Nylon 511 salt and preparation method thereof

Abstract

The invention belongs to the technical field of material synthesis, and discloses a nylon 511 salt and a preparation method thereof. The preparation method of the nylon 511 salt comprises the following steps: mixing undecanedioic acid with absolute ethyl alcohol to obtain an undecanedioic acid ethanol solution; and adding pentamethylene diamine and a seed crystal into the obtained undecanedioic acid ethanol solution, and then carrying out a reaction to obtain the nylon 511 salt. According to the present invention, the nylon 511 salt is prepared under the room temperature condition, the process reaction condition is mild, the inert gas protection is not required, and the pH value in the reaction process does not need to be controlled, such that the whole salt forming process is simple, convenient and easy to control, and the energy consumption is low; the prepared nylon 511 salt has the characteristics of high purity and high yield, and an efficient and feasible process route is provided for industrial production of nylon products.

Description

Technical Field

[0001] The invention relates to the technical field of material synthesis, and in particular to a nylon 511 salt and a preparation method thereof. Background Art

[0002] The synthesis of high-quality monomers is a key step in the preparation of high-quality nylon 511. The preparation of high-purity nylon salts from pentamethylenediamine and undecanediol acid and their direct use in the polymerization of nylon 511 can effectively solve the problems of transportation and portability in the preparation of nylon 511 and improve the quality of the product. However, at the current technical level, the preparation of nylon 511 salts has many problems, such as high salt-forming temperature, yellowing color, and high energy consumption. In addition, in the prior art, most salt-forming processes require the use of a pH meter to monitor and control the pH. These problems have seriously restricted the quality improvement and industrial application of nylon products.

[0003] Therefore, it is very important to study a new and efficient method for preparing high-quality nylon 511 salt in order to achieve efficient production and wide application of nylon products. Summary of the invention

[0004] In view of this, the present invention provides a nylon 511 salt and a preparation method thereof, the purpose of which is to solve the problems of high salt-forming temperature, yellowing color and high energy consumption in the prior art.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing nylon 511 salt, comprising the following steps:

[0007] (1) mixing undecanedioic acid with anhydrous ethanol to obtain an undecanedioic acid ethanol solution;

[0008] (2) Pentamethylenediamine and seed crystals are added to the obtained undecanedioic acid ethanol solution, followed by reaction to obtain nylon 511 salt.

[0009] Preferably, in step (1), the ratio of undecanedioic acid to anhydrous ethanol is 1 g: 5-15 mL.

[0010] Preferably, in step (1), the mixing temperature is 20 to 30°C.

[0011] Preferably, in step (2), the molar ratio of undecanedioic acid to pentamethylenediamine is 1:1 to 1.1.

[0012] Preferably, in step (2), the seed crystals are nylon 511 salt seed crystals, and the mass ratio of undecanediolacid to seed crystals is 0.8-1.2:0.001.

[0013] Preferably, in the step (2), pentamethylenediamine is added to the undecanedioic acid ethanol solution in a dropwise manner at a rate of 0.07 to 0.2 g / min.

[0014] Preferably, in step (2), the reaction temperature is 20 to 40° C., and the reaction time is 0.5 to 4 h.

[0015] Preferably, in step (2), the reaction is carried out under stirring at a rate of 200 to 600 rpm.

[0016] The present invention also provides nylon 511 salt prepared by the preparation method of nylon 511 salt.

[0017] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention realizes the preparation of nylon 511 salt under room temperature conditions, the reaction conditions are mild, no inert gas protection is required, and there is no need to control the pH value of the reaction process. The process route is short, so that the entire salt-forming process is simpler and easier to control, and the energy consumption is low.

[0019] The nylon 511 salt prepared by the present invention has high purity and high yield (the yield can reach 94%, and the product 1 The H-NMR spectrum shows no obvious impurity peaks, indicating that the obtained nylon salt has a high purity), which provides an efficient and feasible process route for the industrial production of nylon products. DETAILED DESCRIPTION

[0020] The present invention provides a method for preparing nylon 511 salt, comprising the following steps:

[0021] (1) mixing undecanedioic acid with anhydrous ethanol to obtain an undecanedioic acid ethanol solution;

[0022] (2) Pentamethylenediamine and seed crystals are added to the obtained undecanedioic acid ethanol solution, followed by reaction to obtain nylon 511 salt.

[0023] In the present invention, in the step (1), the usage ratio of undecanedioic acid to anhydrous ethanol is preferably 1 g: 5 to 15 mL, more preferably 1 g: 8 to 12 mL, and even more preferably 1 g: 10 to 11 mL.

[0024] In the present invention, in the step (1), the mixing temperature is preferably 20-30°C, more preferably 22-28°C, more preferably 24-26°C, and the mixing stirring rate is preferably 200-400 rpm, more preferably 250-350 rpm, more preferably 300-320 rpm.

[0025] In the present invention, in the step (2), the molar ratio of undecanedioic acid to pentamethylenediamine is preferably 1:1-1.1, more preferably 1:1.02-1.08, and more preferably 1:1.04-1.06.

[0026] In the present invention, in the step (2), the seed crystals are preferably nylon 511 salt seed crystals, and the mass ratio of undecane dioic acid to the seed crystals is preferably 0.8-1.2:0.001, more preferably 0.9-1.1:0.001, and more preferably 1:0.001.

[0027] In the present invention, in the step (2), pentamethylenediamine is added dropwise to the undecanedioic acid ethanol solution, and the dropping rate is preferably 0.07 to 0.2 g / min, more preferably 0.1 to 0.18 g / min, and more preferably 0.14 to 0.16 g / min.

[0028] In the present invention, in the step (2), the reaction temperature is preferably 20 to 40°C, more preferably 25 to 35°C, more preferably 30 to 32°C, and the reaction time is preferably 0.5 to 4h, more preferably 1 to 3.5h, more preferably 1.5 to 2h.

[0029] In the present invention, in the step (2), the reaction is carried out under stirring, and the stirring rate is preferably 200 to 600 rpm, more preferably 250 to 550 rpm, and more preferably 300 to 450 rpm.

[0030] In the present invention, in the step (2), after the reaction is completed, solid-liquid separation, washing and drying are preferably performed; the solid-liquid separation is preferably suction filtration; the washing reagent is preferably anhydrous ethanol; the drying is preferably vacuum drying, the vacuum drying temperature is preferably 50 to 80°C, more preferably 55 to 70°C, more preferably 60 to 65°C, and the drying time is preferably 5 to 25h, more preferably 10 to 20h, more preferably 15 to 18h.

[0031] The present invention also provides nylon 511 salt prepared by the preparation method of nylon 511 salt.

[0032] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0033] Example 1

[0034] Weigh 4 g of undecanedioic acid and dissolve it in 30 mL of anhydrous ethanol, and stir it thoroughly at 250 rpm at 25° C. to obtain an undecanedioic acid ethanol solution;

[0035] 1.9 g of pentamethylenediamine was added dropwise to the undecanedioic acid ethanol solution at a rate of 0.1 g / min, and 0.004 g of nylon 511 salt seed was added during the dropping process. After the pentamethylenediamine was added dropwise, the reaction was continued to stir at 400 rpm at 35°C for 2 hours, and then filtered and the obtained solid was washed with anhydrous ethanol. The obtained nylon salt solid was placed in a vacuum oven at 60°C and dried for 12 hours to obtain nylon 511 salt.

[0036] Calculation shows that the yield of nylon 511 salt obtained in this example is 94%.

[0037] Example 2

[0038] Weigh 4 g of undecanedioic acid and dissolve it in 40 mL of anhydrous ethanol, and stir it thoroughly at 300 rpm at 28° C. to obtain an undecanedioic acid ethanol solution;

[0039] 1.9 g of pentamethylenediamine was added dropwise to the undecanedioic acid ethanol solution at a rate of 0.12 g / min, and 0.004 g of nylon 511 salt seed was added during the dropping process. After the pentamethylenediamine was added dropwise, the reaction was continued to stir at 400 rpm at 40°C for 1 hour, and then filtered and the obtained solid was washed with anhydrous ethanol. The obtained nylon salt solid was placed in a vacuum oven at 60°C and dried for 10 hours to obtain nylon 511 salt.

[0040] Calculation shows that the yield of nylon 511 salt obtained in this example is 88%.

[0041] Example 3

[0042] Weigh 4 g of undecanedioic acid and dissolve it in 30 mL of anhydrous ethanol, and stir it thoroughly at 400 rpm at 25° C. to obtain an undecanedioic acid ethanol solution;

[0043] 2 g of pentamethylenediamine was added dropwise to the undecanedioic acid ethanol solution at a rate of 0.14 g / min, and 0.004 g of nylon 511 salt seed was added during the dropping process. After the pentamethylenediamine was added dropwise, the reaction was continued to stir at a rate of 300 rpm at 28°C for 3 hours, and then filtered and the obtained solid was washed with anhydrous ethanol. The obtained nylon salt solid was placed in a vacuum oven at 70°C and dried for 8 hours to obtain nylon 511 salt.

[0044] Calculation shows that the yield of nylon 511 salt obtained in this example is 90%.

[0045] Example 4

[0046] Weigh 4 g of undecanedioic acid and dissolve it in 35 mL of anhydrous ethanol, and stir it thoroughly at 350 rpm at 25° C. to obtain an undecanedioic acid ethanol solution;

[0047] 2 g of pentamethylenediamine was added dropwise to the undecanedioic acid ethanol solution at a rate of 0.1 g / min, and 0.004 g of nylon 511 salt seed was added during the dropping process. After the pentamethylenediamine was added dropwise, the reaction was continued to stir at 200 rpm at 30°C for 3 hours, and then filtered and the obtained solid was washed with anhydrous ethanol. The obtained nylon salt solid was placed in a vacuum oven at 70°C and dried for 10 hours to obtain nylon 511 salt.

[0048] Calculation shows that the yield of nylon 511 salt obtained in this example is 90%.

[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing nylon 511 salt, characterized in that: The steps include: (1) mixing undecanedioic acid with anhydrous ethanol to obtain an undecanedioic acid ethanol solution; (2) Pentamethylenediamine and seed crystals are added to the obtained undecanedioic acid ethanol solution, followed by reaction to obtain nylon 511 salt.

2. The method for preparing nylon 511 salt according to claim 1, characterized in that: In the step (1), the ratio of undecanedioic acid to anhydrous ethanol is 1 g: 5 to 15 mL.

3. The method for preparing nylon 511 salt according to claim 2, characterized in that: In the step (1), the mixing temperature is 20 to 30°C.

4. The method for preparing nylon 511 salt according to claim 3, characterized in that: In the step (2), the molar ratio of undecanedioic acid to pentamethylenediamine is 1:1 to 1.

1.

5. The method for preparing nylon 511 salt according to claim 2 or 4, characterized in that: In the step (2), the seed crystal is a nylon 511 salt seed crystal, and the mass ratio of undecanediolacid to the seed crystal is 0.8-1.2:0.

001.

6. The method for preparing nylon 511 salt according to claim 5, characterized in that: In the step (2), pentamethylenediamine is added to the undecanedioic acid ethanol solution in a dropwise manner at a rate of 0.07 to 0.2 g / min.

7. The method for preparing nylon 511 salt according to claim 6, characterized in that: In the step (2), the reaction temperature is 20 to 40° C., and the reaction time is 0.5 to 4 hours.

8. The method for preparing nylon 511 salt according to claim 7, characterized in that: In the step (2), the reaction is carried out under stirring at a rate of 200 to 600 rpm.

9. Nylon 511 salt obtained by the method for preparing nylon 511 salt according to any one of claims 1 to 8.