阅读说明：本技术 一种高强度间位芳纶聚合体及其制备方法 (High-strength meta-aramid polymer and preparation method thereof ) 是由 任仲恺 宋金苓 张爱华 高东 陈延平 于 2020-10-27 设计创作，主要内容包括：本发明公开了一种高强度间位芳纶聚合体及其制备方法,所述聚合体结构通式如下：式中,连接R1的是具有具有空间结构的金刚烷,所得聚合体粘度为1500-2200Po。本发明涉及的高强度间位芳纶聚合体,是在原有聚间苯二甲酰间苯二胺的基础上,通过引入具有空间结构的新型桥环二胺类化合物,对分子结构进行了优化,提高了聚合体制成纤维后的断裂强度性能,同时保留了间位芳纶原有的优异特性,并使其在工业过滤及高端防护应用领域具有更大的优势,其工艺采用简单易操作的聚合方式,具有极佳的成本优势,易于实现工业化生产。(The invention discloses a high-strength meta-aramid polymer and a preparation method thereof, wherein the polymer has the following structural general formula:)

1. The high-strength meta-aramid polymer is characterized by having the following structural general formula:

wherein n > m, R₁Is an amino compound.

2. A high strength meta-aramid polymer as claimed in claim 1 wherein two of R are present₁Respectively at the 1,3 or 1,4 positions of adamantane.

3. The high strength meta-aramid polymer of claim 1, wherein R is selected from the group consisting of₁is-NH₂、

4. The high strength meta-aramid polymer of claim 1 wherein n is greater than 95% of the total molecular weight of the high strength meta-aramid polymer; the total molecular weight of the high-strength meta-aramid polymer is 25-30 ten thousand.

5. The high strength meta-aramid polymer of claim 1 wherein the viscosity of the high strength meta-aramid polymer is 1500-2200 Po.

6. A preparation method of a high-strength meta-aramid polymer is characterized by comprising the following steps:

s1, adding the raw materials into a solvent, and stirring until the raw materials are completely dissolved to obtain a polar solution; the raw materials are m-phenylenediamine and bridged diamine containing adamantane structure;

s2, controlling the temperature of the polar solution obtained in the step S1 to be 5-25 ℃, and adding isophthaloyl dichloride for the first time to react;

s3, controlling the temperature of the polar solution obtained in the step S2 to be 25-55 ℃, and adding isophthaloyl dichloride for the second time to react;

s4, adding benzoyl chloride into the polar solution obtained in the step S3 for full reaction; the amount of benzoyl chloride added in step S4 is 1% of the total amount of the raw materials in step S1;

s5, neutralizing S4 to obtain a polar solution with the pH value of more than 8.0, and obtaining the high-strength meta-aramid polymer.

7. The method for preparing the high-strength meta-aramid polymer according to claim 6, wherein the bridged diamine containing an adamantane structure has a general structural formula as follows:

wherein R1 is-NH₂、One of (1); two R₁Respectively at the 1,3 or 1,4 positions of adamantane.

8. The method of claim 6, wherein in the step S1, the ratio of the amounts of m-phenylenediamine, bridged diamine containing a adamantane structure, and the polar solvent is: (40-50): 1: (600-750).

9. The method of claim 6, wherein the isophthaloyl dichloride of step S2 is added in an amount of 4/5 based on the total amount of the raw materials of step S1; the amount of isophthaloyl dichloride added in step S3 is 1/5 the amount of the total amount of starting materials in step S1.

Technical Field

The invention belongs to the technical field of aramid polymer, and particularly relates to meta-aramid polymer and a preparation method thereof.

Background

Aromatic polyamide fibers are classified into para-type and meta-type depending on their molecular structures. The para-type product is generally applied as high-strength high-modulus fiber, and the meta-type product is mainly used as a high-temperature resistant fiber material.

The material prepared from the meta-aramid polymer has excellent characteristics, so that the material is developed and applied in various fields. The most mature development at present is the application of the fiber field, and the prepared aramid fiber is known as one of three high-performance fiber materials in the world at present and has the excellent characteristics of high temperature resistance, intrinsic flame retardance, electrical insulation, radiation resistance, chemical corrosion resistance and the like; the material is widely applied to the fields of military police safety protective clothing, high-temperature environment-friendly filter materials, industrial safety protective clothing, high-end electrical appliance insulating materials, secondary stress parts of airplanes and high-speed trains, industrial textiles and the like, and is an important basic material related to the national civilization.

However, the meta-aramid fiber in the current market has generally low strength, and the prepared fabric product generally has poor tear resistance and breaking performance, and cannot meet the requirements of high-end markets.

Disclosure of Invention

The invention aims to provide a high-strength meta-aramid polymer and a preparation method thereof, so as to improve the breaking strength of the meta-aramid polymer and solve the technical problems.

In order to achieve the purpose, the invention adopts the following technical scheme:

a high-strength meta-aramid polymer has the following structural formula:

wherein n > m, R₁Is an amino compound.

The invention further improves the following steps: two R₁Respectively at the 1,3 or 1,4 positions of adamantane.

Further improvements of the inventionThe method comprises the following steps: the R is₁is-NH₂、

The invention further improves the following steps: n accounts for more than 95 percent of the total molecular weight of the high-strength meta-aramid polymer; the total molecular weight of the high-strength meta-aramid polymer is 25-30 ten thousand.

The invention further improves the following steps: the viscosity of the high-strength meta-aramid polymer is 1500-2200 Po.

A preparation method of a high-strength meta-aramid polymer comprises the following steps:

s1, adding the raw materials into a solvent, and stirring until the raw materials are completely dissolved to obtain a polar solution; the raw materials are m-phenylenediamine and bridged diamine containing adamantane structure;

s2, controlling the temperature of the polar solution obtained in the step S1 to be 5-25 ℃, and adding isophthaloyl dichloride for the first time to react;

s3, controlling the temperature of the polar solution obtained in the step S2 to be 25-55 ℃, and adding isophthaloyl dichloride for the second time to react;

s4, adding benzoyl chloride into the polar solution obtained in the step S3 for full reaction; the amount of the benzoyl chloride added in the step S4 is 1% of the total amount of the m-phenylenediamine and the bridged diamine containing a adamantane structure in the step S1;

s5, neutralizing S4 to obtain a polar solution with the pH value of more than 8.0, and obtaining the high-strength meta-aramid polymer.

The invention further improves the following steps: the structural general formula of the bridged ring diamine containing the adamantane structure is as follows:

wherein R1 is-NH₂、One of (1); two R₁Respectively at 1,3 or 1 position of adamantaneAnd 4 bits.

The invention further improves the following steps: in step S1, the ratio of the amounts of m-phenylenediamine, bridged diamine containing a adamantane structure, and polar solvent is: (40-50): 1: (600-750).

The invention further improves the following steps: the addition amount of the isophthaloyl dichloride of the step S2 is 4/5 of the total amount of the raw materials in the step S1; the amount of isophthaloyl dichloride added in step S3 is 1/5 the amount of the total amount of starting materials in step S1.

The invention further improves the following steps: the reaction time in the step S2 is 0.2-8 h; the reaction time in the step S3 is 0.2-8 h; the reaction time in the step S4 is 0.5-1 h.

The invention further improves the following steps: the mass concentration of the polar solution formed in the step S1 is 7% to 9%.

The invention further improves the following steps: after the reaction of the step S4, benzoyl chloride with the amount of 0.05-1% of the material of the raw material is added for end capping, and then the step S5 is carried out.

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

1. the high-strength meta-aramid polymer is prepared by modifying the molecular structure by introducing a novel bridged diamine compound on the basis of the original meta-aramid without changing the characteristics of the meta-aramid and enhancing the intermolecular force, so that the fiber prepared from the modified meta-aramid polymer has excellent spinnability and higher breaking strength in the production process.

2. The high-strength meta-aramid polymer provided by the invention adopts a simple and easy-to-operate polymerization mode, has an excellent cost advantage, and is easy to realize industrial production.

Detailed Description

To further illustrate the present invention, the following are specific examples and should not be construed as limiting the invention. The characteristics in the examples and comparative examples were measured in the following manner.

In the present invention, the polymer viscosity [ Po ]: the dynamic viscosity of the polymer solution is tested by BROOKFIELD DV-II + Pro, a rotor No. 4 is selected, and the result is finally converted into the viscosity at standard temperature (25 ℃) for characterization.

Fiber breaking strength [ cN/dtex ] and elongation at break [% ]: the fibers obtained were tested for breaking strength and elongation at break using the company Australin VP400, VN 400.

The invention relates to a high-strength meta-aramid polymer, which has the following structural general formula:

wherein R1 is-NH₂Or

Preferably, R1 is located at the 1,3 or 1,4 positions of adamantane, respectively.

Preferably, n > m; n accounts for more than 95 percent of the total molecular weight of the high-strength meta-aramid polymer; the total molecular weight of the high-strength meta-aramid polymer is 25 to 30 ten thousand.

The viscosity of the high-strength meta-aramid polymer is 1500-one and 2200 Po.

The method also provides a preparation method of the high-strength meta-aramid polymer, which comprises the following steps:

s1, adding the raw materials into a solvent, and stirring until the raw materials are completely dissolved to obtain a polar solution; the raw materials are m-phenylenediamine and bridged diamine containing adamantane structure; the ratio of the amounts of m-phenylenediamine, bridged diamine containing a adamantane structure and the polar solvent is as follows: (40-50): 1: 600-750;

s2, controlling the temperature of the polar solution obtained in the step S1 to be 5-25 ℃, and adding isophthaloyl dichloride for the first time to react; the addition amount of the isophthaloyl dichloride of the step S2 is 4/5 of the total amount of the raw materials in the step S1;

s3, controlling the temperature of the polar solution obtained in the step S2 to be 25-55 ℃, and adding isophthaloyl dichloride for the second time to react; the addition amount of the isophthaloyl dichloride of the step S3 is 1/5 of the total amount of the raw materials in the step S1;

s4, adding benzoyl chloride into the polar solution obtained in the step S3 for full reaction; the amount of the benzoyl chloride added in the step S4 is 1% of the total amount of the m-phenylenediamine and the bridged diamine containing a adamantane structure in the step S1; in S3, adding a large amount of isophthaloyl dichloride at low temperature to form a large amount of micromolecules; in S3, further heating, increasing the temperature, adding residual isophthaloyl dichloride, and enabling small molecules to be connected in a chain to form large molecules;

s5, neutralizing the polar solution obtained in the step S4 to a pH value of more than 8.0 by adopting calcium hydroxide or other alkaline substances capable of reacting with hydrochloric acid to obtain the high-strength meta-aramid polymer of 1500-2200 Po.

The polar solvent involved in the process of the present invention may be selected from dimethylformamide, dimethylacetamide and N-methylpyrrolidone, which are preferred in the present invention because of their high thermal and hydrolytic stability, and their low corrosiveness and toxicity compared to dimethylformamide.

The addition in the step 1 is more and is not easy to control; low temperature, forming a large amount of small molecules; step 2, raising the temperature to enable the small molecules to be connected in a chain;

the structural general formula of the diammine compound containing the adamantane structure and having the spatial structure related in the method is as follows:

wherein R1 is-NH₂OrR1 is located at the 1,3 or 1,4 positions of adamantane, respectively.

Example 1

Adding 10 parts of m-phenylenediamine and 0.2 part of 1, 3-adamantanediamine by mass into 150 parts of dimethylacetamide, stirring and dissolving to obtain a polar solution, cooling, adding 8.16 parts of isophthaloyl dichloride at 15 ℃, and reacting for 1 hour at the temperature of not more than 25 ℃. Adding 2.04 parts of isophthaloyl dichloride, and controlling the temperature to be 25-55 ℃ to react for 0.5 h. Then, 0.1 part of benzoyl chloride was added thereto, and the mixture was sufficiently stirred for 0.7 hour. After the reaction is finished, calcium hydroxide is added for neutralization, and finally the high-strength meta-aramid polymer with the viscosity of 1800Po (25 ℃) is obtained. The polymer is coagulated and formed by dimethyl acetamide water solution containing calcium chloride, and then after washing, drafting, drying, heat setting, curling, oiling and cutting, the strength of the obtained short fiber can reach more than 5.0cN/dtex, and the elongation at break is more than 40%.

Example 2

Adding 200 parts of N-methylpyrrolidone into 15 parts of m-phenylenediamine and 0.3 part of 1, 3-adamantane diamine according to the parts by weight of the substances, stirring and dissolving to obtain a polar solution, cooling, adding 12.24 parts of isophthaloyl dichloride at 10 ℃, and reacting for 1.5 hours at the temperature of not more than 25 ℃. Adding 3.06 parts of isophthaloyl dichloride, and controlling the temperature to be 25-55 ℃ to react for 0.6 h. 0.15 part of benzoyl chloride was added thereto and stirred well for 0.7 h. After the reaction is finished, calcium hydroxide is added for neutralization, and finally the high-strength meta-aramid polymer with the viscosity of 2182Po (25 ℃) is obtained. The polymer is solidified and formed by N-methyl pyrrolidone aqueous solution containing calcium chloride, and then after washing, drafting, drying, heat setting, curling, oiling and cutting, the strength of the obtained short fiber can reach more than 5.0cN/dtex through testing, and the elongation at break is more than 40%.

Example 3

Adding 20 parts of m-phenylenediamine and 0.4 part of 1, 3-bis (4-aniline) adamantane into 300 parts of dimethylacetamide by weight, stirring and dissolving to obtain a polar solution, cooling, adding 16.32 parts of isophthaloyl dichloride at 15 ℃, and reacting for 1h at the temperature of not more than 25 ℃. Adding 4.08 parts of isophthaloyl dichloride, and controlling the temperature to be 25-55 ℃ to react for 0.5 h. 0.2 part of benzoyl chloride was added and stirred well for 0.7 h. After the reaction is finished, calcium hydroxide is added for neutralization, and finally the high-strength meta-aramid polymer with viscosity of 1650Po (25 ℃) is obtained. The polymer is coagulated and formed by dimethyl acetamide water solution containing calcium chloride, and then after washing, drafting, drying, heat setting, curling, oiling and cutting, the strength of the obtained short fiber can reach more than 5.0cN/dtex, and the elongation at break is more than 40%.

Example 4

Adding 30 parts of m-phenylenediamine and 0.6 part of 1, 3-bis (4-aniline) adamantane into 350 parts of N-methylpyrrolidone by weight, stirring and dissolving to obtain a polar solution, cooling, adding 24.48 parts of isophthaloyl dichloride at 10 ℃, and reacting for 1.5 hours at the temperature of not more than 25 ℃. Adding 6.12 parts of isophthaloyl dichloride, and controlling the temperature to be 25-55 ℃ to react for 0.6 h. 0.3 part of benzoyl chloride was added and stirred well for 0.7 h. After the reaction is finished, calcium hydroxide is added for neutralization, and finally the high-strength meta-aramid polymer with the viscosity of 2116Po (25 ℃) is obtained. The polymer is coagulated and formed by N-methyl pyrrolidone water solution containing calcium chloride, and then after washing, drafting, drying, heat setting, curling, oiling and cutting, the strength of the obtained short fiber can reach more than 5.0cN/dtex through testing, and the elongation at break is more than 40%.

Example 5

Adding 40 parts of m-phenylenediamine and 1 part of 1, 3-adamantanediamine by mass into 600 parts of dimethylacetamide, stirring and dissolving to obtain a polar solution, cooling, adding 32.8 parts of isophthaloyl dichloride at 20 ℃, and reacting for 1 hour at the temperature of not more than 25 ℃. Adding 8.2 parts of isophthaloyl dichloride, and controlling the temperature to be 25-55 ℃ to react for 0.5 h. Then, 0.4 part of benzoyl chloride was added thereto, and the mixture was sufficiently stirred for 1 hour. After the reaction is completed, sodium hydroxide is added for neutralization, and finally the high-strength meta-aramid polymer with the viscosity of 2015Po (25 ℃) is obtained. The polymer is coagulated and formed by dimethyl acetamide water solution containing calcium chloride, and then after washing, drafting, drying, heat setting, curling, oiling and cutting, the strength of the obtained short fiber can reach more than 5.0cN/dtex, and the elongation at break is more than 40%.

The polymer prepared by the invention is solidified and formed by N-methyl pyrrolidone aqueous solution containing calcium chloride, and then is washed, drafted, dried, heat-set, curled, oiled and cut to obtain short fibers; sampling for detection, wherein the sample length is as follows: 51 mm; gauge length: 20 mm; testing speed: 20 mm/min; tension force: 150 mg; the performance parameters are shown in table 1:

TABLE 1 short-staple performance test table

It will be appreciated by those skilled in the art that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed above are therefore to be considered in all respects as illustrative and not restrictive. All changes which come within the scope of or equivalence to the invention are intended to be embraced therein.