CN110824087A

CN110824087A - Quantitative detection method for residual azodiisobutyronitrile in solvent

Info

Publication number: CN110824087A
Application number: CN201911113102.3A
Authority: CN
Inventors: 王斐; 赵红霞; 张聪莉
Original assignee: Lanzhou Lan-Star Fiber Co Ltd
Current assignee: Lanzhou Lan-Star Fiber Co Ltd
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2020-02-21

Abstract

The invention relates to a quantitative detection method of azodiisobutyronitrile residual in a solvent, belonging to the field of acrylonitrile polymerization spinning. The quantitative detection method comprises the following steps: firstly, establishing a standard curve of the azobisisobutyronitrile solution, and then measuring the content of the residual azobisisobutyronitrile in the solvent. The method is very sensitive and accurate in detection of the residual azodiisobutyronitrile in the solvent, and is worthy of popularization and application.

Description

Quantitative detection method for residual azodiisobutyronitrile in solvent

Technical Field

The invention relates to the field of acrylonitrile polymerization spinning, and in particular relates to a quantitative detection method for residual azodiisobutyronitrile in a solvent.

Background

In the production process of polyacrylonitrile fibers, the used initiator is mainly azobisisobutyronitrile, the solvent is recycled in production, part of azobisisobutyronitrile remaining in the solvent is recycled while the solvent is recycled, and the amount of the remaining azobisisobutyronitrile must be strictly controlled in production, because the remaining undecomposed azobisisobutyronitrile is always decomposed in the post-treatment process and releases nitrogen, the spinning stability and the protofilament quality are seriously affected, and the production strength of subsequent carbon fibers is affected. Therefore, it is necessary to measure the content of the residual azobisisobutyronitrile in the recovered solvent.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a quantitative detection method for residual azodiisobutyronitrile in a solvent.

One of the purposes of the invention is to provide a quantitative detection method for residual azodiisobutyronitrile in a solvent, which comprises the following steps: firstly, establishing a standard curve of the azobisisobutyronitrile solution, and then measuring the content of the residual azobisisobutyronitrile in the solvent.

The step of establishing a standard curve of the azobisisobutyronitrile solution comprises the following steps:

preparing standard solutions of azobisisobutyronitrile with a series of concentrations, and testing the standard solutions by using a high performance liquid chromatograph. The temperature of the chromatographic column is 25-35 ℃, preferably 30 ℃, and the mobile phase is a mixed solution of acetonitrile and water in a volume ratio of 30: 70-70: 30, preferably 1: 1, the speed of a mobile phase is 0.5-1 mL/min, preferably 0.5mL/min, the detector is an ultraviolet detector, the detection wavelength is 346nm, and the sample injection volume is 5-15 uL, preferably 10 uL; and drawing a standard curve according to the concentration of the azodiisobutyronitrile and the peak area of the azodiisobutyronitrile.

The standard solutions of the azobisisobutyronitrile with the series of concentrations are standard solutions of the azobisisobutyronitrile with the concentration of 2ppm, 10ppm, 50ppm, 100ppm and 200ppm respectively; the solvent of the azodiisobutyronitrile standard solution is dimethyl sulfoxide.

The step of determining the content of the residual azobisisobutyronitrile in the solvent comprises the following steps:

and testing the solvent to be tested by using HPLC, measuring the integral area of the azodiisobutyronitrile peak, and calculating the residual quantity of the azodiisobutyronitrile on a standard curve. Preferably, the solvent to be tested may be pretreated before the test, in particular, the pretreatment may include an extraction separation step of the solvent to be tested:

weighing about 3-8 g of the solvent to be detected into 30-120 mL of dichloromethane, washing the solvent with 30-80 mL of water for multiple times, washing the water phase with 30-80 mL of dichloromethane for 2-4 times, combining organic phases, drying, filtering, performing rotary evaporation to remove dichloromethane, and supplementing acetonitrile (generally 2-5 g) to be the same as the volume of the solvent to be detected for later use. The step can better separate and enrich the substance azodiisobutyronitrile to be detected.

The invention aims to detect the content of the azodiisobutyronitrile remained in the solvent, and has the advantages of accurate detection, sensitivity, high efficiency and simple and convenient operation.

Drawings

FIG. 1 is a standard curve of azobisisobutyronitrile solution.

Detailed Description

The present invention will be further described with reference to the following examples. However, the present invention is not limited to these examples.

The starting materials used in the examples are all commercially available.

Example 1

Equipment Waters ACQUITY UPLCTM High Performance Liquid Chromatograph (HPLC).

The method comprises the following operation steps:

1. establishing a standard curve of the azodiisobutyronitrile solution:

preparing azodiisobutyronitrile standard solutions with the concentrations of 2ppm, 10ppm, 50ppm, 100ppm and 200ppm respectively, wherein the solvent is dimethyl sulfoxide, and testing the standard solutions by using a high performance liquid chromatograph. The column temperature of the chromatographic column was 30 ℃ and the ratio of mobile phase acetonitrile to water was 1: 1, the speed of the mobile phase is 0.5mL/min, the detector is an ultraviolet detector, the detection wavelength is 346nm, and the sample injection volume is 10 uL. The above solution was analyzed by HPLC to obtain the data shown in Table 1. A standard curve was drawn based on the concentration of azobisisobutyronitrile and the measured peak area of azobisisobutyronitrile, as shown in FIG. 1.

2. Determining the content of the residual azodiisobutyronitrile in the solvent:

preparing azodiisobutyronitrile solution, wherein the solvent is dimethyl sulfoxide, the concentration is 47.1ppm, the solution is taken and tested by HPLC, the integral area of the azodiisobutyronitrile peak is 3662, the residual content of the azodiisobutyronitrile is calculated on a standard curve, and the concentration of the azodiisobutyronitrile is 41.71ppm by calculation according to the calculation formula shown in figure 1.

Preparing 20ppm azodiisobutyronitrile solution, taking 4g of the solution, and taking 1g of the prepared solvent without azodiisobutyronitrile to obtain 16ppm solvent-containing azodiisobutyronitrile solution. The solvent was tested by HPLC and the integrated area of the azobisisobutyronitrile peak was 1377. The concentration of azobisisobutyronitrile was 15.23ppm as calculated from the calculation formula of FIG. 1.

From the above test results, it can be seen that the method of the present application is very sensitive and accurate for detecting residual azobisisobutyronitrile in a solvent.

TABLE 1

AIBN concentration/ppm	346nm detection
		2	186
10	850
		50	4569
100	8542
		200	17635

Claims

1. A quantitative detection method for residual azodiisobutyronitrile in a solvent is characterized by comprising the following steps: firstly, establishing a standard curve of the azobisisobutyronitrile solution, and then measuring the content of the residual azobisisobutyronitrile in the solvent.

2. The method according to claim 1, wherein the step of quantitatively detecting the azodiisobutyronitrile remaining in the solvent comprises the steps of:

preparing standard solutions of azobisisobutyronitrile with a series of concentrations, testing by using a high performance liquid chromatograph, and drawing a standard curve according to the concentration of the azobisisobutyronitrile and the peak area of the azodiisobutyronitrile.

3. The method according to claim 2, wherein the step of quantitatively detecting the azodiisobutyronitrile remaining in the solvent comprises the steps of:

the standard solutions of azobisisobutyronitrile with the series of concentrations are standard solutions of azobisisobutyronitrile with the concentration of 2ppm, 10ppm, 50ppm, 100ppm and 200ppm respectively.

4. The method according to claim 2, wherein the step of quantitatively detecting the azodiisobutyronitrile remaining in the solvent comprises the steps of:

in the test, the column temperature of the chromatographic column is 25-35 ℃, and the sample injection volume is 5-15 uL.

5. The method according to claim 2, wherein the step of quantitatively detecting the azodiisobutyronitrile remaining in the solvent comprises the steps of:

in the test, the detector is an ultraviolet detector, and the detection wavelength is 346 nm.

6. The method according to claim 2, wherein the step of quantitatively detecting the azodiisobutyronitrile remaining in the solvent comprises the steps of:

in the test, the mobile phase is a mixed solution of acetonitrile and water in a volume ratio of 30: 70-70: 30, and the speed of the mobile phase is 0.5-1 mL/min.

7. The method according to claim 3, wherein the step of quantitatively detecting the azodiisobutyronitrile remaining in the solvent comprises the steps of: the solvent of the azodiisobutyronitrile standard solution is dimethyl sulfoxide.

8. The method according to claim 1, wherein the step of quantitatively detecting the azodiisobutyronitrile remaining in the solvent comprises the steps of:

and testing the solvent to be tested by using HPLC, measuring the integral area of the azodiisobutyronitrile peak, and calculating the residual quantity of the azodiisobutyronitrile on a standard curve.

9. The method according to claim 8, wherein the step of quantitatively detecting the azodiisobutyronitrile remaining in the solvent comprises the steps of:

the solvent to be tested is pretreated before testing:

the pretreatment comprises the following steps:

weighing 3-8 g of the solvent to be detected, adding the solvent to be detected into 30-120 mL of dichloromethane, washing the solvent for multiple times by using 30-80 mL of water, washing the water phase for 2-4 times by using 30-80 mL of dichloromethane, combining the organic phases, drying, filtering, performing rotary evaporation to remove dichloromethane, and supplementing acetonitrile to be the same as the volume of the solvent to be detected for later use.