In-situ detection instrument for chemiluminescence in polymer material reaction process

Abstract

Polymer material reaction process chemiluminescence in-situ detection instrument belongs to the cross field of analytical instrument technology and polymer material reaction process behavior characterization. The detection system is an integrated in-situ detection instrument composed of an in-situ reaction cell, a three-path gas unit, a temperature control unit, a light signal detection unit, and a control and analysis unit. The polymer material is placed in the in-situ reaction cell, the reaction atmosphere gas path and flow rate are adjusted, the temperature program is controlled by the temperature control unit, the controllable in-situ reaction of the polymer is realized, and the chemiluminescence signal in the reaction process is recorded in real time by the light signal detection unit, the in-situ detection of the polymer material reaction process is realized, and the detection system has the characteristics of high sensitivity and good stability, which provides an important monitoring method and means for polymer material formula screening, quality management, degradation control, life control, and regeneration and recycling.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of analytical instrument technology and polymer material characterization. Specifically, it relates to the development of a highly sensitive, chemiluminescence in-situ detection instrument for polymer reaction behavior. By tracking the weak chemiluminescence signals accompanying the polymer reaction process, it achieves in-situ monitoring of the polymer material reaction process, providing important methods and means for polymer material formulation screening, quality management, degradation control, and lifetime control. Background Technology

[0002] Polymers are indispensable basic materials for building modern industrial systems and occupy an important position. However, a large number of polymer products are not effectively managed after their service life ends, leading to increasingly prominent problems of resource waste and environmental impact. Faced with the dual pressures of resource consumption and environmental pollution, polymer life cycle management has become a key path to achieve the green and low-carbon transformation of the plastics industry. Therefore, real-time and accurate monitoring of quality control during the production stage, aging behavior during the service stage, and performance recovery assessment during the recycling stage are crucial prerequisites for ensuring the safe use and efficient recycling of polymers throughout their life cycle.

[0003] Effective management of the polymer lifecycle relies on understanding its dynamic evolution. The polymer lifecycle originates from free radical chain reactions. Through multiple complex chemical processes such as chain initiation, chain elongation, chain branching, and chain termination, the polymer chain generates various types of free radicals. These highly reactive free radicals accumulate in large quantities during the reaction. The types of free radicals and their reaction processes influence the polymer reaction pathways and products, ultimately leading to structural changes and diversified properties. Therefore, real-time monitoring of chain reactions during the polymer lifecycle is both a key focus and a challenge in plastic lifecycle management.

[0004] Traditional methods for detecting free radicals are limited by their high reactivity and short lifespan, making it impossible to achieve highly sensitive, in-situ, and accurate detection of free radicals generated during polymer reactions. The termination of free radicals during polymer reactions produces excited-state products. These excited-state products emit light signals when returning to the ground state, exhibiting chemiluminescence. By recording the chemiluminescence kinetics or characteristic spectra of free radical termination during the reaction, in-situ detection of the polymer reaction process can be achieved. Therefore, chemiluminescence methods demonstrate unique application potential, offering advantages such as high sensitivity, fast response, no need for a light source, and low background signal. However, current commercially available chemiluminescence analyzers primarily target liquid-phase systems or cryogenic conditions. Instruments for in-situ chemiluminescence detection of plastic reaction processes remain scarce, which has become a technical bottleneck restricting highly sensitive, accurate, and real-time monitoring of polymer reaction processes.

[0005] In this invention, a chemiluminescence in-situ detection instrument integrating an in-situ reaction cell, a three-channel gas unit, a temperature control unit, a light signal detection unit, and a control and analysis unit was developed to achieve real-time monitoring of the luminescence behavior of polymer reaction processes. Summary of the Invention

[0006] Polymer reactions involve various free radical reactions, with free radicals terminating to generate excited-state luminescent substances, which then emit optical signals as they return to their ground state. Chemiluminescence instruments can be used to monitor the generation of free radicals during polymer reactions in real time, thereby enabling effective lifecycle management of polymers. Therefore, this invention develops an integrated instrument for in-situ detection of the luminescence behavior during polymer material reactions. It mainly includes an in-situ reaction cell, a three-channel gas unit, a temperature control unit, a light signal detection unit, and a control and analysis unit. The main technical solutions are as follows:

[0007] A chemiluminescence in-situ detection instrument for polymer material reaction processes, comprising an in-situ reaction cell, a three-channel gas unit, a temperature control unit, a light signal detection unit, and a control and analysis unit;

[0008] The main body shell (4) of the in-situ reaction cell (12) is a stainless steel rectangular shell structure. The upper surface of the main body shell (4) is provided with mounting holes and is connected to the bottom of the photomultiplier tube (PMT) detector. The main body shell (4) is provided with a reaction cavity inside, and the pull-out sample injection device is located in the reaction cavity. The pull-out sample injection device includes a sample slot (5), a pull rod head (8), and a pull guide rod. The left and right sides of the main body shell (4) are respectively provided with grooves (4-2) along the length of the main body of the reaction cell. The grooves (4-2) are independent of the reaction cavity. The main body shell (4) is provided with a central port (4-1) and a side port (4-3) at the end. The central port (4-1) is connected to the reaction cavity, so that the sample slot (5) can enter and exit from the central port (4-1). The side ports (4-3) are two respectively connected to the grooves (4-1). 2) Connecting; The pull-out guide rod includes a first pull-out guide rod (9-1) and a second pull-out guide rod (9-2). One end of the first pull-out guide rod (9-1) is fixedly connected to the sample tank (5), and the other end of one end of the first pull-out guide rod (9-1) is fixed together with the pull-out rod head (8). The first pull-out guide rod (9-1) passes through the central port (4-1). One end of the second pull-out guide rod (9-2) is provided with an anti-slip block, and the other end is fixed together with the pull-out rod head (8). The second pull-out guide rod (9-2) passes through the side port (4-3). The second pull-out guide rod (9-2) and the anti-slip block are located in the groove (4-2) to prevent the second pull-out guide rod (9-2) from falling out of the groove (4-2). The groove (4-2) plays a guiding role. The front end and the end of the reaction cavity inside the outer shell (4) of the reaction tank are respectively provided with an inlet connector (1) and an outlet connector (6) for the reaction atmosphere gas.

[0009] The sample cell (5) is equipped with a heating ceramic plate and a thermocouple (7) at the bottom. The wires of the heating ceramic plate and the thermocouple (7) can be introduced from the first pull-out guide rod (9-1) and led out from the second pull-out guide rod (9-2).

[0010] The upper part of the main shell (4) of the reaction tank has an internal thread for the corresponding mounting hole. The mounting hole is equipped with a light window cover assembly (2) with a spiral quick-release structure. The light window cover assembly (2) includes a stainless steel outer ring with a central hole. The stainless steel outer ring has an external thread that can be installed together with the internal thread of the mounting hole. Replaceable fully transparent windows for various light emission wavelengths are installed in the central hole of the stainless steel outer ring.

[0011] Furthermore, the length of the first pull guide rod (9-1) is shorter than the length of the second pull guide rod (9-2); by dragging the pull rod head (8) to pull the first pull guide rod (9-1) to slide, the sample slot (5) of the pull-type sample injection device can move smoothly in and out of the reaction cavity synchronously with the pull rod head (8), realizing the filling and taking out of the polymer sample to be tested. The second pull guide rod (9-2) ensures that the pull-type sample injection device cannot detach from the outer shell (4) of the reaction cell.

[0012] Furthermore, the sample slot is equipped with sample dishes of different sizes, which can accommodate polymer samples in various forms such as powder, flakes, and granules.

[0013] Furthermore, an O-ring (3) is provided between the light window cover assembly (2) and the mounting hole, and after the cover is closed, a sealed cavity is formed inside the reaction tank for polymer reaction.

[0014] Furthermore, the fully transparent window is made of high-transmittance quartz material, and / or further equipped with a bandpass filter that allows light of different wavelengths within the range of 300 ~ 650 nm to pass through; an O-ring is provided between the stainless steel outer ring of the window and the window to ensure the sealing of the reaction cavity after installation.

[0015] Furthermore, a sealing ring is provided between the pull rod head (8) and the edge of the center port (4-1) to achieve sealing of the pull-type sample injection device after it is pushed into the reaction cavity; at the same time, after sealing, the sample slot (5) and the light window cover assembly (2) in the mounting hole are in the same vertical position.

[0016] The outer shell (18) of the chemiluminescence in-situ detection instrument is a stainless steel cuboid structure with a gray protective coating on the surface. Two windows are opened on the side of the outer shell (18). The upper one is an electronic window connected to the computer to display the real-time status during the test. The lower one is used to manually pull out the sample to place it in the sample slot of the in-situ reaction cell (12) or to remove it.

[0017] An in-situ reaction tank support (13) is installed below the in-situ reaction tank (12) to fix and support the in-situ reaction tank (12); the gas inlet connector (1) of the in-situ reaction tank (12) is connected to the three-way manifold (15) through a gas pipeline via a mass flow controller, and the gas outlet connector (6) of the in-situ reaction tank (12) is connected to the exhaust gas pipeline to realize the switching or mixing of the three reaction atmosphere gases; the heating ceramic plate and thermocouple (7) embedded in the sample tank (5) in the in-situ reaction tank (12) are connected to the distributed control system through wires. The system is connected to the DCS (14) to realize the controllable heating and precise temperature measurement of the polymer sample placed in the sample tank (5) in the in-situ reaction cell (12); the light window cover assembly (2) of the in-situ reaction cell (12) and the upper photomultiplier tube PMT detector (11) are in the same vertical position and are connected to the photomultiplier tube PMT detector (11). The chemiluminescence signal of the polymer reaction to generate intermediates can be transmitted to the photomultiplier tube PMT detector (11) through the light window of the reaction cell to realize real-time monitoring of the reaction process;

[0018] The three-channel gas unit includes a three-channel manifold (15) and a mass flow controller. The three-channel manifold (15) is connected to the external reaction atmosphere gas through a gas pipeline channel opened on the chemiluminescence instrument housing (18). The default reaction atmosphere gas is air, which can be expanded to nitrogen, argon, or a mixed gas. After the reaction, the atmosphere gas is discharged through the exhaust gas pipeline. The mass flow controller is used for quantitative introduction of the reaction atmosphere gas. The gas flow rate control range is 25 ~ 300 mL / min, and the control error is ≤ ± 15 mL / min.

[0019] The temperature control unit includes a heating ceramic plate and a thermocouple (7) and a distributed control system (DCS) (14). The distributed control system (DCS) (14) supports multi-segment temperature programmed control, with a temperature control range from room temperature to 300 ℃ and a temperature control accuracy of ≤ ±1℃.

[0020] The optical signal detection unit includes a photomultiplier tube (PMT) detector (11) and an analog-to-digital converter (ADC) (16). The PMT detector (11) can acquire optical signals in the wavelength range of 300 ~ 650 nm, and can detect 10 -13 A weak light source can provide a count rate of 10,000 to 20,000 per second.

[0021] Furthermore, the photomultiplier tube (PMT) detector (11) is connected to the analog-to-digital converter (ADC) (16) via a wire, converting the light signals collected at sampling intervals into digital signals to achieve high-sensitivity detection. The counting analysis range is 0~2. 16 RLU.

[0022] Furthermore, the analog-to-digital converter (ADC) (16) is located above the bracket (17), and the distributed control system (DSC) (14) and the three-way bus (15) are located below the bracket.

[0023] Furthermore, a light window shutter is provided between the light window cover assembly (2) of the in-situ reaction cell (12) and the photomultiplier tube PMT detector (11) to protect the photomultiplier tube PMT detector (11).

[0024] The control and analysis unit connects to an external computer via a communication interface to control the test conditions and analyze the luminescence signal data. The chemiluminescence analyzer housing (18) is equipped with a USB 2.0 communication interface, internally connected to an analog-to-digital converter (ADC) (16) and a distributed control system (DSC) (14), and externally connected to a computer. Test conditions can be set via computer software. The test conditions include the selectable reaction atmosphere gas and its flow rate; temperature control program settings, including multiple temperature programs such as initial temperature, heating rate, and target temperature; and light signal acquisition parameters, including negative high voltage: -(0~1000)V; sampling interval: 0.2~100000 ms; running time: 0~86400 s; and background subtraction. The test conditions are displayed synchronously on the computer software interface for real-time monitoring of the test process.

[0025] Furthermore, the computer is equipped with data processing software that inputs the collected light signals and displays them as luminescence dynamics curves in real time. It supports various data visualization formats, including newly collected data, local data (already collected data), and database data (data from the internet or newly imported data), and displays the collection time and total count in real time. Through functions such as coordinate picking, multi-peak segmentation, area integration, and path fitting, the test data is analyzed to obtain luminescence parameters such as peak emergence time, luminescence intensity, luminescence peak area, and free radical types. It also supports generating data in various formats such as EXCEL and TXT from the luminescence parameters and luminescence dynamics and saving them locally or in a database.

[0026] Furthermore, the database supports the retrieval and access of information such as task name, molecular formula and string characterization SMILES code, test conditions, luminescence kinetic curve and luminescence parameters.

[0027] This invention features high sensitivity and good stability, providing important monitoring methods and means for polymer material formulation screening, quality management, degradation control, lifetime control and recycling, and basic research. Attached Figure Description

[0028] Figure 1: A three-dimensional view of the overall structure of the chemiluminescence in-situ detection instrument for polymer material reaction process in this invention;

[0029] Figure 2 : Schematic diagram of the outer casing of the chemiluminescence in-situ detection instrument in this invention;

[0030] Figure 3 : A schematic diagram of the overall three-dimensional structure of the in-situ reaction tank in this invention;

[0031] Figure 4 : A three-dimensional structural diagram of the in-situ reaction tank reaction chamber in this invention;

[0032] Figure 5 : Schematic diagram of the pull-out sample introduction device in this invention;

[0033] Figure 6 : Schematic diagram of the structure of the in-situ reaction tank light window cover assembly in this invention;

[0034] Figure 7 : Schematic diagram of the photomultiplier tube (PMT) detector structure in this invention;

[0035] Figure 8 : A three-dimensional view of the overall structure of the chemiluminescence in-situ detection instrument for polymer material reaction process in this invention;

[0036] Figure 9 Example: Visualization interface and chemiluminescence map of ultra-high density polyethylene (UHDPE) sample test.

[0037] Figure 1 In the middle: 11. Photomultiplier tube (PMT) detector, 12. In-situ reaction cell, 13. In-situ reaction cell support, 14. DSC, 15. Busbar, 16. ADC, 17. Support, 18. Casing;

[0038] Figure 3 In the middle: 1. Reaction atmosphere gas inlet connector, 2. Light window cover assembly, 3. O-ring seal, 4. Reaction cell main body shell, 4-1. Center port, 4-2. Groove, 4-3. Side port, 5. Sample cell, 6. Reaction atmosphere gas outlet connector, 7. Heating ceramic plate and thermocouple, 8. Push-pull rod head, 9-1. First push-pull guide rod, 9-2. Second push-pull guide rod. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1:

[0041] To address the technical problems in the background art, a chemiluminescence detection system for polymer material reaction processes is provided as follows:

[0042] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0043] This technical solution provides a chemiluminescence in-situ detection instrument for polymer material reaction processes, used for real-time online monitoring of free radical reactions during polymer material reactions. This chemiluminescence in-situ detection instrument mainly consists of five core units: an in-situ reaction cell, a three-channel gas unit, a temperature control unit, a light signal detection unit, and a control and analysis unit. Figure 1 As shown. The chemiluminescence monitoring instrument for polymer material reaction processes has a stainless steel cuboid casing with a gray protective coating on the surface, such as... Figure 2 As shown. The chemiluminescence in-situ detection instrument for polymer material reaction process adopts an integrated design. The in-situ reaction cell, three-channel gas unit, temperature control unit, and optical signal detection unit are all integrated inside the shell. The in-situ reaction cell (12) provides a reaction site for the polymer, and the chemiluminescence signal generated can be transmitted to the optical signal detection unit in real time through the optical window to achieve in-situ and continuous acquisition. The three-channel gas unit and temperature control unit provide the required reaction atmosphere and temperature conditions for the polymer material reaction. The control and analysis unit is assembled in an external computer for gas parameter regulation, temperature programmable control, and data analysis and processing. This chemiluminescence in-situ detection instrument for polymer material reaction process is used for dynamic monitoring of the luminescence behavior of polymer material reaction process, sensitively capturing the chemiluminescence signal in the polymer reaction process, reflecting the microstructural changes such as chain breakage and cross-linking that occur inside the material, and thus providing important experimental data and technical support for the preparation and modification of polymer materials, stability evaluation, degradation mechanism elucidation, and high-value utilization.

[0044] The main shell (4) of the in-situ reaction tank (12) is an integral stainless steel cuboid shell structure, such as... Figure 3 As shown. The upper surface of the main body shell (4) is provided with mounting holes, which are connected and installed below the photomultiplier tube PMT detector; the reaction chamber main body shell (4) is provided with a reaction cavity, and the pull-out sample injection device is located in the reaction cavity; the pull-out sample injection device includes a sample slot (5), a pull rod head (8), and a pull guide rod; the left and right sides of the reaction chamber main body shell (4) are respectively provided with grooves (4-2) along the length direction of the main body of the reaction chamber, and the grooves (4-2) are independent of the reaction cavity; the end of the reaction chamber main body shell (4) is provided with a central port (4-1) and a side port (4-3), as shown. Figure 4As shown, the central port (4-1) is connected to the reaction cavity, allowing the sample tank (5) to enter and exit from the central port (4-1). The side ports (4-3) are two in number, each connected to a groove (4-2). The pull-out guide rod includes a first pull-out guide rod (9-1) and a second pull-out guide rod (9-2). One end of the first pull-out guide rod (9-1) is fixedly connected to the sample tank (5), and the other end of one end of the first pull-out guide rod (9-1) is fixed to the pull-out rod head (8). The first pull-out guide rod (9-1) passes through the central port (4-1). 4-1); One end of the second pull guide rod (9-2) is provided with an anti-slip block, and the other end is fixed together with the pull rod head (8). The second pull guide rod (9-2) passes through the side port (4-3). The second pull guide rod (9-2) and the anti-slip block are located in the groove (4-2) to prevent the second pull guide rod (9-2) from falling out of the groove (4-2). The groove (4-2) plays a guiding role. The front end and the end of the reaction cavity inside the main body shell (4) are respectively provided with an inlet connector (1) and an outlet connector (6) for the reaction atmosphere gas.

[0045] The sample tank (5) of the reaction cell is equipped with a heating ceramic plate and a thermocouple (7) at the bottom, such as Figure 5 As shown, the wires of the hot ceramic sheet and thermocouple (7) can be introduced from the first pull guide rod (9-1) and led out from the second pull guide rod (9-2), and externally connected to the distributed control system DCS (14) for controllable heating and precise temperature measurement of polymer samples placed in the sample slot (5) of the in-situ reaction pool (12).

[0046] The upper part of the outer shell of the reaction tank (4) has a corresponding mounting hole with an internal thread. The mounting hole is equipped with a reaction tank light window cover assembly (2), which adopts a spiral quick-release structure. The reaction tank light window cover assembly (2) includes a stainless steel outer ring with a central hole, such as Figure 6 As shown, the stainless steel outer ring has external threads that can be installed together with the internal threads of the mounting hole. The center hole of the stainless steel outer ring is used to install replaceable fully transparent windows for various emission wavelengths. The light windows are made of high-transmittance quartz material and are equipped with bandpass filters that allow light of different wavelengths in the range of 300 ~ 650 nm to pass through. An O-ring is provided between the stainless steel outer ring and the light windows to ensure the sealing of the reaction cavity. During the reaction, the chemiluminescence signal can be recorded by the photomultiplier tube (PMT) detector through the light windows / bandpass filters.

[0047] The length of the first pull guide rod (9-1) is shorter than the length of the second pull guide rod (9-2); by dragging the pull rod head (8) to pull the first pull guide rod (9-1) to slide, the sample slot (5) of the pull-type sample feeding device can move smoothly in and out of the reaction cavity synchronously with the pull rod head (8), so as to realize the filling and taking out of the polymer sample to be tested.

[0048] A sealing ring is provided between the pull rod head (8) and the edge of the center port (4-1) to achieve sealing after the pull-type sample injection device is pushed into the reaction cavity; at the same time, after sealing, the sample slot (5) is aligned with the light window of the mounting hole.

[0049] The front of the chemiluminescence in-situ detection instrument for polymer material reaction process has two windows. The upper electronic window is used to display the running status of the test stage in real time, and the lower window is equipped with a pull-out sample reaction in-situ cell (2), which is used to manually pull out the sample to place in the sample slot of the in-situ reaction cell (12) or to take it out. Multiple interfaces are provided at the rear of the casing, which are used to connect the USB interface of the external computer, the gas inlet pipe, the gas outlet pipe and the power interface respectively. Multiple fixing bolts are provided on the bottom plate at the bottom of the casing for fixing and limiting the internal components.

[0050] The in-situ reaction cell (12) has a rectangular structure and is fixed above the in-situ reaction cell support (13); a Japanese Hamamatsu CR105 photomultiplier tube PMT detector (11) is installed above the in-situ reaction cell (12), such as Figure 7 As shown, it is a cylindrical structure. The photomultiplier tube PMT detector (11) and the light window cover assembly above the in-situ reaction cell (12) are in the same vertical position and are connected to each other. A light window shutter is set in the middle (all photomultiplier tube PMT detectors are equipped with a light window shutter. The light window shutter is a mature technology in the field of photomultiplier tube PMT detectors and is also a supporting technology for the commercialization of photomultiplier tube PMT detectors) to achieve strong light protection for the photomultiplier tube PMT detector (11). The chemiluminescence signal generated during the polymer reaction inside the in-situ reaction cell (12) can be transmitted to the photomultiplier tube PMT (11) through the light window and recorded in real time.

[0051] The photomultiplier tube (PMT) detector (11) is equipped with a circular stainless steel metal shutter. At the start of detection, the shutter rotates around a side axis via mechanical linkage, opening the shutter and allowing the PMT detector to sense the sample light signal and detect the sample. At the end of detection, the shutter closes, ensuring that the PMT detector can move the pull-out sample introduction device without closing. Simultaneously, an optical sensor is provided. When the light intensity exceeds the measurement range, the optical sensor sends a signal to the host computer to close the shutter, preventing damage to the PMT detector from strong light.

[0052] This technical solution is applicable to the in-situ detection of polymer reaction processes using chemiluminescence. In specific implementation, under normal temperature conditions, the in-situ reaction cell (12) is first extracted, a certain amount of polymer sample is loaded into a sample dish, the sample dish is fixed in the sample slot (5), and then sent into the reaction chamber inside the in-situ reaction cell (12). Figure 8As shown. Next, by pre-setting the gas passage and flow rate parameters through an external computer, the reaction atmosphere gas is stably introduced into the internal reaction chamber of the in-situ reaction tank (12) through the mass flow controller and the three-way manifold (15), and the reaction atmosphere is turned on for a period of time. Subsequently, the heating rate and target temperature and other multi-segment temperature programs are set by the distributed control system (DCS) controlled by the external computer to provide a stable and accurate temperature control environment for the reaction system. During this process, the negative high pressure, sampling interval, running time, background subtraction and other light signal detection parameters are set, the chemiluminescence detection program is started, and the system luminescence signal is collected online in real time to obtain the luminescence kinetics of the polymer in the reaction process. The recorded luminescence kinetics are displayed on the software interface and analyzed to obtain the luminescence kinetic parameters. The results are saved locally or in the database.

[0053] In this example, UHDPE film was used as the test material and assembled in the sample cell of the in-situ reaction cell (12). The reaction process of the polymer material was detected using a chemiluminescence in-situ detection instrument. The specific steps are as follows:

[0054] To prepare a UHDPE film sample with a thickness of 0.25 mm, firstly, under normal temperature conditions, a sample of the UHDPE film to be tested with an area of ​​0.5 cm × 0.5 cm was placed in a sample dish and weighed using an electronic balance. Then, it was placed in the sample slot of the reaction cell and pushed into the reaction chamber inside the in-situ reaction cell (12). Next, air at a flow rate of 100 mL / min was introduced as the reaction atmosphere gas, and the reaction atmosphere gas was turned on for a period of time. Then, the temperature program was set: the temperature was raised to the reaction temperature of 280 °C at a heating rate of 10 °C / s, and the temperature was maintained at 280 °C. Finally, the optical signal detection parameters were set as follows: negative high voltage of -800V, sampling interval of 1 s, running time of 3600 s, background subtraction, and the chemiluminescence detection program was started simultaneously. The shutter of the optical window was opened, and the photomultiplier tube (PMT) detector received the optical signal of the UHDPE sample under the set conditions. The analog-to-digital converter (ADC) converted the optical signal into a digital signal, obtaining the luminescence dynamics curve of the UHDPE sample. The recorded luminescence dynamics curve was simultaneously displayed in the software interface, such as... Figure 9 As shown. The recorded luminescence kinetic curves were analyzed using software. The peak time of the UHDPE sample was found to be 831 s and the luminescence intensity was 12090 au by coordinate picking. The data of the UHDPE sample were obtained by path fitting. The free radical type was found to be alkoxy radical RO• (data analysis can be performed according to different requirements or data processing, which is not limited). The sample information, test parameters and luminescence kinetic curves were saved in the database.

Claims

1. A chemiluminescence in-situ detection instrument for polymer material reaction processes, characterized in that, It includes an in-situ reaction tank, a three-channel gas unit, a temperature control unit, a light signal detection unit, and a control and analysis unit; The main body shell (4) of the in-situ reaction cell (12) is a stainless steel rectangular shell structure. The upper surface of the main body shell (4) is provided with mounting holes and is connected to the bottom of the photomultiplier tube (PMT) detector. The main body shell (4) is provided with a reaction cavity inside, and the pull-out sample injection device is located in the reaction cavity. The pull-out sample injection device includes a sample slot (5), a pull rod head (8), and a pull guide rod. The left and right sides of the main body shell (4) are respectively provided with grooves (4-2) along the length of the main body of the reaction cell. The grooves (4-2) are independent of the reaction cavity. The main body shell (4) is provided with a central port (4-1) and a side port (4-3) at the end. The central port (4-1) is connected to the reaction cavity, so that the sample slot (5) can enter and exit from the central port (4-1). The side ports (4-3) are two respectively connected to the grooves (4-1). 2) Connecting; The pull-out guide rod includes a first pull-out guide rod (9-1) and a second pull-out guide rod (9-2). One end of the first pull-out guide rod (9-1) is fixedly connected to the sample tank (5), and the other end of one end of the first pull-out guide rod (9-1) is fixed together with the pull-out rod head (8). The first pull-out guide rod (9-1) passes through the central port (4-1). One end of the second pull-out guide rod (9-2) is provided with an anti-slip block, and the other end is fixed together with the pull-out rod head (8). The second pull-out guide rod (9-2) passes through the side port (4-3). The second pull-out guide rod (9-2) and the anti-slip block are located in the groove (4-2) to prevent the second pull-out guide rod (9-2) from falling out of the groove (4-2). The groove (4-2) plays a guiding role. The front end and the end of the reaction cavity inside the outer shell (4) of the reaction tank are respectively provided with an inlet connector (1) and an outlet connector (6) for the reaction atmosphere gas. The sample cell (5) is equipped with a heating ceramic plate and a thermocouple (7) at the bottom. The wires of the heating ceramic plate and the thermocouple (7) can be introduced from the first pull-out guide rod (9-1) and led out from the second pull-out guide rod (9-2). The upper part of the main shell of the reaction tank (4) has an internal thread for the corresponding mounting hole. The mounting hole is equipped with a light window cover assembly (2) with a spiral quick-release structure. The light window cover assembly (2) includes a stainless steel outer ring with a central hole. The stainless steel outer ring has an external thread that can be installed together with the internal thread of the mounting hole. Replaceable fully transparent windows for various light emission wavelengths are installed in the central hole of the stainless steel outer ring. The outer shell (18) of the chemiluminescence in-situ detection instrument is a stainless steel cuboid structure with a gray protective coating on the surface. Two windows are opened on the side of the outer shell (18). The upper one is an electronic window connected to the computer to display the real-time status during the test. The lower one is used to manually pull out the sample to place it in the sample slot of the in-situ reaction cell (12) or to remove it. An in-situ reaction tank support (13) is installed below the in-situ reaction tank (12) to fix and support the in-situ reaction tank (12); the gas inlet connector (1) of the in-situ reaction tank (12) is connected to the three-way manifold (15) through a gas pipeline via a mass flow controller, and the gas outlet connector (6) of the in-situ reaction tank (12) is connected to the exhaust gas pipeline to realize the switching or mixing of the three reaction atmosphere gases; the heating ceramic plate and thermocouple (7) embedded in the sample tank (5) in the in-situ reaction tank (12) are connected to the distributed control system through wires. The system is connected to the DCS (14) to realize the controllable heating and precise temperature measurement of the polymer sample placed in the sample tank (5) in the in-situ reaction cell (12); the light window cover assembly (2) of the in-situ reaction cell (12) and the photomultiplier tube PMT detector (11) are in the same vertical position and connected to the photomultiplier tube PMT detector (11). The chemiluminescence signal of the polymer reaction intermediate can be transmitted to the photomultiplier tube PMT detector (11) through the light window of the reaction cell to realize real-time monitoring of the reaction process.

2. The chemiluminescence in-situ detection instrument for polymer material reaction processes according to claim 1, characterized in that, The three-channel gas unit includes a three-channel manifold (15) and a mass flow controller. The three-channel manifold (15) is connected to the external reaction atmosphere gas through a gas pipeline channel opened on the chemiluminescence instrument housing (18). The default reaction atmosphere gas is air, which can be expanded to nitrogen, argon, or a mixed gas. After the reaction, the atmosphere gas is discharged through the exhaust gas pipeline. The mass flow controller is used for quantitative introduction of the reaction atmosphere gas. The gas flow rate control range is 25 ~ 300 mL / min, and the control error is ≤ ± 15 mL / min.

3. The chemiluminescence in-situ detection instrument for polymer material reaction processes according to claim 1, characterized in that, The temperature control unit includes a heating ceramic plate and a thermocouple (7) and a distributed control system (DCS) (14); the distributed control system (DCS) (14) supports multi-segment temperature programmable control, with a temperature control range from room temperature to 300 ℃ and a temperature control accuracy of ≤ ±1 ℃.

4. The chemiluminescence in-situ detection instrument for polymer material reaction processes according to claim 1, characterized in that, The optical signal detection unit includes a photomultiplier tube (PMT) detector (11) and an analog-to-digital converter (ADC) (16); the photomultiplier tube (PMT) detector (11) can acquire optical signals in the wavelength range of 300 ~ 650 nm, and can provide a count rate of 10,000 ~ 20,000 / s for a weak light source of 10-13 W; The photomultiplier tube (PMT) detector (11) is connected to an analog-to-digital converter (ADC) (16) via wires, converting the light signals collected at sampling intervals into digital signals to achieve high-sensitivity detection. The counting analysis range is 0 ~ 2. 16 RLU.

5. A chemiluminescence in-situ detection instrument for polymer material reaction processes according to claim 1, characterized in that, The analog-to-digital converter (ADC) (16) is located above the bracket (17), and the distributed control system (DSC) (14) and the three-way bus (15) are located below the bracket.

6. A chemiluminescence in-situ detection instrument for polymer material reaction processes according to claim 1, characterized in that, The control and analysis unit is connected to an external computer via a communication interface to control the test conditions and analyze the luminescence signal data. The chemiluminescence instrument housing (18) is equipped with a USB 2.0 communication interface, which is internally connected to the analog-to-digital converter (ADC) (16) and the distributed control system (DSC) (14), and externally connected to a computer. Test conditions can be set through computer software. The test conditions include the selectable reaction atmosphere gas and its flow rate; the temperature control program settings, including multiple temperature programs such as starting temperature, heating rate, and target temperature; and light signal acquisition parameters, including negative high voltage: -(0 ~ 1000)V; sampling interval: 0.2 ~ 100000 ms; running time: 0 ~ 86400 s; and background subtraction. The test conditions are displayed synchronously on the computer software interface for real-time monitoring of the test process.

7. A chemiluminescence in-situ detection instrument for polymer material reaction processes according to claim 1, characterized in that, The computer terminal is equipped with data processing software that inputs the collected light signals and displays them as luminescence dynamics curves in real time. It supports various data visualization formats, including collected data, local data, and database data, and displays the collection time and total count in real time. Through functions such as coordinate picking, multi-peak segmentation, area integration, and path fitting, the test data is analyzed to obtain luminescence parameters such as peak emergence time, luminescence intensity, luminescence peak area, and free radical types. It also supports generating data in various formats such as EXCEL and TXT from the luminescence parameters and luminescence dynamics and saving them locally or in a database. The database supports the retrieval and access of information such as task name, molecular formula and string characterization SMILES code, test conditions, luminescence kinetic curve and luminescence parameters.

8. A chemiluminescence in-situ detection instrument for polymer material reaction processes according to claim 1, characterized in that, The length of the first pull guide rod (9-1) is shorter than the length of the second pull guide rod (9-2). By dragging the pull rod head (8) to pull the first pull guide rod (9-1) to slide, the sample slot (5) of the pull-type sample injection device can move smoothly in and out of the reaction cavity synchronously with the pull rod head (8), so as to realize the filling and taking out of the polymer sample to be tested. The second pull guide rod (9-2) ensures that the pull-type sample injection device cannot be separated from the outer shell (4) of the reaction cell.

9. A chemiluminescence in-situ detection instrument for polymer material reaction processes according to claim 1, characterized in that, The sample slot is equipped with sample dishes of different sizes, which can accommodate polymer samples in various forms such as powder, flakes, and granules. The light window cover assembly (2) is also equipped with an O-ring (3) between it and the mounting hole. After the cover is closed, a sealed cavity is formed inside the reaction tank for polymer reaction. The fully transparent window is made of high-transmittance quartz material, and / or further equipped with a bandpass filter that allows light of different wavelengths within the range of 300 ~ 650 nm to pass through; the outer ring of the stainless steel window and the window itself are provided with O-rings to ensure the sealing of the reaction cavity after installation. A sealing ring is provided between the pull rod head (8) and the edge of the center port (4-1) to achieve sealing after the pull-type sample injection device is pushed into the reaction cavity; at the same time, after sealing, the sample slot (5) and the light window cover assembly (2) in the mounting hole are in the same vertical position.

10. A chemiluminescence in-situ detection instrument for polymer material reaction processes according to claim 1, characterized in that, A shutter is provided between the light window cover assembly (2) of the in-situ reaction cell (12) and the photomultiplier tube PMT detector (11).

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