阅读说明：本技术 一种梯形低聚物的合成方法 (Synthesis method of trapezoidal oligomer ) 是由 王果 杜柑宏 郭松 于 2020-12-18 设计创作，主要内容包括：本发明公开了一种梯形低聚物的合成方法,其特征在于包括有以下步骤：将亲双烯体和双环戊二烯经过除水除氧处理,随后将亲双烯体与双环戊二烯加入到高压反应釜中,然后加入路易斯酸和溶剂,经连续狄尔斯-阿德耳反应生成所需的梯形低聚物。本发明还公开了应用上述合成方法制得的梯形低聚物。与现有技术相比,本发明的合成方法能够制得结构规整的梯形低聚物。(The invention discloses a synthesis method of a trapezoidal oligomer, which is characterized by comprising the following steps: the dienophile and the dicyclopentadiene are subjected to water removal and oxygen removal treatment, then the dienophile and the dicyclopentadiene are added into a high-pressure reaction kettle, then Lewis acid and solvent are added, and the required ladder-shaped oligomer is generated through continuous Diels-Alder reaction. The invention also discloses a trapezoidal oligomer prepared by applying the synthesis method. Compared with the prior art, the synthesis method can prepare the trapezoidal oligomer with a regular structure.)

1. A method for synthesizing a ladder-shaped oligomer is characterized by comprising the following steps: the dienophile and the dicyclopentadiene are subjected to water removal and oxygen removal treatment, then the dienophile and the dicyclopentadiene are added into a high-pressure reaction kettle, then Lewis acid and solvent are added, and the required ladder-shaped oligomer is generated through continuous Diels-Alder reaction.

2. The method of synthesis according to claim 1, characterized in that: the ladder oligomer has the general formula:

wherein n is any integer of 0-20, R₁、R₂Is hydrogen atom, alkyl or aryl with 1-20 carbon atoms, and X is one of carbon atom or nitrogen atom.

3. The method of synthesis according to claim 2, characterized in that: the dienophile has the general formula:

wherein R is₁、R₂Is hydrogen atom, alkyl group with 1-20 carbon atoms or aryl group, and X is carbon atom or nitrogen atom.

4. The method of synthesis according to claim 3, characterized in that: the dienophile is at least one of the following compounds:

5. the method of synthesis according to claim 1, characterized in that: the Lewis acid catalyst is at least one of zinc chloride, aluminum chloride, ferric chloride, titanium tetrachloride, zinc oxide, aluminum oxide, ferric oxide, titanium oxide, kaolin, zeolite, methyl trifluoromethanesulfonate, boron trifluoride and complexes thereof.

6. The method of synthesis according to claim 1, characterized in that: the solvent is at least one of n-hexane, n-heptane, cyclopentane, cyclohexane, toluene, xylene and cyclopentadiene.

7. The method of synthesis according to claim 1, characterized in that: the mol ratio of the dienophile to the dicyclopentadiene is 1: 2-1: 20.

8. The method of synthesis according to claim 1, characterized in that: the dosage of the Lewis acid catalyst is 0.01-5% of the total weight of the dienophile and the dicyclopentadiene.

9. The synthesis method according to any one of claims 1 to 8, characterized in that: the reaction temperature of the Diels-Alder reaction is 170-250 ℃.

10. A ladder oligomer made using the synthesis method of any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of polymer synthesis, in particular to a synthesis method of a trapezoidal oligomer.

Background

Ladder polymers are a class of linear polymers having a double-stranded structure. Compared with the conventional single-chain linear polymer, the polymer has stronger main chain rigidity, higher thermal stability and high chemical stability. Compared with polymers with a cross-linked structure, the polymer has the characteristic of processability, so that the polymer is widely concerned.

The common ladder-shaped polymer synthesis methods mainly comprise a step-by-step polymerization method and a post-ring closing method. The post-ring closure method is to form a single-chain macromolecule through polymerization, and then carry out intramolecular ring closure reaction to form a ladder-shaped structure. However, this method is not efficient in ring closure reaction, so that the main chain structure of the resulting ladder-shaped polymer has more defects. The formation of these defective structures can be effectively avoided by adopting a stepwise polymerization method.

Cyclopentadiene is an important chemical raw material, and can react with dienophile to prepare an olefin compound with the following structure:

wherein R is₁、R₂、R₃、R₄Is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms or an aryl group, and m is 0 to 1;

the olefin compound can continue to react with cyclopentadiene to form regular ladder-shaped oligomer. Patent publication No. CN1694913A, CN101319020A reports that a cyclic olefin copolymer is obtained by ring-opening copolymerization of such a trapezoidal oligomer with double bonds at the terminal as a raw material, and these polymers have excellent optical properties, high thermal stability and high mechanical strength, are widely used in the fields of optical materials, polarizing plates, liquid crystal displays and the like, and have important application values; patent publication No. CN107011610A discloses a polyolefin film prepared from such oligomer as a raw material, which can be used as a substrate of a touch panel and effectively improve the adhesion with a transparent conductive layer.

However, reports on how to synthesize the ladder-shaped oligomer are still few, and related researches are also poor. This is because, when cyclopentadiene is used as a reaction raw material, cyclopentadiene can be used as both a diene and a dienophile in a diels-alder reaction, and thus cyclopentadiene is liable to undergo reactions such as dimerization and trimerization itself, and the resulting product contains at least two or more double bonds, such as DCPD and TCPD, and thus the above-mentioned ladder-shaped oligomer having a regular structure cannot be obtained.

Disclosure of Invention

The first technical problem to be solved by the present invention is to provide a synthetic method of a ladder-shaped oligomer, which can prepare a ladder-shaped oligomer with a regular structure, aiming at the current situation of the prior art.

The second technical problem to be solved by the invention is to provide a ladder-shaped oligomer prepared by applying the synthesis method.

The technical scheme adopted by the invention for solving the first technical problem is as follows: a method for synthesizing a ladder-shaped oligomer is characterized by comprising the following steps: the dienophile and the dicyclopentadiene are subjected to water removal and oxygen removal treatment, then the dienophile and the dicyclopentadiene are added into a high-pressure reaction kettle, then Lewis acid and solvent are added, and the required ladder-shaped oligomer is generated through continuous Diels-Alder reaction.

Preferably, the ladder oligomer has the formula:

wherein n is any integer of 0-20, R₁、R₂Is hydrogen atom, alkyl or aryl with 1-20 carbon atoms, and X is one of carbon atom or nitrogen atom.

Further, the dienophile has the general formula:

wherein R is₁、R₂Is hydrogen atom, alkyl group with 1-20 carbon atoms or aryl group, and X is carbon atom or nitrogen atom.

Still further, the dienophile is at least one of the following compounds:

preferably, the lewis acid catalyst is at least one of zinc chloride, aluminum chloride, ferric chloride, titanium tetrachloride, zinc oxide, aluminum oxide, ferric oxide, titanium oxide, kaolin, zeolite, methyl triflate, boron trifluoride, and complexes thereof; further, the Lewis acid catalyst is titanium tetrachloride.

Preferably, the solvent is at least one of n-hexane, n-heptane, cyclopentane, cyclohexane, toluene, xylene and cyclopentadiene; further, the solvent is cyclopentane.

Preferably, the mol ratio of the dienophile to the dicyclopentadiene is 1: 2-1: 20; further, the mol ratio of the dienophile to the dicyclopentadiene is 1: 5-1: 10. The length and molecular weight of oligomer chain links can be adjusted by adjusting the feeding proportion between the dienophile and the dicyclopentadiene in the raw materials.

Preferably, the dosage of the Lewis acid catalyst is 0.01-5% of the total weight of the dienophile and the dicyclopentadiene; further, the dosage of the Lewis acid catalyst is 1-3% of the total weight of the dienophile and the dicyclopentadiene.

Preferably, the reaction temperature of the Diels-Alder reaction is 170-250 ℃; further, the reaction temperature is 190-220 ℃.

The technical scheme adopted by the invention for solving the second technical problem is as follows: a ladder-shaped oligomer prepared by the synthesis method.

Compared with the prior art, the invention has the advantages that: under the action of Lewis acid catalyst, the depolymerization reaction of dicyclopentadiene is promoted to produce cyclopentadiene, and then the Lewis acid catalyst interacts with the produced cyclopentadiene, so that cyclopentadiene can only be used as diene to participate in Diels-Alder reaction and reacts with double bonds at the tail end of added dienophile or oligomer chain to gradually polymerize and finally form ladder-shaped oligomer with regular structure.

Detailed Description

The present invention will be described in further detail with reference to examples.

Example 1:

purifying ethylene and dicyclopentadiene by a purifying device to remove water and remove oxygen, wherein the molar ratio of ethylene to dicyclopentadiene is 1: adding 3 parts by mass of titanium tetrachloride and 50 parts by mass of anhydrous n-hexane into a reaction kettle, stirring, heating to the reaction temperature of 190 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding the reacted mixed solution into 500 parts by mass of anhydrous ethanol, immediately precipitating a large amount of white precipitate, filtering to obtain the precipitate, washing with the anhydrous ethanol for multiple times, drying in vacuum at room temperature for 24 hours, and finally weighing to obtain the polymer with the yield of 87.4%.

Example 2:

purifying propylene and dicyclopentadiene by a purifying device to remove water and remove oxygen, wherein the molar ratio of propylene to dicyclopentadiene is 1: adding 10 parts of titanium oxide and 50 parts of anhydrous cyclohexane into a reaction kettle, stirring, heating to the reaction temperature of 170 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding the mixed solution obtained by the reaction into 500 parts of anhydrous ethanol, immediately precipitating a large amount of white precipitate, filtering to obtain the precipitate, washing with the anhydrous ethanol for multiple times, drying in vacuum at room temperature for 24 hours, and finally weighing to obtain the polymer with the yield of 81.9%.

Example 3:

purifying octene and dicyclopentadiene by a purifying device to remove water and remove oxygen, wherein the mol ratio of octene to dicyclopentadiene is 1: 15, adding 0.5 part by mass of aluminum chloride and 50 parts by mass of anhydrous toluene into a reaction kettle, starting stirring, heating to the reaction temperature of 220 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding the mixed solution obtained by the reaction into 500 parts by mass of anhydrous ethanol, immediately precipitating a large amount of white precipitate, filtering to obtain the precipitate, washing with the anhydrous ethanol for multiple times, drying in vacuum for 24 hours at room temperature, and finally weighing to obtain the polymer with the yield of 72.1%.

Example 4:

purifying cyclohexene and dicyclopentadiene by a purifying device to remove water and oxygen, wherein the molar ratio of cyclohexene to dicyclopentadiene is 1: adding 20 parts of alumina and 50 parts of toluene into a reaction kettle, stirring, heating to the reaction temperature of 170 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding the mixed solution obtained by the reaction into 500 parts of absolute ethyl alcohol, immediately precipitating a large amount of white precipitate, filtering to obtain the precipitate, washing with absolute ethyl alcohol for multiple times, and drying in vacuum for 24 hours at room temperature, wherein the yield of the polymer obtained by weighing is 56.3%.

Example 5:

purifying 2-butene and dicyclopentadiene by a purifying device to remove water and oxygen, wherein the molar ratio of 1: adding 5 parts by mass of titanium tetrachloride and 50 parts by mass of cyclopentane into a reaction kettle, stirring, heating to the reaction temperature of 220 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding the mixed solution obtained by the reaction into 500 parts by mass of absolute ethyl alcohol, immediately precipitating a large amount of white precipitate, filtering to obtain the precipitate, washing with absolute ethyl alcohol for multiple times, drying in vacuum for 24 hours at room temperature, and finally weighing to obtain the polymer with the yield of 85.2%.

Example 6:

purifying ethylene and dicyclopentadiene by a purifying device to remove water and remove oxygen, wherein the molar ratio of ethylene to dicyclopentadiene is 1: adding 3 parts by mass of zeolite and 50 parts by mass of cyclopentane into a reaction kettle, stirring, heating to the reaction temperature of 190 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding the mixed solution obtained by the reaction into 500 parts by mass of absolute ethyl alcohol, immediately separating out a large amount of white precipitate, filtering to obtain precipitate, washing with absolute ethyl alcohol for multiple times, and drying in vacuum for 24 hours at room temperature, and finally weighing to obtain the polymer with the yield of 87.4%.

Example 7:

purifying phenyl- (2-phenylethylene) amine and dicyclopentadiene by a purifying device to remove water and oxygen, wherein the molar ratio of the phenyl- (2-phenylethylene) amine to the dicyclopentadiene is 1: adding 5 parts by mass of titanium tetrachloride and 50 parts by mass of xylene into a reaction kettle, stirring, heating to the reaction temperature of 220 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding the mixed solution obtained by the reaction into 500 parts by mass of absolute ethyl alcohol, immediately separating out a light yellow precipitate, filtering to obtain a precipitate, washing with absolute ethyl alcohol for multiple times, drying in vacuum at room temperature for 24 hours, and finally weighing to obtain the polymer with the yield of 68.8%.

Example 8:

purifying cyclohexene and dicyclopentadiene by a purifying device to remove water and oxygen, wherein the molar ratio of cyclohexene to dicyclopentadiene is 1: adding 1 part by mass of titanium tetrachloride and 50 parts by mass of cyclopentane into a reaction kettle, stirring, heating to the reaction temperature of 250 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding the mixed solution obtained by the reaction into 500 parts by mass of absolute ethyl alcohol, immediately precipitating a large amount of white precipitate, filtering to obtain the precipitate, washing with absolute ethyl alcohol for multiple times, drying in vacuum at room temperature for 24 hours, and finally weighing to obtain the polymer with the yield of 79.3%.

Example 9:

purifying octene and dicyclopentadiene by a purifying device to remove water and remove oxygen, wherein the mol ratio of octene to dicyclopentadiene is 1: adding the raw materials into a reaction kettle according to a feeding ratio of 5, adding 0.05 part by mass of boron trifluoride and 50 parts by mass of n-hexane into the reaction kettle, starting stirring, heating to the reaction temperature of 230 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding a mixed solution obtained by the reaction into 500 parts by mass of absolute ethyl alcohol, immediately precipitating a large amount of white precipitate, filtering to obtain the precipitate, washing with the absolute ethyl alcohol for multiple times, drying in vacuum for 24 hours at the room temperature, and finally weighing to obtain the polymer with the yield of 69.3%.

Example 10:

purifying ethylene and dicyclopentadiene by a purifying device to remove water and remove oxygen, wherein the molar ratio of ethylene to dicyclopentadiene is 1: adding a material feeding ratio of 7 into a reaction kettle, adding 0.01 part by mass of titanium tetrachloride and 50 parts by mass of n-hexane into the reaction kettle, starting stirring, heating to the reaction temperature of 200 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding a mixed solution obtained by the reaction into 500 parts by mass of absolute ethyl alcohol, immediately precipitating a large amount of white precipitate, filtering to obtain the precipitate, washing with the absolute ethyl alcohol for multiple times, drying in vacuum for 24 hours at room temperature, and finally weighing to obtain the polymer with the yield of 78.4%.

Comparative example 1:

purifying ethylene and dicyclopentadiene by a purifying device to remove water and remove oxygen, wherein the molar ratio of ethylene to dicyclopentadiene is 1: and 5, adding 50 parts by mass of n-hexane into the reaction kettle, starting stirring, heating to the reaction temperature of 190 ℃, keeping the temperature for reaction for 4 hours, cooling to room temperature, adding the mixed solution obtained by the reaction into 500 parts by mass of absolute ethyl alcohol, and separating out no solid.

The ladder-shaped oligomer obtained above was subjected to nuclear magnetic characterization, and the calculated average polymerization degree was shown in table 1 below.

Table 1:

	catalyst and process for preparing same	Reaction temperature (. degree.C.)	Dienophile/dicyclopentadiene molar ratio	Average degree of polymerization
					Example 1	Titanium tetrachloride	190	1:5	10
Example 2	Titanium oxide	170	1:10	16
					Example 3	Aluminium chloride	220	1:15	21
Example 4	Alumina oxide	170	1:20	23
					Example 5	Titanium tetrachloride	220	1:5	9
Example 6	Zeolite	190	1:2	4
					Example 7	Titanium tetrachloride	220	1:5	8
Example 8	Titanium tetrachloride	250	1:5	8
					Example 9	Boron trifluoride	230	1:5	9
Example 10	Titanium tetrachloride	200	1:7	12

From the above experimental results it can be seen that:

(1) in the embodiment, under the action of a Lewis acid catalyst, the depolymerization reaction of dicyclopentadiene is promoted to generate cyclopentadiene, and then the Lewis acid catalyst interacts with the generated cyclopentadiene, so that cyclopentadiene can only be used as diene to participate in Diels-Alder reaction and reacts with double bonds at the tail end of a chain of added dienophile or oligomer to be gradually polymerized to finally form a trapezoidal oligomer with a regular structure;

in the comparative example, because no catalyst is added, the dicyclopentadiene monomer cannot be subjected to effective polymerization reaction, and only oily small molecular substances can be generated, because cyclopentadiene can be used as both diene and dienophile, under the condition of no catalyst, cyclopentadiene is continuously subjected to dimerization reaction, so that cyclopentadiene cannot participate in the reaction as diene, and finally the degree of polymerization cannot be increased, so that regular trapezoidal oligomers cannot be obtained;

(2) as can be seen from Table 1, by adjusting the feeding ratio between the dienophile and dicyclopentadiene in the raw materials, the chain length and molecular weight of the oligomer can be adjusted, thereby obtaining the ladder-shaped oligomer with different average polymerization degrees.