An in-situ reaction cell adapted for chemiluminescence detection of polymer material reaction processes

Abstract

An in-situ reaction cell adapted for chemiluminescence detection in polymer material reaction processes belongs to the interdisciplinary field of analytical instruments and material aging characterization. This in-situ reaction cell comprises a main body shell, a pull-out sample introduction device, a temperature control system, and a light window cover assembly. The main body of the reaction cell has a reaction cavity and is equipped with inlet and outlet ports to allow for the introduction of various atmospheres. The pull-out sample introduction device includes a sample slot, a pull guide rod, and a pull rod head, enabling stable sample loading and precise positioning. The temperature control system uses a ceramic heating element and a thermocouple working in tandem to achieve precise temperature control. The light window cover assembly adopts a spiral quick-release structure, equipped with a detachable light window and a bandpass filter for easy acquisition of luminescence signals. This invention achieves real-time, in-situ, and highly sensitive monitoring of free radical pathways during polymer reactions, solving the problems of poor adaptability, insufficient accuracy and stability of optical signal acquisition in traditional in-situ reaction cells.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of analytical instrument technology and characterization of luminescence behavior in polymer material reaction processes, and in particular relates to the development of an in-situ reaction cell for a chemiluminescence in-situ detection instrument adapted to polymer reaction behavior. Background Technology

[0002] Plastic materials possess characteristics such as high strength, low density, and light weight. Their low price and easy processability make them widely used in daily life, industrial production, and military defense. However, during service, plastic materials are affected by external factors such as light, heat, and humidity, leading to structural degradation, performance deterioration, and shortened service life. During these reactions, plastics generate various free radicals, which directly influence the degradation pathway and final products of the material. Therefore, real-time monitoring of free radicals generated during the degradation reaction of plastics is crucial for understanding the degradation behavior of plastic materials and controlling their degradation pathways.

[0003] Currently, most methods for detecting free radicals are based on spin paramagnetic resonance spectroscopy. However, this method can only detect specific types of free radicals under the action of a scavenger, and cannot achieve real-time monitoring and quantitative analysis of multiple free radicals, which greatly limits the study of the reaction behavior of plastics. Chemiluminescence detection methods are based on the radiation signals generated by excited-state substances produced by free radical termination to study the reaction behavior of plastics. This detection method has advantages such as fast response speed and the ability to achieve in-situ detection. However, the reaction cells of traditional chemiluminescence detectors are mostly piecemeal custom-assembled, and generally suffer from poor adaptability and insufficient stability. During long-term operation, problems such as material fatigue deformation, flow channel scaling and deposition, and decreased optical interface transmittance are prone to cumulative effects, which will affect the accuracy and stability of optical signal acquisition, leading to sensitivity drift and poor repeatability.

[0004] This invention discloses an in-situ reaction cell adapted for chemiluminescence detection in polymer material reaction processes. The device features an integrated design, is easy to operate, exhibits excellent stability, and is compatible with various reaction samples, including powders, particles, films, and blocks. It boasts strong compatibility and is equipped with multiple independent atmosphere channels to flexibly adapt to various reaction scenarios. Simultaneously, the reaction cell is connected to a high-precision temperature control module, which can accurately maintain the reaction temperature. Furthermore, in conjunction with a high-sensitivity chemiluminescence detector, it can monitor ultra-weak chemiluminescence signals generated during polymer reactions under different atmospheres and temperatures. This design effectively solves the problems of low automation and insufficient environmental control precision in traditional detection methods, providing a reliable and efficient integrated in-situ analysis platform for polymer reaction mechanism research. Summary of the Invention

[0005] Chemiluminescence detection methods can be used to monitor free radicals generated during polymer reactions in real time, thereby enabling the exploration of polymer reaction mechanisms. Therefore, this invention develops an in-situ reaction cell adapted for chemiluminescence detection of polymer reaction behavior. The main body of this in-situ cell is made of stainless steel, and it is equipped with a gas flow system, a pull-out sample introduction device, a temperature control system, and a light window cover assembly. The main technical solutions are as follows:

[0006] An in-situ reaction cell adapted for chemiluminescence detection of polymer material reaction process is characterized in that the main shell (4) of the reaction cell is a stainless steel cuboid shell structure, which can be installed and fixed inside the in-situ chemiluminescence detection instrument for polymer material reaction process.

[0007] The upper surface of the main shell of the reaction tank (4) is provided with mounting holes, which are connected and installed below the photomultiplier tube (PMT) detector;

[0008] The main body shell (4) of the reaction cell has 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) of the reaction cell have grooves (4-2) along the length of the main body of the reaction cell, and the grooves (4-2) are independent of the reaction cavity; the end of the main body shell (4) of the reaction cell has a central port (4-1) and a side port (4-3), 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), and the side ports (4-3) are two in number and are connected to the grooves (4-2) respectively; The guide rod includes a first pull guide rod (9-1) and a second pull guide rod (9-2). One end of the first pull guide rod (9-1) is fixedly connected to the sample groove (5), and the other end of the first pull guide rod (9-1) is fixed together with the pull rod head (8). The first pull guide rod (9-1) passes through the central port (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 dislodging from the groove (4-2).

[0009] The front and rear ends of the reaction chamber inside the outer shell (4) of the reaction tank are respectively provided with an inlet (1) and an outlet (6) for the reaction atmosphere gas.

[0010] The sample tank (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 guide rod (9-1) and led out from the second pull guide rod (9-2) to be connected to the external distributed control system (DCS). The heating program suitable for the target reaction is set so as to realize the controllable heating and accurate temperature measurement of the polymer sample placed in the sample tank (5) of the reaction pool.

[0011] 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.

[0012] 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), 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.

[0013] 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.

[0014] 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.

[0015] Furthermore, the stainless steel outer ring has a central hole through which a fully transparent window is inserted. 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 to 650 nm to pass through.

[0016] Furthermore, the light window cover assembly (2) is in the same vertical position as the upper photomultiplier tube (PMT) detector and is connected to it. The chemiluminescence signal of the polymer reaction to generate intermediates can be transmitted to the photomultiplier tube (PMT) detector through the light window to realize real-time monitoring of the reaction process.

[0017] 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.

[0018] Furthermore, the reaction atmosphere gas is input from the inlet connector (1), flows through the polymer sample inside the reaction chamber cavity, and is discharged from the outlet connector (6).

[0019] This invention enables real-time, in-situ, and highly sensitive monitoring of free radical reactions during polymer reactions, solving the problems of cumbersome operation and low precision of condition control in traditional detection devices, and providing a reliable and efficient analytical platform for polymer reaction mechanism research. Attached Figure Description

[0020] Figure 1 : A schematic diagram of the overall three-dimensional structure of the in-situ reaction tank in this invention;

[0021] Figure 2 Top view of the in-situ reaction tank in this invention;

[0022] Figure 3 : A three-dimensional structural diagram of the in-situ reaction chamber in this invention;

[0023] Figure 4 : Schematic diagram of the in-situ reaction cell pull-out sample introduction device in this invention;

[0024] Figure 5 : Schematic diagram of the structure of the in-situ reaction tank light window cover assembly in this invention;

[0025] Figure 6 Example: Chemiluminescence spectrum obtained from testing linear low-density polyethylene;

[0026] Figure 1 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

[0027] 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.

[0028] Example 1:

[0029] To address the technical problems in the background art, the following in-situ cell adapted for chemiluminescence detection of polymer reactions is provided:

[0030] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0031] This technical solution provides an in-situ cell adapted for chemiluminescence detection of polymer reaction behavior, used for real-time online monitoring of free radical reactions in polymer reaction processes. The reaction cell mainly consists of a main outer shell, a pull-out sample introduction device, a light window cover assembly, a gas flow system, and a temperature control system. Figure 1 As shown, this device is compatible with in-situ chemiluminescence detection instruments for polymer material reactions. The main body of the reaction cell is made of high-temperature and corrosion-resistant stainless steel, with an internal cylindrical reaction cavity to provide space for the polymer material reaction. A pull-out sample introduction device enables sample positioning and introduction, ensuring a stable and reliable detection process. A gas flow system and a temperature control system provide the necessary atmosphere and temperature conditions for the polymer material reaction. The light window cover assembly transmits the weak chemiluminescence signal generated during the reaction to the chemiluminescence detector through a high-transmittance light window. This in-situ reaction cell provides a carrier for the accelerated reaction of polymer materials. The generated chemiluminescence signal can be acquired in-situ and continuously by the top-mounted chemiluminescence detector, thereby sensitively monitoring the reaction kinetics of the polymer during the accelerated reaction process, reflecting the evolution of the microstructure of the internal chain segments, and providing key information for revealing degradation mechanisms, assessing material stability, and guiding polymer development and modification.

[0032] The main shell of the reaction cell (4) is a stainless steel cuboid shell structure. The main shell of the reaction cell (4) has an installation hole, which can be installed and fixed inside the chemiluminescence instrument, and ensure that the reaction cell and the external photomultiplier tube PMT detector are in the same vertical position and connected to the photomultiplier tube PMT detector.

[0033] The main body shell (4) of the reaction cell has a cylindrical reaction cavity inside, which can accommodate a pull-out sample injection device. The pull-out sample injection device includes a sample slot (5), a pull rod head (8), and a pull guide rod. The main body shell (4) of the reaction cell has grooves (4-2) on the left and right sides 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) of the reaction cell has 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 in number and are connected to the grooves (4-2) respectively. The pull guide rod includes a first pull guide rod (9-1) and a second pull guide rod (9-2). One end of the first pull guide rod (9-1) is fixedly connected to the sample slot (5). The first pull guide rod (9-1) has a first pull guide rod (9-1) and a second pull guide rod (9-2). The other end is fixed to the pull rod head (8), and the first pull guide rod (9-1) passes through the central port (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 to the pull rod head (8), and 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 leaving the groove (4-2); 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 be moved synchronously with the pull rod head (8) and smoothly enter and exit the reaction cavity. 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.

[0034] Different forms of polymer samples to be tested, such as granules, films, or powders, are first placed in a sample dish and then placed in the sample slot (5). A sealing ring is provided between the pull rod head (8) and the edge of the central 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.

[0035] The front and rear ends of the reaction cavity inside the outer shell (4) of the reaction cell are respectively provided with an inlet connector (1) and an outlet connector (6) for the reaction atmosphere gas. The reaction gas pipeline is connected to the reaction cavity inside the reaction cell through the inlet connector (1) and the outlet connector (6) to realize the flow of the reaction atmosphere gas inside the reaction cavity. When the sample to be tested is pushed into the reaction cavity inside the reaction cell and aligned with the light window of the reaction cell ( Figure 2 The reaction tank body forms a closed reaction cavity. The reaction atmosphere gas is input from the inlet connector (1), flows through the polymer sample in the reaction tank body, and is discharged from the outlet connector (6). Figure 3 ).

[0036] The sample holder (5) is equipped with a heating ceramic plate and a thermocouple (7) at the bottom, such as Figure 4 As shown, the wires of the heating ceramic plate and thermocouple (7) can be introduced from the first pull-out guide rod (9-1) and connected to the external distributed control system (DCS) to realize controllable heating and accurate temperature measurement of polymer reaction temperature.

[0037] The upper mounting hole of the main shell of the reaction tank (4) is provided with an internal thread. Through a spiral quick-release structure, it is screwed onto the light window cover assembly (2). 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. An O-ring (3) is provided between the threads on the upper surface of the light window cover assembly (2) and the main shell of the reaction tank (4). After being covered, a sealed cavity is formed inside the reaction tank for in-situ reaction of the polymer. The central hole of the stainless steel outer ring is used to install the light window. The light window is made of high-transmittance quartz material and is a fully transparent window / bandpass filter that allows 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 window. Figure 5 As shown, the chemiluminescence signal during the reaction can be recorded by the photomultiplier tube (PMT) detector through a fully transparent window / bandpass filter.

[0038] This technical solution is suitable for in-situ monitoring of polymer reaction processes using chemiluminescence. In specific implementation, first assemble the reaction cell light window cover assembly (2), insert a suitable light window plate or bandpass filter into the stainless steel light window outer ring, fix the O-ring seal (3), and screw the reaction cell light window cover assembly (2) onto the threads on the upper surface of the reaction cell main body shell (4), thus completing the reaction cell assembly. Install the assembled in-situ cell below the photomultiplier tube (PMT) detector through the mounting hole, calibrate the position, and complete the connection and fixation between the in-situ cell and the chemiluminescence detector. Under normal temperature conditions, load a certain amount of polymer sample into a sample dish and place it in the reaction cell sample slot (5). Using the pull-out rod head (8) and the guide rods (9-1, 9-2), push the sample slot (5) into the reaction cell main body shell (4), so that the sample and the external photomultiplier tube (PMT) detector are in the same vertical position, achieving the sealing of the reaction cell main body. Then, the reaction atmosphere gas is introduced into the reaction cavity of the main body of the reaction tank through the gas inlet connector (1), and the polymer sample passes through the reaction cavity of the main body of the reaction tank and is discharged from the gas outlet connector (6); the distributed control system (DCS) is turned on, the heating program is set, the chemiluminescence detection program is started synchronously, and the chemiluminescence signal of the system is monitored in real time, so as to obtain information such as the chemiluminescence behavior during the polymer reaction process.

[0039] In this example, low-density polyethylene (LDPE) film was used as the test material and assembled into the sample cell of the reactor. Detection was performed using a chemiluminescence analyzer, and the specific steps are as follows:

[0040] LDPE film samples with a thickness of 0.25 mm were prepared. First, at room temperature, a 0.5 cm × 0.5 cm LDPE film sample was placed in a sample dish and then placed in the sample chamber of the reaction cell. Next, the sample chamber containing the sample was smoothly pushed into the reaction cavity and locked in place. Then, air was introduced at a flow rate of 100 mL / min as the reaction atmosphere for a period of time. Finally, the temperature was programmed using a DCS to raise the temperature to the reaction temperature of 230 °C at a rate of 5 °C / min, and the temperature was maintained at 230 °C. Simultaneously, the chemiluminescence detector was activated to obtain the chemiluminescence kinetic curve of LDPE under these conditions. The results are shown in [Figure number missing]. Figure 6 .

Claims

1. An in-situ reaction cell adapted for chemiluminescence detection in polymer material reaction processes, characterized in that, The main shell of the reaction tank (4) is a stainless steel cuboid shell structure, which can be installed and fixed inside the chemiluminescence in-situ detection instrument for polymer material reaction process. The upper surface of the main shell of the reaction cell (4) is provided with mounting holes, which can be connected and installed below the photomultiplier tube (PMT) detector; The main body shell (4) of the reaction cell has 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) of the reaction cell have grooves (4-2) along the length of the main body of the reaction cell, and the grooves (4-2) are independent of the reaction cavity; the end of the main body shell (4) of the reaction cell has a central port (4-1) and a side port (4-3), 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), and the side ports (4-3) are two in number and are connected to the grooves (4-2) respectively; The guide rod includes a first pull guide rod (9-1) and a second pull guide rod (9-2). One end of the first pull guide rod (9-1) is fixedly connected to the sample groove (5), and the other end of the first pull guide rod (9-1) is fixed together with the pull rod head (8). The first pull guide rod (9-1) passes through the central port (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 dislodging from the groove (4-2). The front end and the end end of the reaction cavity inside the outer shell (4) of the main body of the reaction tank are respectively provided with an inlet (1) and an outlet (6) for the reaction atmosphere gas. The sample tank (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 guide rod (9-1) and led out from the second pull guide rod (9-2) to be connected to the external distributed control system (DCS). The heating program suitable for the target reaction is set so as to realize the controllable heating and accurate temperature measurement of the polymer sample reaction placed in the sample tank (5) of the reaction pool. 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.

2. The in-situ reaction cell adapted for chemiluminescence detection in 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.

3. An in-situ reaction cell adapted for chemiluminescence detection in 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.

4. An in-situ reaction cell adapted for chemiluminescence detection in polymer material reaction processes according to claim 1, characterized in that, 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.

5. An in-situ reaction cell adapted for chemiluminescence detection in polymer material reaction processes according to claim 1, characterized in that, The stainless steel outer ring center hole is fitted with an O-ring to serve as a replaceable fully transparent window for various emission wavelengths. 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 in the range of 300 to 650 nm to pass through.

6. An in-situ reaction cell adapted for chemiluminescence detection in polymer material reaction processes according to claim 1, characterized in that, The light window cover assembly (2) is in the same vertical position as the upper photomultiplier tube (PMT) detector and is connected to it. The chemiluminescence signal of the polymer reaction to generate intermediates can be transmitted to the photomultiplier tube (PMT) detector through the light window to realize real-time monitoring of the reaction process.

7. An in-situ reaction cell adapted for chemiluminescence detection in polymer material reaction processes according to claim 1, characterized in that, 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.

8. An in-situ reaction cell adapted for chemiluminescence detection in polymer material reaction processes according to claim 1, characterized in that, The reaction atmosphere gas is input from the inlet connector (1), flows through the polymer sample inside the reaction chamber, and is discharged from the outlet connector (6).

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