Qualitative analysis method of fluorine-containing quaternary ammonium salt ionic liquid

Abstract

The invention discloses a qualitative analysis method of fluorine-containing quaternary ammonium salt ionic liquid, which comprises the following steps: S1, preparation of a sample to be detected: adding the sample to be detected into a nuclear magnetic tube, then adding a deuterated reagent, and fully and uniformly dissolving for later use; s2, parameter point inspection before use of the nuclear magnetic resonance spectrometer: liquid helium is greater than or equal to 40%, liquid nitrogen is greater than or equal to 40%, an automatic sampler is well connected with the NMR, and a standard sample shimming result meets instrument requirements; the temperature of the differential thermal analyzer is 0-600 DEG C; and S3, detecting by using a nuclear magnetic resonance spectrometer and a differential thermal analyzer according to the use requirements of the instrument. The detection method provided by the invention is simple and rapid to operate, high in efficiency and environment-friendly. According to the invention, a criterion is provided for the qualification of the fluorine-containing quaternary ammonium salt ionic liquid, and the qualitative problems of large molecular weight and complex structure of the ionic liquid are solved.

Description

Technical Field

[0001] The invention relates to the technical field of chemical analysis and detection, and in particular to a qualitative analysis method for fluorine-containing quaternary ammonium salt ionic liquids. Background Art

[0002] With the development of the electronic information industry, the touch screen market is developing faster and faster, and the scale of the touch screen industry is further increasing. The technology of the protective film used on the surface of the touch screen is also improving synchronously, among which the main requirement is that the protective film must have excellent antistatic properties. The new antistatic agent tri-n-butyl methyl ammonium bis (trifluoromethylsulfonyl) imide currently used at home and abroad has the following advantages over traditional antistatic agents: 1) good solubility in various polymers - optical transparency; 2) stable high temperature processing - thermal stability; 3) excellent melt processing stability.

[0003] In the preparation method of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide ionic liquid in Chinese patent CN118184553A, the detection of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide mainly includes the detection of water content, chromaticity and metal and other impurity contents. However, there is no report on the thermal stability data and structural analysis detection of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide. Tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide has a complex structure, and it is difficult to perform a qualitative structural analysis on it using conventional analytical means. Summary of the invention

[0004] In order to correctly qualitatively analyze the structure of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide and understand its excellent stability, the present invention provides an accurate and simple qualitative analysis method for fluorine-containing quaternary ammonium salt ionic liquids, which can quickly understand the quality of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide and solve the problem of difficulty in qualitative analysis of its structure.

[0005] The technical solution adopted by the present invention is:

[0006] A qualitative analysis method for fluorine-containing quaternary ammonium salt ionic liquids comprises the following steps:

[0007] S1. Preparation of samples to be tested:

[0008] Add the sample to be tested into the NMR tube, then add the deuterated reagent, fully dissolve and set aside;

[0009] S2. Parameter inspection before using the NMR spectrometer: liquid helium ≥ 40%, liquid nitrogen ≥ 40%, the automatic sampler is connected to the NMR intact, and the standard sample uniform field results meet the instrument requirements;

[0010] The temperature of the differential thermal analyzer is within 0~600℃;

[0011] S3. Use nuclear magnetic resonance spectrometer and differential thermal analyzer to perform testing in accordance with the instrument usage requirements.

[0012] Preferably, the specification of the NMR tube used in S1 is: Φ5mm*20cm, made of glass.

[0013] Preferably, the sample to be tested in S1 is a fluorine-containing quaternary ammonium salt ionic liquid.

[0014] Preferably, the fluorine-containing quaternary ammonium salt ionic liquid is tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide.

[0015] Preferably, the deuterated reagent in S1 is DMSO.

[0016] Preferably, the amount of the sample to be tested in S1 is 5-8 mg, and the amount of the deuterated reagent added is 0.6 mL.

[0017] Preferably, when a differential thermal analyzer is used for thermogravimetric analysis in S2, no sample pretreatment is required, programmed temperature is used, and the atmosphere is N2; the standard sample uniform field result meets the instrument requirement: Fina1 B0<1.

[0018] Preferably, the nuclear magnetic resonance spectrometer in S2 is manufactured by Bruker of Germany, with a model of 400 MHz; the differential thermal analyzer is manufactured by Mettler, with a model of TGA2.

[0019] Preferably, the nuclear magnetic resonance spectrometer detection conditions in S3 are as follows:

[0020] 13 C: DS=2~4, NS=1024, D1=0~2, O1P=+100ppm

[0021] 19 F: DS=2~4, NS=16, D1=0~2, O1P=-100ppm

[0022] 1 H: DS=2~4, NS=16, D1=0~2, O1P=+4.2ppm;

[0023] Analysis time: 15 minutes.

[0024] Preferably, the differential thermal analyzer detection conditions in S3 are as follows:

[0025] The gradient heating rate is constant, and the heating gradient is: 180℃~300℃~430℃~450℃.

[0026] The beneficial effects obtained by the present invention are:

[0027] 1. The method provided by the present invention is simple, rapid and accurate in detecting the structure and thermal stability of fluorine-containing quaternary ammonium salt ionic liquids.

[0028] 2. The detection method provided by the present invention is simple, fast, efficient and environmentally friendly.

[0029] 3. The present invention provides a criterion for the qualitative analysis of fluorine-containing quaternary ammonium salt ionic liquids, and solves the qualitative analysis problem of ionic liquids with large molecular weight and complex structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the nuclear magnetic resonance spectrum of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide according to the embodiment of the present invention ( 13 C);

[0031] Figure 2 This is the nuclear magnetic resonance spectrum of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide according to the embodiment of the present invention ( 19 F);

[0032] Figure 3 This is the nuclear magnetic resonance spectrum of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide according to the embodiment of the present invention ( 1 H);

[0033] Figure 4 This is a differential thermal analysis spectrum of an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0035] Unless otherwise specified, the following instruments, reagents, and raw materials can be purchased through commercial channels. The instruments are from:

[0036] 400 MHz nuclear magnetic resonance spectrometer (Bruker), thermogravimetric analyzer (Mettler);

[0037] In the repeatability test, the following instrument parameters and reagent conditions were used:

[0038] 1) Instrument conditions

[0039] 13 C: DS=2~4, NS=1024, D1=0~2, O1P=+100ppm

[0040] 19 F: DS=2~4, NS=16, D1=0~2, O1P=-100ppm

[0041] 1H: DS=2~4, NS=16, D1=0~2, O1P=+4.2ppm

[0042] 2) Reagent conditions

[0043] condition parameter <![CDATA[CDCl3]]> Bailingwei Technology Co., Ltd. <![CDATA[D2O]]> Bailingwei Technology Co., Ltd. DMSO Bailingwei Technology Co., Ltd. Tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide self made

[0044] Example 1

[0045] A method for characterizing the structure of a fluorine-containing quaternary ammonium salt ionic liquid comprises the following steps:

[0046] S1. Preparation of samples to be tested: accurately weigh about 5.8000 mg of sample (accurate to 4 decimal places), place it in a Φ5 mm NMR tube, and dissolve it in 0.6 mL of deuterated reagent to prepare a sample solution for later use;

[0047] S2. Parameter inspection of nuclear magnetic resonance spectrometer before use: liquid helium ≥ 40%, liquid nitrogen ≥ 40%, the automatic sampler and NMR are connected intact, and the standard sample uniform field result meets the instrument requirements: Fina1 B0 <1.

[0048] S3, NMR detection: Place the sample tube prepared in A into the automatic sampler and perform the detection according to the instrument operation requirements;

[0049] The NMR conditions were: analysis time 15 min.

[0050] Example 2

[0051] A stability analysis method for fluorine-containing quaternary ammonium salt ionic liquids comprises the following steps:

[0052] S1. Preparation of samples to be tested: directly test, the fluorine-containing quaternary ammonium salt ionic liquid is tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide;

[0053] S2. Instrument parameters:

[0054] The temperature was raised by programmed heating and the atmosphere was N2.

[0055] S3. The conditions for the programmed temperature rise in step S2 are: the gradient temperature rise rate is constant, the temperature rise gradient is set, and each set temperature point is maintained for 3-5 minutes. The detection time is not less than 23 minutes.

[0056] Conditional Example

[0057] Exploration of the test conditions of Example 1:

[0058] 1. Structural characterization of fluorine-containing quaternary ammonium salt ionic liquids

[0059] Currently, the qualitative analysis of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide is carried out. Related experiments are carried out on the selection of deuterated reagents, scanning times and other conditions:

[0060] Changes in testing conditions <![CDATA[Number of scans 1 H / 13 C]]> Preparation of sample solution Peak situation None 16 / 1024 Samples are clear and transparent Characteristic peak separation effect is not good <![CDATA[D2O]]> 16 / 1024 The sample is turbid and stratified The characteristic peak (tri-n-butyl peak) cannot be separated <![CDATA[CDCl3]]> 16 / 1024 The sample is turbid and stratified The characteristic peak (tri-n-butyl peak) cannot be separated MDSO 16 / 1024 Samples are clear and transparent Good separation of characteristic peaks MDSO 32 / 1024 Samples are clear and transparent The characteristic peak separation effect is better, and the time becomes longer MDSO 32 / 2048 Samples are clear and transparent The characteristic peak separation effect is better, and the time becomes longer MDSO 64 / 2048 Samples are clear and transparent The characteristic peak separation effect is better, and the time becomes longer

[0061] Based on the above experimental conditions, DMSO was selected as the deuterated reagent, and the scanning times of different spectra were:

[0062] 1 H: NS = 16 (see experimental results Figure 3 ); 19 F: NS = 16 (see experimental results Figure 2 ); 13 C: NS = 1024 (see the experimental results Figure 1 )

[0063] The above conditions were used as the test conditions, and relevant repeatability verification was carried out.

[0064] Exploration of the test conditions of Example 2:

[0065] 2. Thermal stability analysis of fluorine-containing quaternary ammonium salt ionic liquids

[0066] In order to quickly understand the thermal stability of fluorine-containing quaternary ammonium salt ionic liquids, the following experimental exploration was carried out on the conditions of programmed temperature rise:

[0067]

[0068] Based on the above experimental conditions, the gradient conditions were selected: 180℃~300℃~430℃~450℃, constant temperature rise, and each point maintained for 3min as the detection conditions, and relevant repeatability verification was carried out. The experimental results are shown in Figure 4 .

[0069] Results and Discussion

[0070] 1. Tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide is not easily soluble in water and has a high viscosity. It is immiscible with water. Therefore, DMSO with a higher polarity is selected as the solvent for testing, and the test results have better repeatability.

[0071] 2. By adjusting the gradient point of the program temperature rise and the stabilization time, the detection time is greatly reduced and the efficiency is increased by 60% while ensuring the stability of the thermal stability results.

[0072] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A qualitative analysis method for fluorine-containing quaternary ammonium salt ionic liquids, characterized in that: The steps include: S1. Preparation of samples to be tested: Add the sample to be tested into the NMR tube, then add the deuterated reagent, fully dissolve and set aside; S2. Parameter inspection before using the NMR spectrometer: liquid helium ≥ 40%, liquid nitrogen ≥ 40%, the automatic sampler is connected to the NMR intact, and the standard sample uniform field results meet the instrument requirements; The temperature of the differential thermal analyzer is within 0~600℃; S3. Use nuclear magnetic resonance spectrometer and differential thermal analyzer to perform testing in accordance with the instrument usage requirements.

2. The qualitative analysis method of a fluorine-containing quaternary ammonium salt ionic liquid according to claim 1, characterized in that: The specifications of the NMR tube used in S1 are: Φ5mm*20cm, made of glass.

3. A qualitative analysis method for a fluorine-containing quaternary ammonium salt ionic liquid according to claim 1, characterized in that: The sample to be tested in S1 is a fluorine-containing quaternary ammonium salt ionic liquid.

4. A qualitative analysis method for a fluorine-containing quaternary ammonium salt ionic liquid according to claim 3, characterized in that: The fluorine-containing quaternary ammonium salt ionic liquid is tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide.

5. The qualitative analysis method of a fluorine-containing quaternary ammonium salt ionic liquid according to claim 1, characterized in that: The deuterated reagent in S1 is DMSO.

6. The qualitative analysis method of a fluorine-containing quaternary ammonium salt ionic liquid according to claim 1, characterized in that: The amount of sample to be tested in S1 is 5-8 mg, and the amount of deuterated reagent added is 0.6 mL.

7. The qualitative analysis method of a fluorine-containing quaternary ammonium salt ionic liquid according to claim 1, characterized in that: In S2, when using a differential thermal analyzer for thermogravimetric analysis, no sample pretreatment is required, a programmed temperature is used, and the atmosphere is N2; the standard sample uniform field result meets the instrument requirements: Fina1 B0<1.

8. The qualitative analysis method of a fluorine-containing quaternary ammonium salt ionic liquid according to claim 1, characterized in that: The nuclear magnetic resonance spectrometer in S2 is manufactured by Bruker of Germany, model 400MHz; the differential thermal analyzer is manufactured by Mettler, model: TGA2.

9. The qualitative analysis method of a fluorine-containing quaternary ammonium salt ionic liquid according to claim 1, characterized in that: The detection conditions of the NMR spectrometer in S3 are as follows: 13 C:DS=2~4,NS=1024,D1=0~2,O1P=+100ppm 19 F:DS=2~4,NS=16,D1=0~2,O1P=-100ppm 1 H:DS=2~4,NS=16,D1=0~2,O1P=+4.2ppm; Analysis time: 15 minutes.

10. The qualitative analysis method of a fluorine-containing quaternary ammonium salt ionic liquid according to claim 1, characterized in that: The differential thermal analyzer detection conditions in S3 are as follows: The gradient heating rate is constant, and the heating gradient is: 180℃~300℃~430℃~450℃.

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