Establishment of nuclear magnetic resonance analysis method for chemical composition and condensed-state structure of fluorine-containing materials and its application

Abstract

This disclosure provides a nuclear magnetic resonance (NMR) analysis method for establishing the chemical composition and condensed-state structure of fluorine-containing materials and its application. The method includes: placing fluorine-containing materials under different operating conditions in a single-sided NMR spectrometer; under a single-sided inhomogeneous magnetic field environment; presetting parameters for a spin echo pulse sequence; using the spin echo pulse sequence to excite fluorine and hydrogen nuclei in the fluorine-containing material to obtain coupled NMR signals of fluorine and hydrogen nuclei; determining echo peak data from the coupled NMR signals according to the preset parameters; processing the echo peak data according to the structural characteristics of the fluorine-containing material to obtain relaxation spectrum fingerprint data; performing data transformation on the relaxation spectrum fingerprint data to obtain transverse relaxation time data; and establishing a relaxation spectrum fingerprint database and a transverse relaxation time database of the coupling of fluorine and hydrogen nuclei in the fluorine-containing material based on the relaxation spectrum fingerprint data and transverse relaxation time data under different operating conditions.

Description

Technical Field

[0001] This disclosure relates to the field of rapid detection technology for fluorine-containing materials, and in particular to a nuclear magnetic resonance (NMR) analysis method for establishing the chemical composition and condensed-state structure of fluorine-containing materials and its application. More specifically, it relates to an NMR analysis method for establishing the chemical composition and condensed-state structure of fluorine-containing materials, an NMR analysis method for establishing the chemical composition and condensed-state structure of fluorine-containing materials, and the application of the NMR analysis method in the performance testing of fluorine-containing materials. Background Technology

[0002] With the rapid development of science and technology, fluorine-containing materials, due to their unique chemical stability and excellent physical properties, have shown broad application prospects in high-end manufacturing fields such as aerospace, electronics and electrical engineering, new energy batteries, biomedicine, weapons manufacturing and packaging.

[0003] However, the rapid development in these fields has placed more stringent demands on the quality stability of fluorinated materials. Currently, the main analytical testing methods, such as density methods, grayscale methods, and mechanical strength tests, while capable of assessing the macroscopic quality of materials to some extent, are time-consuming and cannot meet the needs of rapid testing in large-scale production, thus limiting production efficiency and market response speed. Furthermore, existing methods typically only provide overall, macroscopic quality assessment results and cannot quickly and effectively analyze subtle differences that may exist between batches of materials. Therefore, further research is needed on analytical testing methods for fluorinated materials to overcome these current challenges. Summary of the Invention

[0004] In view of this, in order to partially solve one of the aforementioned technical problems, this disclosure provides a nuclear magnetic resonance analysis method for establishing the chemical composition and condensed-state structure of fluorine-containing materials and its application.

[0005] According to one embodiment of this disclosure, a nuclear magnetic resonance (NMR) analysis method for establishing the chemical composition and condensed-state structure of fluorine-containing materials is provided, comprising:

[0006] Fluorine-containing materials under different working conditions were placed in a single-sided nuclear magnetic resonance spectrometer. Under a single-sided non-uniform magnetic field environment, the parameters of the spin echo pulse sequence were preset, and the fluorine nuclei and hydrogen nuclei in the fluorine-containing materials were excited by the spin echo pulse sequence to obtain the coupled nuclear magnetic resonance signal of the fluorine nuclei and hydrogen nuclei.

[0007] Based on the parameters of the preset spin echo pulse sequence, the echo peak point data are determined from the coupled nuclear magnetic resonance signal.

[0008] Based on the structural characteristics of fluorine-containing materials, data processing is performed on the echo peak point data to obtain the relaxation spectrum fingerprint data of fluorine-containing materials;

[0009] Data transformation was performed on the obtained relaxation spectrum fingerprint data of fluorine-containing materials to obtain transverse relaxation time data of fluorine-containing materials;

[0010] Based on relaxation spectrum fingerprint data and transverse relaxation time data under different working conditions, a relaxation spectrum fingerprint database and a transverse relaxation time database for the coupling of fluorine nuclei and hydrogen nuclei in fluorine-containing materials are established.

[0011] The relaxation fingerprint data includes the component content and transverse relaxation time of the fluorine-containing material; the transverse relaxation time data includes the component ratio and kinetic distribution of the fluorine-containing material.

[0012] As another aspect of this disclosure, a nuclear magnetic resonance analysis method for the chemical composition and condensed-state structure of fluorine-containing materials is provided, comprising:

[0013] The fluorine-containing material to be tested is placed in a single-sided nuclear magnetic resonance spectrometer. Under a single-sided non-uniform magnetic field environment, the parameters of the spin echo pulse sequence are preset. The spin echo pulse sequence is used to excite the fluorine and hydrogen nuclei in the fluorine-containing material to obtain the coupled nuclear magnetic resonance signal of fluorine and hydrogen atoms in the fluorine-containing material to be tested.

[0014] Based on the parameters of the preset spin echo pulse sequence, the echo peak point data are determined from the coupled nuclear magnetic resonance signal.

[0015] Based on the structural characteristics of the fluorine-containing material to be tested, the echo peak point data is processed to obtain the relaxation spectrum fingerprint data of the fluorine-containing material to be tested.

[0016] The relaxation spectrum fingerprint data of the fluorine-containing material to be tested were transformed to obtain the transverse relaxation time data of the fluorine-containing material to be tested.

[0017] The relaxation spectrum fingerprint data and transverse relaxation time data of the coupling of fluorine nuclei and hydrogen nuclei in the fluorine-containing material to be tested are compared with the relaxation spectrum fingerprint database and transverse relaxation time database of the coupling of fluorine nuclei and hydrogen nuclei in fluorine-containing materials under different working conditions to determine the quality of the fluorine-containing material to be tested or to analyze the chemical composition and condensed state structure of the fluorine-containing material to be tested.

[0018] As another aspect of this disclosure, an application of the above-described NMR analysis method in the performance testing of fluorine-containing materials is provided.

[0019] According to embodiments of this disclosure, a nuclear magnetic resonance (NMR) analysis method is provided for establishing the chemical composition and condensed-state structure of fluorine-containing materials, enabling rapid characterization of these materials. Utilizing the magnetic field gradient of unilateral NMR, coupled NMR signals of fluorine and hydrogen nuclei are simultaneously acquired using a single radio frequency signal, thereby improving analytical efficiency. Furthermore, data processing is performed on the coupled NMR signals of fluorine and hydrogen nuclei to establish a relaxation spectrum fingerprint database and a transverse relaxation time database for the coupling of fluorine and hydrogen nuclei in the fluorine-containing materials, thus achieving rapid characterization of the chemical composition and condensed-state structure of these materials. Attached Figure Description

[0020] Figure 1 It shows the classification of nuclear magnetic resonance (NMR) instruments and the characteristic diagram of a single-sided NMR instrument;

[0021] Figure 2 This is a schematic diagram of the structure of a single-sided nuclear magnetic resonance spectrometer and its signal acquisition principle.

[0022] Figure 3 This is a diagram illustrating the process of determining echo peak points from coupled nuclear magnetic resonance signals in this disclosure;

[0023] Figure 4 This is a diagram illustrating the thickness direction detection process of fluorine-containing materials in this disclosure;

[0024] Figure 5a This is a graph showing the echo peak data of different batches of tetrafluoroethylene raw materials in Implementation Example 1 of this disclosure;

[0025] Figure 5b This is a fitted curve diagram of batch 39 tetrafluoroethylene raw material in Implementation Example 1 of this disclosure;

[0026] Figure 5c This is the spectrum of the relaxation spectral fingerprint data of batch 39 tetrafluoroethylene raw material in Example 1 of this disclosure after inverse Laplace transform;

[0027] Figure 6 This is a diagram of the device for online detection of the sample to be tested and a fitting curve diagram in Example 1 of this disclosure;

[0028] Figure 7 This is the spectrum of the relaxation spectral fingerprint data of the sample to be tested in Implementation Example 1 of this disclosure after inverse Laplace transform;

[0029] Figure 8 This is a graph showing the echo peak data of the three adhesive materials in Embodiment 2 of this disclosure;

[0030] Figure 9 This is a one-dimensional profile of the proton exchange membrane in the thickness direction of Embodiment 3 of this disclosure. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments.

[0032] The endpoints and any values ​​of the ranges disclosed in this disclosure are not limited to the precise ranges or values, and such ranges or values ​​should be understood to include values ​​close to such ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this disclosure.

[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0034] Nuclear Magnetic Resonance (NMR) technology, as a result of the interaction between electromagnetic waves and matter, plays a crucial role in exploring the microscopic structure and properties of matter. The basic principle of NMR is that atomic nuclei with non-zero spin quantum numbers align their magnetic moments along the direction of a static magnetic field B0. The angular frequency ω0 of the precession of the magnetic moment around B0 is the Larmor precession frequency, the magnitude of which is related to the nucleus being detected, where ω0 = γ × B0. During NMR detection, resonance occurs when the static magnetic field B1 applied by the radio frequency coil matches the Larmor precession frequency of the detected nucleus. The applied static magnetic field exchanges energy with the nucleus, generating a resonance signal that allows for in-depth exploration of the nucleus and its surrounding environment. However, traditional NMR equipment is limited by the uniform magnetic field region generated by the radio frequency coil, resulting in a limited testing space and suitability only for small-volume samples. For example, the diameter of high-field solid nucleus sample tubes is only 3-4 mm, and the diameter of low-field NMR samples is approximately 10 mm, limiting the detection area. Furthermore, in real-world applications, many samples cannot be brought to the laboratory for analysis, or cannot be sampled for analysis.

[0035] Figure 1 This section describes the classification of nuclear magnetic resonance (NMR) instruments and provides characteristic diagrams of single-sided NMR instruments. For example... Figure 1As shown, in realizing this disclosure, it was discovered that conventional NMR requires a uniform static magnetic field to excite the atomic nuclei in the sample, but this is limited by the size of the uniform magnetic field region generated by the radio frequency coil. Low-field NMR uses a lower magnetic field strength but focuses more on the macroscopic properties of the sample, such as porosity, water content, and molecular dynamics. Single-sided NMR, by placing the magnet and detection coil on one side of the sample, enables non-destructive online detection of objects of arbitrary volume without sample preparation, providing possibilities for on-site detection and analysis of large objects. Under non-uniform magnetic field conditions, the spin system spectral width of large-volume samples may exceed the effective coverage of the radio frequency field, causing traditional radio frequency pulses to become selective pulses, increasing the complexity of the analysis.

[0036] Figure 2 This is a schematic diagram of the structure of a single-sided nuclear magnetic resonance spectrometer and its signal acquisition principle.

[0037] like Figure 2 As shown, the sample is placed in a static magnetic field with a magnetic field gradient. Hydrogen and fluorine nuclei in the sample undergo Larmor precession along the direction of the static magnetic field. Normally, due to the different gyromagnetic ratios of hydrogen and fluorine, their precession frequencies differ even under the same magnetic field strength, requiring multi-channel (multi-RF signal) detection for different elements. However, due to the inherent gradient magnetic field of the single-sided NMR, hydrogen and fluorine atoms at different positions have the same precession frequency. This allows them to be simultaneously excited in the same detection coil and distinguished based on their position. By adjusting the RF pulse to match the hydrogen atom precession frequency, the frequencies of multiple elements' NMR signals can be simultaneously acquired through a single channel (single RF signal), thereby enabling rapid analysis of the sample's chemical and structural properties.

[0038] To address this, this disclosure proposes a nuclear magnetic resonance (NMR) analysis method for establishing the chemical composition and condensed-state structure of fluorine-containing materials, enabling rapid characterization of their chemical composition and condensed-state structure. Utilizing the magnetic field gradient of a single-sided NMR signal, and through excitation with a single radio frequency signal, it is possible to simultaneously capture fluorine nuclei (fluorine atoms) in fluorine-containing materials. 19 F) and hydrogen nucleus ( 1 H) Coupled NMR signals at different locations significantly improve analytical efficiency. Furthermore, the coupled NMR signals of fluorine and hydrogen nuclei are processed to construct a relaxation spectral fingerprint database and a transverse relaxation time database for the coupling of fluorine and hydrogen nuclei in fluorine-containing materials, thereby enabling rapid characterization of the chemical composition and condensed-state structure of these materials. In addition, this method utilizes a magnetic field gradient for in-situ characterization of materials, eliminating the need for sample taking or pretreatment, achieving non-destructive testing. Moreover, it has no specific requirements on sample volume and mass, further enhancing its practicality and convenience.

[0039] According to one embodiment of this disclosure, a nuclear magnetic resonance analysis method for establishing the chemical composition and condensed-state structure of fluorine-containing materials is provided, comprising:

[0040] Fluorine-containing materials under different working conditions were placed in a single-sided nuclear magnetic resonance spectrometer. Under a single-sided non-uniform magnetic field environment, the parameters of the spin echo pulse sequence were preset, and the fluorine nuclei and hydrogen nuclei in the fluorine-containing materials were excited by the spin echo pulse sequence to obtain the coupled nuclear magnetic resonance signal of the fluorine nuclei and hydrogen nuclei.

[0041] Based on the parameters of the preset spin echo pulse sequence, the echo peak point data are determined from the coupled nuclear magnetic resonance signal.

[0042] Based on the structural characteristics of fluorine-containing materials, data processing is performed on the echo peak point data to obtain the relaxation spectrum fingerprint data of fluorine-containing materials;

[0043] Data transformation was performed on the obtained relaxation spectrum fingerprint data of fluorine-containing materials to obtain transverse relaxation time data of fluorine-containing materials;

[0044] Based on relaxation spectrum fingerprint data and transverse relaxation time data under different working conditions, a relaxation spectrum fingerprint database and a transverse relaxation time database for the coupling of fluorine nuclei and hydrogen nuclei in fluorine-containing materials are established.

[0045] The relaxation fingerprint data includes the component content and transverse relaxation time of the fluorine-containing material; the transverse relaxation time data includes the component ratio and kinetic distribution of the fluorine-containing material.

[0046] According to embodiments of this disclosure, a nuclear magnetic resonance (NMR) analysis method is provided for establishing the chemical composition and condensed-state structure of fluorine-containing materials, enabling rapid characterization of these materials. Utilizing the inhomogeneous gradient magnetic field of unilateral NMR, fluorine and hydrogen nuclei in the fluorine-containing material are excited under a single radio frequency (RF) signal. This allows for the simultaneous acquisition of coupled NMR signals of fluorine and hydrogen nuclei using a single RF signal, thereby improving the efficiency of data acquisition and analysis. Furthermore, the coupled NMR signals of fluorine and hydrogen nuclei are processed to construct a relaxation spectrum fingerprint database and a transverse relaxation time database for the coupling of fluorine and hydrogen nuclei in the fluorine-containing material. These databases are used to characterize the chemical composition and condensed-state structure of the fluorine-containing material and serve as a rapid reference for material properties, thus achieving rapid characterization of the chemical composition and condensed-state structure of fluorine-containing materials.

[0047] According to embodiments of this disclosure, fluorinated materials under different operating conditions include: fluorinated materials from different batches; and / or fluorinated materials at different service stages. For example, in engineering fluoroplastics manufacturing applications, there are polytetrafluoroethylene (PTFE) materials manufactured in different production batches. These different batches may have different properties due to fluctuations in raw material sources and mixing or mismatching during the production process. In electronic device manufacturing, there are fluorinated rubber seals at different service stages (e.g., initial, middle, and final stages), whose performance may change during use due to factors such as wear, aging, or chemical corrosion. By studying fluorinated materials under different operating conditions, the quality, stability, reliability, and other properties of the materials can be analyzed.

[0048] According to embodiments of this disclosure, fluorine-containing materials under different operating conditions are placed in a single-sided nuclear magnetic resonance spectrometer. Under a unilateral non-uniform magnetic field environment, by pre-setting parameters for a spin echo pulse sequence, the fluorine and hydrogen nuclei in the fluorine-containing material are excited using the spin echo pulse sequence to obtain coupled nuclear magnetic resonance signals of the fluorine and hydrogen nuclei. The parameters of the pre-set spin echo pulse sequence include: radio frequency pulse width, repetition acquisition time, scan echo time, number of echoes, acquisition time, and number of scans. The preferred spin echo pulse sequence is a CPMG (Carr-Purcell-Meiboom-Gill) pulse sequence. For example, when analyzing polytetrafluoroethylene (PTFE) materials, a CPMG pulse sequence was used, with a radio frequency pulse width of 10 μs, a repetition acquisition time of 350 ms, a scan echo time of 44 μs, 100 echoes, an acquisition time of 10 μs, and 300 scans. When analyzing fluorinated proton exchange membranes, a CPMG pulse sequence was used, with a radio frequency pulse width of 6 μs, a repetition acquisition time of 200 ms, a scan echo time of 47 μs, 256 echoes, an acquisition time of 20 μs, and 512 scans. The preset spatial resolution was 50 μm. The coupled NMR signal between fluorine and hydrogen nuclei is the coupling of the NMR signal of fluorine nuclei with that of hydrogen nuclei; where the coupled NMR signal of fluorine and hydrogen nuclei is expressed as: δ = δ H +δ F Where δ is the chemical shift of the coupling signal, δ H δ represents the chemical shift of the hydrogen nucleus in fluorine-containing materials. F This represents the chemical shift of fluorine nuclei in fluorine-containing materials.

[0049] In the embodiments of this disclosure, the fluorine-containing material is excited by utilizing the magnetic field gradient effect in unilateral nuclear magnetic resonance (NMR) technology. Then, under the action of a single radio frequency (RF) signal, the coupled NMR signals of fluorine nuclei and hydrogen nuclei can be acquired simultaneously using a single signal, thereby improving the efficiency of the analysis process.

[0050] According to embodiments of this disclosure, echo peak point data are determined from coupled nuclear magnetic resonance signals based on parameters of a preset spin echo pulse sequence.

[0051] Figure 3 This is a diagram illustrating the process of determining echo peak points from coupled nuclear magnetic resonance signals in this disclosure. (See diagram for example.) Figure 3 As shown, a 90-degree pulse is applied first, followed by a 180-degree pulse to achieve phase refocusing of the transverse magnetization flux and obtain the echo signal. By continuing to apply a 180-degree radio frequency pulse, the spin echo signal can be detected. Based on the preset echo pulse sequence parameters, the echo peak point data can be determined and acquired.

[0052] According to embodiments of this disclosure, different structural features affect the arrangement and movement of polymer chains in materials, thereby affecting the nuclear magnetic resonance (NMR) signal of fluorine-containing materials. Therefore, it is necessary to process the echo peak data based on the structural features of the fluorine-containing material to obtain relaxation spectral fingerprint data. Specifically, this includes determining and processing the echo peak data according to the structural features of the fluorine-containing material to obtain its relaxation spectral fingerprint data. The structural features of the fluorine-containing material are semi-crystalline polymers or cross-linked polymers. Semi-crystalline polymers and cross-linked polymers have significantly different molecular structures and dynamic behaviors. By determining the data processing method based on the structural features of the fluorine-containing material, the relaxation spectral fingerprint data of the coupling between fluorine and hydrogen nuclei in the fluorine-containing material can be accurately obtained. The data processing methods include two-component fitting or one-component fitting, and data fitting is performed based on different fitting tools, preferably conventional mathematical fitting tools.

[0053] According to embodiments of this disclosure, when the fluorinated material has the structural characteristic of a semi-crystalline polymer, such as polytetrafluoroethylene (PTFE), fluorinated resin F2314, fluorinated resin F2311, and perfluorosulfonic acid (PFSA), etc., the semi-crystalline polymer contains two components: a rigid phase (crystalline phase) and a flexible phase (amorphous phase). By using a two-component fitting method to process the echo peak data, the content of the two components and their respective transverse relaxation times can be distinguished and quantified, obtaining relaxation spectrum fingerprint data of the fluorinated material, further characterizing the microstructure and phase distribution of the fluorinated material. Furthermore, the two components include: a rigid phase component and a flexible phase component, and the relaxation spectrum fingerprint data includes: the content of the rigid phase component, the content of the flexible phase component, the transverse relaxation time of the rigid phase, and the transverse relaxation time of the flexible phase of the fluorinated material.

[0054] Specifically, the two-component fitting method is expressed as follows:

[0055]

[0056] in, The acquisition time for the coupled nuclear magnetic resonance signal;

[0057] For fluorine-containing materials, the collection time is The intensity of the coupled nuclear magnetic resonance signal at any given time;

[0058] For fluorine-containing materials in Initial coupled nuclear magnetic resonance signal intensity when =0;

[0059] This refers to the content of the rigid phase component in fluorine-containing materials;

[0060] This refers to the content of the flexible phase component in fluorine-containing materials;

[0061] , where is the transverse relaxation time of the rigid phase of the fluorine-containing material;

[0062] The transverse relaxation time of the flexible phase of the fluorine-containing material;

[0063] The structural factor for the rigid phase of fluorine-containing materials;

[0064] The structural factor is the flexible phase of the fluorine-containing material.

[0065] The relaxation spectrum fingerprint data of the obtained fluorine-containing materials are transformed to obtain the transverse relaxation time data of the fluorine-containing materials. This includes: using the inverse Laplace transform to transform the relaxation spectrum fingerprint data to obtain the transverse relaxation time data of the fluorine-containing materials.

[0066] When the structure of the fluorinated material is a semi-crystalline polymer, the relaxation spectral fingerprint data of the fluorinated material, after inverse Laplace transform, yields a spectrum with two peaks, which represent the rigid phase and the flexible phase in the fluorinated material, respectively.

[0067] At this point, the lateral relaxation time data includes:

[0068] Peak positions of the two peaks: relaxation time of the rigid and flexible phase components of the fluorinated material;

[0069] Peak areas of the two peaks; component ratio of the rigid phase and the flexible phase of the fluorinated material;

[0070] Half-width at half-maximum (HWHM) of the two peaks: the dynamic distribution of the rigid phase and the dynamic distribution of the flexible phase. The wider the HWHM, the wider the distribution of the dynamic characteristics of the phase.

[0071] According to embodiments of this disclosure, when the structural feature of the fluorinated material is a cross-linked polymer, such as fluororubber (FKM), fluorosilicone rubber (FVMQ), and fluorinated synthetic rubber (FFKM), the cross-linked polymer structure can be considered as a single flexible phase. A single-component fitting method is used to process the echo peak data to obtain relaxation spectral fingerprint data of the fluorinated material, thereby characterizing its overall structural properties. The single component is the flexible phase component, and the relaxation spectral fingerprint data includes the component content of the flexible phase and the transverse relaxation time of the flexible phase.

[0072] The single-component fitting method is expressed as:

[0073]

[0074] The relaxation spectrum fingerprint data of the obtained fluorine-containing materials are transformed to obtain the transverse relaxation time data of the fluorine-containing materials. This includes: using the inverse Laplace transform to transform the relaxation spectrum fingerprint data to obtain the transverse relaxation time data of the fluorine-containing materials.

[0075] When the structural characteristics of the fluorinated material are cross-linked polymers, the relaxation spectral fingerprint data of the fluorinated material, after inverse Laplace transform, yields a spectrum with a single peak. The single peak in the spectrum represents the flexible phase in the fluorinated material.

[0076] At this point, the lateral relaxation time data includes:

[0077] Peak positions of the two peaks: relaxation time, a kinetic characteristic of the flexible phase component in fluorinated materials;

[0078] Peak area of ​​a single peak: a component of the flexible phase in fluorine-containing materials;

[0079] Half-peak width (HWHM) of a single peak: the kinetic distribution of the rigid phase of the fluorine-containing material. Here, the kinetic distribution refers to the range of time required for the component's motion state to change.

[0080] According to another embodiment of this disclosure, a nuclear magnetic resonance analysis method for the chemical composition and condensed-state structure of fluorine-containing materials is provided, comprising:

[0081] The fluorine-containing material to be tested is placed in a single-sided nuclear magnetic resonance spectrometer. Under a single-sided non-uniform magnetic field environment, the parameters of the spin echo pulse sequence are preset. The spin echo pulse sequence is used to excite the fluorine nuclei and hydrogen nuclei in the fluorine-containing material to obtain the coupled nuclear magnetic resonance signal of the fluorine nuclei and hydrogen nuclei in the fluorine-containing material to be tested.

[0082] Based on the parameters of the preset spin echo pulse sequence, the echo peak point data are determined from the coupled nuclear magnetic resonance signal.

[0083] Based on the structural characteristics of the fluorine-containing material to be tested, the echo peak point data is processed to obtain the relaxation spectrum fingerprint data of the fluorine-containing material to be tested.

[0084] The relaxation spectrum fingerprint data of the fluorine-containing material to be tested were transformed to obtain the transverse relaxation time data of the fluorine-containing material to be tested.

[0085] The relaxation spectrum fingerprint data and transverse relaxation time data of the coupling of fluorine nuclei and hydrogen nuclei in the fluorine-containing material to be tested are compared with the relaxation spectrum fingerprint database and transverse relaxation time database of the coupling of fluorine nuclei and hydrogen nuclei in fluorine-containing materials under different operating conditions to determine the quality of the fluorine-containing material to be tested or to analyze the chemical composition and condensed state structure of the fluorine-containing material to be tested.

[0086] According to embodiments of this disclosure, by comparing the relaxation spectrum fingerprint data and transverse relaxation time data of the coupling of fluorine and hydrogen nuclei in the fluorine-containing material under test with established databases of relaxation spectrum fingerprint data and transverse relaxation time data of fluorine and hydrogen nuclei coupling under different operating conditions, the chemical composition characteristics and subtle differences in the condensed-state structure of the fluorine-containing material under test can be efficiently identified. This not only provides a non-destructive testing method but also significantly improves the analysis speed, enabling rapid analysis and evaluation of the performance of fluorine-containing materials.

[0087] According to embodiments of this disclosure, the aforementioned nuclear magnetic resonance analysis method further includes: performing material characterization tests on fluorine-containing materials under different operating conditions to obtain test results; and, based on the test results, classifying the data in the relaxation spectrum fingerprint database and the transverse relaxation time database of fluorine nuclei and hydrogen nuclei coupling. The test methods include one or more of infrared spectroscopy, scanning electron microscopy, and X-ray computed tomography (CT). Material properties include: the service stage level, quality level, and failure level of the fluorine-containing material. For example, infrared spectroscopy and scanning electron microscopy are used to test fluorine-containing materials at different service stages (1-3 years, 3-6 years, and 6-10 years of service). Based on the results of the infrared spectroscopy and scanning electron microscopy images, the data in the relaxation spectrum fingerprint database and the transverse relaxation time database of the fluorine-containing materials at different service stages are classified as primary (1-3 years of service), intermediate (3-6 years of service), and final (6-10 years of service).

[0088] According to another embodiment of this disclosure, an application of the above-described NMR analysis method in the performance analysis of fluorine-containing materials is provided.

[0089] According to embodiments of this disclosure, the performance analysis of fluorine-containing materials includes: determining the quality of the fluorine-containing material to be tested.

[0090] For example, materials testing methods are used to classify and distinguish between qualified and unqualified products by using a relaxation spectrum fingerprint database and / or a transverse relaxation time database of fluorine and hydrogen nuclei coupling in different batches of fluorine-containing materials, and to determine the error range for qualified products. The relaxation spectrum fingerprint data and transverse relaxation time data of the fluorine and hydrogen nuclei coupling in the fluorine-containing material to be tested are compared with the relaxation spectrum fingerprint database and transverse relaxation time database of fluorine and hydrogen nuclei coupling in different batches of fluorine-containing materials. Based on the comparison results, it is determined whether the fluorine-containing material to be tested is within the error range for qualified products. Samples within the error range are considered qualified; those exceeding the error range are considered unqualified.

[0091] According to embodiments of this disclosure, the performance analysis of fluorine-containing materials includes: analyzing the service status of the fluorine-containing materials.

[0092] For example, material testing methods are used to classify the service status of fluorine-containing materials at different service stages by using relaxation spectrum fingerprint databases and / or transverse relaxation time databases of fluorine nuclei coupling between fluorine and hydrogen nuclei. The relaxation spectrum fingerprint data and transverse relaxation time data of the fluorine-containing material to be tested are compared with the relaxation spectrum fingerprint databases and transverse relaxation time databases of fluorine nuclei coupling between fluorine and hydrogen nuclei of different batches of fluorine-containing materials. Based on the comparison results, the service status of the fluorine-containing material to be tested is analyzed.

[0093] According to embodiments of this disclosure, the performance analysis of fluorine-containing materials includes: distinguishing the chemical composition of the fluorine-containing materials.

[0094] For example, the relaxation spectrum fingerprint data and transverse relaxation time data of the coupling of fluorine nuclei and hydrogen nuclei in the fluorine-containing material to be tested are compared with the relaxation spectrum fingerprint database and transverse relaxation time database of the coupling of fluorine nuclei and hydrogen nuclei in fluorine-containing materials with different chemical compositions. Based on the comparison results, the chemical composition of the fluorine-containing material can be distinguished.

[0095] Furthermore, by using unilateral nuclear magnetic resonance combined with a thickness-direction displacement device, it is also possible to detect the thickness direction of fluorine-containing materials and characterize the thickness change of a certain component of fluorine-containing materials during service.

[0096] Figure 4 This is a diagram illustrating the thickness direction detection process of fluorine-containing materials in this disclosure.

[0097] like Figure 4As shown, by combining a single-sided nuclear magnetic resonance (NMR) spectrometer with a displacement device, the thickness direction of fluorine-containing materials can be detected and analyzed. The sample is placed on a detection platform in a static magnetic field environment with a magnetic field gradient. The probe on the movable displacement device controls the detection position. By controlling the displacement device, coupled NMR signals of fluorine and hydrogen nuclei can be excited and captured at different thickness locations of the fluorine-containing material. Through data processing of the coupled NMR signals, a contour map of the thickness direction of the fluorine-containing material is further constructed, enabling the detection and analysis of the thickness direction of the fluorine-containing material.

[0098] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments. Unless otherwise specified, all methods described in the embodiments are conventional and can be performed according to the techniques or conditions described in the literature or the product manual.

[0099] Example 1:

[0100] In the aerospace field, the protective layer of cables and optical fibers is crucial for ensuring the reliability of equipment under extreme conditions. The protective layer material is typically made of fluorinated materials such as tetrafluoroethylene (PTFE). Batch-to-batch variations or mixing errors in PTFE raw materials can significantly affect the mechanical strength of cables in high and low temperature environments (-55℃ to 180℃). Therefore, Example 1 provides a nuclear magnetic resonance analysis method for the chemical composition and condensed-state structure of fluorinated materials to analyze the quality of PTFE raw materials. Specifically, it includes the following steps:

[0101] Step 1: Samples of each batch of PTFE raw material obtained from production were taken. Different batches of PTFE raw material were placed in a single-sided nuclear magnetic resonance (NMR) spectrometer. Under a single-sided non-uniform magnetic field environment, the parameters of the spin echo pulse sequence were preset as follows: radio frequency pulse width of 10 μs, repetition acquisition time of 350 ms, scan echo time of 44 μs, number of echoes of 100, acquisition time of 10 μs, and number of scans of 300. The spin echo pulse sequence was used to excite the fluorine and hydrogen nuclei in the fluorine-containing material to obtain coupled NMR signals of the fluorine and hydrogen nuclei.

[0102] Step 2: Determine the echo peak point data from the coupled nuclear magnetic resonance signal based on the parameters of the preset spin echo pulse sequence. Figure 5a This is a graph showing the echo peak data of different batches of tetrafluoroethylene raw materials in Implementation Example 1 of this disclosure;

[0103] Step 3: Perform two-component fitting on the echo peak data. The two-component fitting method is as follows:

[0104]

[0105] in, The acquisition time for the coupled nuclear magnetic resonance signal;

[0106] For PTFE raw materials, the collection time is The strength of the coupled signal at any given moment;

[0107] For PTFE raw materials in Initial signal strength when =0;

[0108] This refers to the content of rigid phase components in the PTFE raw material;

[0109] This refers to the content of the flexible phase component in the PTFE raw material;

[0110] The transverse relaxation time of the rigid phase of the PTFE raw material;

[0111] The transverse relaxation time of the flexible phase of the PTFE raw material;

[0112] The structural factor is the rigid phase of the PTFE-containing raw material;

[0113] The structural factor is the flexible phase of the PTFE raw material.

[0114] The relaxation fingerprint data of PTFE raw material is obtained, which includes the component content of the rigid phase, the component content of the flexible phase, the transverse relaxation time of the rigid phase, and the transverse relaxation time of the flexible phase.

[0115] Figure 5b This is a fitted curve diagram of batch 39 tetrafluoroethylene raw material in Implementation Example 1 of this disclosure, as shown below. Figure 5b As shown, taking batch 39 as an example, the PTFE raw material of batch 39 was subjected to two-component fitting using the following formula to obtain the corresponding fitting curve and relaxation spectrum fingerprint data of the PTFE raw material: the content of rigid phase component is 0.65, the content of flexible phase component is 0.35, and the transverse relaxation time of the rigid phase (T) is... 2r The transverse relaxation time (T) of the flexible phase is 0.077 ms. 2m The time taken was 0.96ms.

[0116] Step 4: Perform inverse Laplace transform on the relaxation fingerprint data of PTFE raw material to obtain transverse relaxation time data of fluorine-containing materials;

[0117] Figure 5cThis is the spectrum of the relaxation spectral fingerprint data of batch 39 tetrafluoroethylene raw material in Example 1 of this disclosure after inverse Laplace transform, as shown below. Figure 5c As shown, taking batch 39 as an example, by performing an inverse Laplace transform on the PTFE raw material of batch 39, the corresponding spectrum and transverse relaxation time data of the PTFE raw material were obtained: rigid peak area is 0.87, flexible peak area is 0.20, rigid peak peak position is 0.31ms, flexible peak peak position is 1.19ms, rigid peak half-width is 0.69, and flexible peak half-width is 0.33.

[0118] Step 5: Based on the relaxation spectrum fingerprint data and transverse relaxation time data of different batches of PTFE raw materials, establish a relaxation spectrum fingerprint database and a transverse relaxation time database for the coupling of fluorine nuclei and hydrogen nuclei in fluorine-containing materials. Record the relaxation spectrum fingerprint database data in Table 1 and the transverse relaxation time database data in Table 2.

[0119] Table 1

[0120]

[0121] Continued from Table 1

[0122]

[0123] Table 2

[0124]

[0125] Continued from Table 2

[0126]

[0127] Based on the relaxation spectrum fingerprint database in Table 1, the qualified standards for PTFE raw materials are defined as follows: rigid phase content 62-67%, flexible phase content 33-38%, transverse relaxation time of rigid phase 0.05-0.08 ms, and transverse relaxation time of flexible phase 0.89-1.05 ms. Based on the transverse relaxation time database in Table 2, the qualified standards for PTFE raw materials are defined as follows: rigid peak area 0.82-0.99, flexible peak area 0.13-0.25, rigid peak peak position 0.28 ms-0.43 ms, flexible peak peak position 1.18 ms-1.20 ms, rigid peak half-width 0.53-0.87, and flexible peak half-width 0.22-0.47.

[0128] Step 6: Place the sample to be tested in a single-sided nuclear magnetic resonance spectrometer. Under a single-sided non-uniform magnetic field environment, use the same preset spin echo pulse sequence parameters as in Step 1 to excite the fluorine nuclei and hydrogen nuclei in the sample to obtain the coupled nuclear magnetic resonance signals of the fluorine nuclei and hydrogen nuclei.

[0129] Based on the parameters of the preset spin echo pulse sequence, the echo peak point data are determined from the coupled nuclear magnetic resonance signal.

[0130] A two-component fitting method was used to fit the echo peak point data to obtain the relaxation spectrum fingerprint data of the sample under test.

[0131] Figure 6 These are optical photographs and fitting curves of the sample under test during online detection in Example 1 of this disclosure.

[0132] Figure 7 This is the spectrum of the relaxation spectral fingerprint data of the sample to be tested in Implementation Example 1 of this disclosure after inverse Laplace transform.

[0133] like Figure 6 , Figure 7 As shown in Tables 1 and 2, the relaxation fingerprint data of the sample to be tested shows that the content of the rigid phase is 64%, the content of the flexible phase is 36%, the relaxation time of the rigid phase is 0.07 ms, and the relaxation time of the flexible phase is 0.95 ms. The area of ​​the rigid peak is 0.96, the area of ​​the flexible peak is 0.22, the peak position of the rigid peak is 0.33, the peak position of the flexible peak is 1.19, the half-width at half-maximum (WWHM) of the rigid peak is 0.60, and the WWHM of the flexible peak is 0.24. The relaxation fingerprint data of the sample to be tested is compared with the qualification standard of PTFE raw materials and meets the qualification standard, thus it can be approved for entry into the factory.

[0134] Example 2

[0135] Polymer-bonded explosives (PBXs) are characterized by high energy density, excellent stability, and ease of processing and molding. PBX explosives are mainly composed of polymers, binders, and other additives. The binders typically use fluoropolymers, such as PTFE binders, and fluoropolymers F2311 and F2314 binders. In F2311 and F2314 binders, the molar ratios of vinylidene fluoride (C2H2F2, VDF) to chlorotrifluoroethylene (C2ClF3, CTFE) are 1:1 and 1:4, respectively.

[0136] The molecular structures of fluoropolymer F2311 and F2314 adhesives are as follows:

[0137]

[0138] To avoid incorrect or mixed binder materials during production, this embodiment 2 provides a nuclear magnetic resonance (NMR) analysis method for the chemical composition and condensed-state structure of fluorine-containing materials, distinguishing the chemical composition of fluorine-containing materials. Specifically, it includes the following steps:

[0139] Step 1: Place three adhesive materials—PTFE adhesive, F2311 adhesive, and F2314 adhesive—into a single-sided NMR spectrometer. Under a single-sided inhomogeneous magnetic field environment, preset the parameters of the spin echo pulse sequence: radio frequency pulse width of 6 μs, repetition acquisition time of 500 ms, scan echo time of 30 μs, number of echoes of 100, acquisition time of 1 μs, and number of scans of 128. Use the spin echo pulse sequence to excite the fluorine nuclei and hydrogen nuclei in the three adhesives respectively, and obtain the corresponding coupled NMR signals of fluorine nuclei and hydrogen nuclei.

[0140] Step 2: Determine the echo peak point data from the coupled nuclear magnetic resonance signal based on the parameters of the preset spin echo pulse sequence;

[0141] Step 3: The echo peak data of the three adhesives are processed using a two-component fitting method to obtain the relaxation spectrum fingerprint data of the three adhesives.

[0142] Figure 8 This is a graph showing the echo peak data of the three adhesive materials in Embodiment 2 of this disclosure.

[0143] like Figure 8 As shown, there are significant differences in the echo peak data of the three adhesive materials.

[0144] Step 4: Perform inverse Laplace transform on the relaxation spectral fingerprint data of the three binders respectively to obtain the transverse relaxation time data of the fluorine-containing materials;

[0145] Step 5: Establish a relaxation spectrum fingerprint database and a transverse relaxation time database for the coupling of fluorine and hydrogen nuclei in the three binder materials. The relaxation spectrum fingerprint data includes the component content of the rigid phase, the component content of the flexible phase, and the transverse relaxation time of the rigid and flexible phases for each of the PTFE, F2311, and F2314 binders. The transverse relaxation time database includes the component ratio of the rigid phase, the component ratio of the flexible phase, the kinetic distribution of the rigid phase, and the kinetic distribution of the flexible phase for each of the PTFE, F2311, and F2314 binders.

[0146] Step 6: Place the adhesive to be tested in a single-sided nuclear magnetic resonance spectrometer. Under a single-sided non-uniform magnetic field environment, use the same preset spin echo pulse sequence parameters as in Step 1 to excite the fluorine and hydrogen nuclei in the adhesive to be tested, and obtain the coupled nuclear magnetic resonance signals of the fluorine and hydrogen nuclei.

[0147] Based on the parameters of the preset spin echo pulse sequence, the echo peak point data are determined from the coupled nuclear magnetic resonance signal.

[0148] A two-component fitting method was used to fit the echo peak data to obtain the relaxation spectrum fingerprint data of the adhesive under test. An inverse Laplace transform was then performed on the relaxation spectrum fingerprint data to obtain the transverse relaxation time data. The relaxation spectrum fingerprint data and transverse relaxation time data of the adhesive under test were compared with relaxation spectrum fingerprint databases and transverse relaxation time databases for three different adhesive materials to quickly distinguish the type of adhesive under test.

[0149] Example 3

[0150] Hydrogen fuel cells generate electricity efficiently using redox reactions, offering significant advantages such as high efficiency, zero pollution, no noise, and zero carbon emissions. The proton exchange membrane (PEM) in hydrogen fuel cells is primarily made of perfluorosulfonic acid (PFSA). Currently, porous expanded polytetrafluoroethylene (e-PTFE) membranes are used as reinforcing matrices and combined with PFSA materials to prepare reinforced composite proton exchange membranes (RCMs). By introducing the mechanically more mechanically stable ePTFE material through composite formation, the total membrane thickness can be effectively reduced while maintaining the mechanical strength and dimensional stability of the proton exchange membrane. This reduces the use of PFSA ion-crosslinked polymers and lowers manufacturing costs. Example 3 provides a nuclear magnetic resonance (NMR) analysis method for the chemical composition and condensed-state structure of fluorine-containing materials to detect the thickness direction of e-PTFE and PFSA components in the proton exchange membrane, including the following steps:

[0151] Step 1: Place the proton exchange membrane to be tested in a single-sided NMR spectrometer. Under a single-sided inhomogeneous magnetic field environment, preset the parameters of the spin echo pulse sequence: radio frequency pulse width of 6 μs, repetition acquisition time of 200 ms, scan echo time of 47 μs, number of echoes of 256, acquisition time of 20 μs, number of scans of 512, and preset spatial resolution of 50 μm. Use the spin echo pulse sequence to excite the fluorine and hydrogen nuclei in the proton exchange membrane to be tested, respectively, to obtain the corresponding coupled NMR signals of the fluorine and hydrogen nuclei.

[0152] Step 2: Determine the echo peak point data from the coupled nuclear magnetic resonance signal based on the parameters of the preset spin echo pulse sequence;

[0153] Step 3: The echo peak data of the proton exchange membrane under test are processed using a two-component fitting method to obtain the relaxation spectral fingerprint data of the proton exchange membrane under test.

[0154] Step 4: Perform inverse Laplace transform on the relaxation spectrum fingerprint data of the proton exchange membrane to be tested to obtain the transverse relaxation time data of the proton exchange membrane to be tested.

[0155] The relaxation spectral fingerprint data includes the component content of the rigid phase, the component content of the flexible phase, the transverse relaxation time of the rigid phase, and the transverse relaxation time of the flexible phase of the proton exchange membrane under test; the transverse relaxation time data includes the component ratio of the rigid phase, the component ratio of the flexible phase, the kinetic distribution of the rigid phase, and the kinetic distribution of the flexible phase of the proton exchange membrane under test.

[0156] Step 5: Based on the transverse relaxation time data and the preset spatial resolution, generate a one-dimensional profile of the proton exchange membrane thickness direction, and analyze the thickness direction of the e-PTFE and PFSA components in the proton exchange membrane under test.

[0157] Figure 9 This is a one-dimensional profile of the proton exchange membrane in the thickness direction of Embodiment 3 of this disclosure.

[0158] like Figure 9 As shown, the chemical composition changes along the membrane thickness direction can be observed through a one-dimensional profile diagram, and the directional positions of fluorinated materials with different chemical components in the proton exchange membrane can be analyzed.

[0159] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A nuclear magnetic resonance (NMR) analysis method for establishing the chemical composition and condensed-state structure of fluorine-containing materials, comprising: Fluorine-containing materials under different working conditions were placed in a single-sided nuclear magnetic resonance spectrometer. Under a single-sided non-uniform magnetic field environment, the parameters of the spin echo pulse sequence were preset. The spin echo pulse sequence was used to excite the fluorine nuclei and hydrogen nuclei in the fluorine-containing materials. The coupled nuclear magnetic resonance signals of fluorine nuclei and hydrogen nuclei were obtained simultaneously by a single radio frequency signal. Based on the preset parameters of the spin echo pulse sequence, the echo peak point data are determined from the coupled nuclear magnetic resonance signal; Based on the structural characteristics of the fluorine-containing material, the echo peak point data is processed to obtain the relaxation spectrum fingerprint data of the fluorine-containing material; The relaxation spectrum fingerprint data of the obtained fluorine-containing material is transformed to obtain the transverse relaxation time data of the fluorine-containing material. Based on the relaxation spectrum fingerprint data and transverse relaxation time data under different working conditions, a relaxation spectrum fingerprint database and a transverse relaxation time database for the coupling of fluorine nuclei and hydrogen nuclei in the fluorine-containing material are established. The relaxation spectrum fingerprint data includes the component content and transverse relaxation time of the fluorine-containing material; the transverse relaxation time data includes the component ratio and kinetic distribution of the fluorine-containing material.

2. The method according to claim 1, wherein, The coupled nuclear magnetic resonance signal of the fluorine nucleus and the hydrogen nucleus is the coupling of the nuclear magnetic resonance signal of the fluorine nucleus and the nuclear magnetic resonance signal of the hydrogen nucleus; The coupled nuclear magnetic resonance signal of the fluorine nucleus and the hydrogen nucleus is represented as: δ=δ H +δ F ; δ represents the chemical shift of the coupling signal. The δ H The chemical shift of the hydrogen nucleus in the fluorine-containing material. The δ F This represents the chemical shift of the fluorine nuclei in the fluorine-containing material.

3. The method according to claim 1, wherein, Based on the structural characteristics of the fluorine-containing material, the echo peak data is processed to obtain the relaxation spectrum fingerprint data of the fluorine-containing material, including: Based on the structural characteristics of the fluorine-containing material, the data processing method for the echo peak point data is determined and the data processing is performed to obtain the relaxation spectrum fingerprint data of the fluorine-containing material. The structural characteristics of the fluorine-containing material are a semi-crystalline polymer or a cross-linked polymer, and the data processing method is a two-component fitting or a one-component fitting. The relaxation spectrum fingerprint data of the obtained fluorine-containing material is transformed to obtain the transverse relaxation time data of the fluorine-containing material, including: The relaxation spectrum fingerprint data was transformed using the inverse Laplace transform to obtain the transverse relaxation time data of the fluorine-containing material.

4. The method according to claim 3, wherein: When the fluorinated material has the structural characteristics of a semi-crystalline polymer, a two-component fitting method is used to process the echo peak data to obtain the relaxation spectrum fingerprint data of the fluorinated material. The two components include a rigid phase component and a flexible phase component. The relaxation spectrum fingerprint data includes the component content of the rigid phase, the component content of the flexible phase, the transverse relaxation time of the rigid phase, and the transverse relaxation time of the flexible phase of the fluorinated material. When the structural feature of the fluorinated material is a cross-linked polymer, the echo peak data is processed using a single-component fitting method to obtain the relaxation spectrum fingerprint data of the fluorinated material. The single component is a flexible phase component, and the relaxation spectrum fingerprint data includes the component content of the flexible phase of the fluorinated material and the transverse relaxation time of the flexible phase.

5. The method according to claim 4, wherein: The two-component fitting method is expressed as follows: The single-component fitting method is expressed as follows: The acquisition time of the coupled nuclear magnetic resonance signal; The fluorine-containing material was collected at a time when The intensity of the coupled nuclear magnetic resonance signal at any given time; For the fluorine-containing material in Initial coupled nuclear magnetic resonance signal intensity when =0; The content of the rigid phase component in the fluorine-containing material; The content of the flexible phase component in the fluorine-containing material; The transverse relaxation time of the rigid phase of the fluorine-containing material; The transverse relaxation time of the flexible phase of the fluorine-containing material; The structure factor of the rigid phase of the fluorine-containing material; is the structure factor of the flexible phase of the fluorine-containing material.

6. The method according to claim 3, wherein, When the fluorinated material has the structural characteristics of a semi-crystalline polymer, the transverse relaxation time data includes: the component ratio of the rigid phase, the component ratio of the flexible phase, the kinetic distribution of the rigid phase, the kinetic distribution of the flexible phase, the kinetic characteristic relaxation time of the rigid phase component, and the kinetic characteristic relaxation time of the flexible phase component. When the structural feature of the fluorinated material is a cross-linked polymer, the transverse relaxation time data includes: the component ratio of the flexible phase of the fluorinated material, the kinetic distribution of the flexible phase, and the relaxation time of the kinetic characteristics of the flexible phase components; Wherein, the dynamic distribution is the range of time required for the component's motion state to change.

7. The nuclear magnetic resonance analysis method according to claim 1, wherein, The fluorinated materials under different operating conditions include: fluorinated materials from different batches; and / or fluorinated materials at different service stages.

8. A nuclear magnetic resonance analysis method for the chemical composition and condensed-state structure of fluorine-containing materials, comprising: The fluorine-containing material to be tested is placed in a single-sided nuclear magnetic resonance spectrometer. Under a single-sided non-uniform magnetic field environment, the parameters of the spin echo pulse sequence are preset. The spin echo pulse sequence is used to excite the fluorine nuclei and hydrogen nuclei in the fluorine-containing material. The coupled nuclear magnetic resonance signals of the fluorine nuclei and hydrogen nuclei in the fluorine-containing material to be tested are obtained simultaneously through a single radio frequency signal. Based on the preset parameters of the spin echo pulse sequence, the echo peak point data are determined from the coupled nuclear magnetic resonance signal; Based on the structural characteristics of the fluorine-containing material to be tested, the echo peak point data is processed to obtain the relaxation spectrum fingerprint data of the fluorine-containing material to be tested. The relaxation spectrum fingerprint data of the fluorine-containing material to be tested is transformed to obtain the transverse relaxation time data of the fluorine-containing material to be tested. The relaxation spectrum fingerprint data and transverse relaxation time data of the coupling of fluorine nuclei and hydrogen nuclei in the fluorine-containing material to be tested are compared with the relaxation spectrum fingerprint database and transverse relaxation time database of the coupling of fluorine nuclei and hydrogen nuclei in fluorine-containing materials under different operating conditions to determine the quality of the fluorine-containing material to be tested or to analyze the chemical composition and condensed state structure of the fluorine-containing material to be tested.

9. The nuclear magnetic resonance analysis method according to claim 8, further comprising: Material characterization tests were performed on the fluorine-containing materials under different working conditions, and the test results were obtained. Based on the test results, the data in the relaxation spectrum fingerprint database and the transverse relaxation time database of the coupling of fluorine and hydrogen nuclei were graded. The grades include: the service stage grade, quality grade, and failure grade of the fluorine-containing material.

10. An application of the nuclear magnetic resonance analysis method according to any one of claims 8 to 9 in the performance testing of fluorine-containing materials.

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