaction liquid is steamedDistilling to obtain the product.

The intermediate is

Example 6

Example 6 of the present invention provides one such disulfide bond-containing diol which is 2,2' -dithiodiethanol.

The preparation raw materials of the 2,2' -dithiodiethanol comprise an alkali metal hydrosulfide solution, an epoxide solution and peroxide; the epoxide is ethylene oxide; the alkali metal hydrosulfide is sodium hydrosulfide.

The solvent of the alkali metal hydrosulfide solution is organic solvent and water, and the weight ratio of the organic solvent to the water is 5: 1, the organic solvent is acetone.

The solvent for the epoxide solution is acetone.

The peroxide is hydrogen peroxide.

The preparation method of the 2,2' -dithiodiethanol comprises the following steps: (1) pumping an alkali metal hydrosulfide solution with the concentration of 0.12g/mL and an epoxide solution with the concentration of 0.12g/mL into a microchannel mixer by using two feed pumps respectively, wherein the flow rates of the alkali metal hydrosulfide solution and the epoxide pumped into the microchannel mixer are both 2mL/min, flowing into a stainless steel coil (the pipe diameter is 3mm, the pipe length is 5 m) through the microchannel mixer, and immersing the coil into heat-conducting oil with the temperature of 50 ℃ to obtain an intermediate;

(2) the intermediate flows out through the coil and enters N₂And (3) adding 72g of peroxide into the protected three-neck flask when the effluent liquid after flowing out reaches 500mL, reacting for 2h at 50 ℃ to obtain a reaction liquid, adjusting the reaction liquid to be neutral, removing the solvent, and distilling to obtain the catalyst.

The intermediate is

Example 7

In the dry of N₂Blowing down, installingA batch reactor equipped with a helical stirrer was charged with 72g of dimethyl terephthalate (DMT), 36.7g of 1, 4-Butanediol (BDO), 13.4g of 2,2' -dithiodipropanol obtained in example 2, and 3.6g of tetra-n-butyl titanate. The reactor was heated to 200 ℃ and the transesterification reaction was considered complete when more than 95% of the theoretical amount of methanol had been collected. The reactor temperature was raised to 250 ℃ while the reactor pressure was gradually reduced to 100Pa over 50 min. The polymer was stirred at 245 ℃ and 250 ℃/80Pa to a specific stirrer torque. The polymer melt was extruded to give 87g of a polyester copolymer.

1. Yield: yields of the disulfide bond-containing diols obtained in examples 1 to 6 were calculated, respectively, as the mass of disulfide bond-containing diol/(theoretical mass of epoxide converted into diol in epoxide solution) × 100%.

2. Purity: the purity of the disulfide bond-containing diols obtained in examples 1 to 6 was analyzed by high performance gas chromatography, respectively.

TABLE 1

	Yield (%)	Purity (%)
			Example 1	63	97
Example 2	57	96
			Example 3	60	97
Example 4	59	96
			Example 5	53	95
Example 6	52	95

The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Also, where numerical ranges are used in the claims, subranges therein are included, and variations in these ranges are also to be construed as possible being covered by the appended claims.