Sample preparation and testing integrated polymer material specific volume testing device and method

Abstract

The application relates to a sample preparation and testing integrated high polymer material specific volume testing device and method, and belongs to the field of material testing instrument equipment, testing technology and method. The sample preparation and testing integrated high polymer material specific volume testing device comprises a testing cavity unit, a sample preparation unit, a sealing unit, a pressure control system, a temperature control system, a displacement measurement system and a rack, comprises two plungers, one sample preparation plunger and one testing plunger, the sample preparation unit comprises a rotating block, a positioning element and a fastening element, sample preparation and testing of the measured high polymer material sample are completed at one time through rotation of the rotating block to realize rotation between sample preparation and sealing testing, the process is simple and easy to operate; the form of the measured high polymer material is not limited, the sample structure is simple, and the testing precision is higher; and the obtained specific volume data is used for supporting a database and a mathematical model.

Description

Technical Field

[0001] This invention relates to an integrated sample preparation and testing device and method for specific volume testing of polymer materials, belonging to the field of material testing instruments and equipment and testing technology and methods. Background Technology

[0002] Specific volume (V), the reciprocal of density, is a key property of polymer materials, primarily influenced by pressure (P) and temperature (T). The PVT characteristic of polymer materials refers to the relationship between pressure (P), specific volume (V), and temperature (T). This relationship mainly describes the change in specific volume of polymer materials under different temperature and pressure conditions. Specific volume is directly related to product quality and has significant guiding implications for polymer processing and molding. Relevant data can be used to calculate the density distribution, mass, shrinkage, and warpage of polymer products. It can also be used for numerical simulation and process control in polymer processing and molding, and further to guide the regulation of the shape and properties of polymer products, as well as the improvement of precision and quality.

[0003] The PVT (Polymer Transformation and Temperature) properties of polymer materials are obtained by measuring changes in specific volume under pressure and temperature variations. Patent JPH0420850A proposes a plunger-type direct-pressure PVT testing device, whose test chamber is completely sealed around its perimeter and bottom, allowing for the acquisition of PVT properties of a certain volume of material under high temperature and high pressure conditions; however, it does not consider sample preparation. Patent CN104267177A designs a simple, low-cost experimental device for PVT properties of plastic melts with different flow channel cross-sectional shapes, capable of testing the influence of different flow channel cross-sectional shapes on plastic PVT properties and melt flow rate; however, it also does not consider sample preparation. Patent CN201130179Y invented an indirect testing device for polymer PVT relationships, eliminating adverse factors such as mercury toxicity and volatility through the immiscibility of mercury and the device structure. Patent CN102636517A achieves the measurement of material PVT properties under high cooling rate conditions through simultaneous cooling of the inner and outer walls; however, it also does not consider sample preparation. Patent JPH0424545A proposes an indirect measurement device for the PVT properties of materials, using mercury as a closed medium for measurement, which suffers from the common problems of indirect testing methods. Patent CN209803148U replaces the closed medium mercury with a low-melting-point alloy, thereby greatly improving the test temperature range, but still does not eliminate the problems of other indirect testing methods. Patent CN2297001Y invented a mercury-free high-pressure physical property analyzer, including a high-pressure plunger pump, a PVT cylinder, a motor, a support, and control instruments. It also includes a swing mechanism, a bracket, and the bracket is fixedly connected to the pump body. The swing mechanism is connected to the pump body through the bracket, causing the pump to rotate and swing. The PVT cylinder is equipped with an observation window, and its inner cavity bottom has a conical hole and a V-shaped groove connected to it. The dew point and trace amounts of liquid can be observed using observation and monitoring equipment. However, this patent is mainly used for the determination of physical properties and phase research of black oil, volatile oil, condensate oil, dry and wet natural gas, and formation fluids. It is not applicable to polymer materials because polymer materials have high viscosity and different temperature and pressure change ranges, requiring specific sealing and control testing technologies to achieve the desired results. Patent CN102507383A discloses a capillary rheometer and a method for measuring the rheological properties of polymer materials. The capillary rheometer includes a barrel with an inlet at the front end and an outlet at the rear end. Inside the barrel are a first capillary channel, a feed channel, and a second capillary channel. The inlet is connected to the outlet via the first capillary channel, the feed channel, and the second capillary channel in sequence. The cross-sectional area of ​​the feed channel is larger than that of the first and second capillary channels. This invention can simultaneously measure the shear rheological parameters and tensile rheological parameters of polymer materials, but it is not used for specific volume testing. The specific volume testing of polymer materials requires a closed space, which this device does not yet possess.CN102507373A discloses a device and method for measuring the melting volume expansion rate / melting density of a material. The device includes a sample chamber placed in an electrically heated sample holder; a thermocouple, a PID intelligent temperature controller, and a relay jointly control the heating temperature and holding time; a probe is fixed on a clamping mechanism, and the entire device can move freely along a guide rod in the z-direction; the sample chamber containing a known mass of sample is vertically placed into the sample holder, the top cover is closed, a correction device is used to make the probe perpendicular to the bottom surface of the sample chamber, a protective gas is introduced, the temperature display switch is turned on, heating parameters are set, and heating begins. After the sample is completely melted, the protective gas is turned off, the probe penetrates the sample chamber to measure the liquid level, and heating is stopped, completing one measurement. Repeated measurements are used to obtain the average liquid level. The melting volume expansion rate and melting density of the sample are calculated using formulas. However, this invention does not consider sample preparation issues, making it difficult to achieve sealing and high-pressure testing conditions, and the lack of a cooling system prevents the determination of the specific volume change of the material under rapid cooling conditions. Besides traditional indirect measurement methods using sealed liquids, patent JP2670738B2 proposes an ultrasonic indirect non-destructive measurement method for the PVT properties of materials. This method obtains the PVT properties by adding an ultrasonic transmitter and receiver to a plunger-type testing device. However, it does not consider sample preparation, and the ultrasonic testing method requires correlation calibration between ultrasonic parameters and material parameters, and is affected by external noise, resulting in poor testing accuracy. Patent CN100560334C proposes an online testing method that can directly obtain the PVT properties of materials during actual processing, but it suffers from limited testing range and insufficient testing accuracy. Patent FR2771818A1 studies the influence of supercritical fluids on the transition between two condensed states and their application in polymer materials, but does not include the function of determining specific volume. FR2377042A1 is an apparatus for determining the behavior of viscoelastic materials during their production process. This apparatus includes a first cylinder for subjecting a test sample or specimen to initial compressive stress, a second cylinder for applying additional test stress to the sample, and a system for controlling stress relaxation in the material. Its characteristic feature is that two pistons move in mutually parallel directions. KR20020092531A discloses a sample determination device using a fluid capillary mechanism. This device can rapidly determine the rheological properties of polymers with a small sample volume in a short time. It uses an upper stage support rod with a load-bearing unit raised and lowered by a servo motor as a medium, mounted on the upper part of a lower stage. In the measuring device, the sample located on the upper surface of the central floating platform is filled into a capillary membrane, and the sample is measured by a controller. A cylindrical corner adhesive is mounted on the upper part of the lower stage, which can rotate. Multiple adsorption-desorption structures of the capillary membrane on this corner adhesive are formed at equal angles along the circumferential direction. This device cannot achieve specific volume measurement under high pressure conditions.EP0275825A1 describes a method for measuring volume changes, particularly in the measurement of shrinkage of thermosetting polymers during curing. The material to be measured is subjected to pressure such that a completely homogeneous sample is obtained without cracking or bubbling. This method allows for precise measurement of the shrinkage rate of synthetic resins during curing, especially during the gelation stage. EP0578785A1 discloses a capillary rheometer including a plunger pressure transducer assembly containing a liquid metal-filled capillary channel. When the plunger is pressed down onto the molten polymer, a diaphragm at the plunger end senses the pressure within the molten polymer and transmits this pressure to the liquid metal filler. This apparatus and method can only measure rheology and cannot determine specific volume. EP0598644A1 and US5347851A disclose a capillary rheometer device, including a housing, a plunger, the housing having a reservoir for receiving the plunger in a polymer melt, a mechanism for blocking the flow of the melt in the reservoir, and a drive mechanism for longitudinally driving the plunger within the reservoir so that one end of the plunger contacts the melt. A diaphragm connected to one end of the plunger deflects with the melt pressure in the reservoir. The device also includes mechanisms for measuring pressure, temperature, and displacement, which can obtain the PVT characteristics and surface shear viscosity characteristics of the polymer melt. This invention does not explicitly describe the sample preparation mechanism and the influence of the capillary during PVT testing. CN108982581A and EP3410095A1 disclose an apparatus for measuring the solidification degree / maturation degree and specific volume of packaging materials. The apparatus includes an upper load module configured to drive the rotation of an upper ball screw via an upper servo motor, causing a force plate connected to an upper balance screw to move downwards. This positions a lower module with a lower ball screw operated and moved by a lower servo motor, resulting in a corresponding displacement of the load connector assembly connected to the lower ball screw. An upper film cavity is modified and connected to the upper load module. A lower film cavity module is disposed on the lower load module. The displacement of the load connector assembly allows a push rod to move upwards. A heating tube maintains a constant temperature of the test object within the lower film cavity module. This invention is limited to testing packaging materials, and the sample form is limited to films, lacking the universality for measuring the specific volume of diverse polymer materials. US4313339A discloses a rheological testing apparatus and method, equipped with a device for forced mechanical mixing of the test material within a rheometer chamber. Preferably, it includes a pair of remotely arranged pistons that can be selectively connected and separated from each other, such that one piston can be used as a mixing device. When the test material is discharged, the pistons are connected to achieve overall movement. However, when using this apparatus to determine the specific volume of polymer materials, the capillary port needs to be sealed, and the problem of the influence of the material inside the capillary on the test accuracy is not solved.US5992222 discloses a high-precision high-pressure pump system, including a piston connected to a spindle, a spindle nut on the spindle, and a piston pump connected to the spindle nut; a cylinder body having a bore for receiving the piston; a mechanism providing relative rotation and axial movement between the piston and the cylinder body; the mechanism including means for causing relative rotational movement between the spindle and the spindle nut to compensate for the reaction force generated by a pressurized fluid sample in the cylinder bore when it is under-pressured; and a flexible element connected between the piston and the spindle to compensate for any axial misalignment between the piston and the cylinder bore. This invention does not mention any application area, is not applicable to the specific volume testing of polymer materials, and does not mention sample preparation apparatus and methods for polymer material testing. US9746406B2 discloses a testing machine for testing the flow viscosity of plastics, including a test piston, a test channel, at least one test weight, and a drive unit. The test piston can move through the test channel by means of the gravity of the test weight. The weight can be actuated by the drive unit between a starting position and an ending position. The actuated force enables the test piston to move in the direction of gravity, and the movement is accelerated compared to the reaction force of gravity. In the melt viscosity test, after heating, the thermoplastic is squeezed through the test channel by the test piston. In the measurement preparation step and / or cleaning step, the material is discharged along the direction of gravity under the influence of the actuated force. This patent is mainly used for testing the flow viscosity of plastics and does not mention the function of measuring the specific volume change after sealing the nozzle.

[0004] The patent survey above shows that some devices and methods can only test materials of a specific form or type. Furthermore, most devices and methods with similar structures are mainly used to characterize the rheological properties of materials but cannot determine specific volume. Specific volume determination of polymer materials needs to be carried out in a closed space. Existing polymer specific volume testing methods are mainly divided into three types: direct measurement, indirect measurement, and online measurement. 1) The testing device corresponding to the direct measurement method is mainly a plunger-cylinder structure, including a plunger, cylinder, sealing system, pressurization system, temperature control system, and sensor and data acquisition system. The plunger, cylinder, and sealing system form the test chamber, which is filled with the polymer sample. The plunger and pressurization system directly pressurize and depressurize the sample, controlling the pressure received. The temperature control system heats and cools the sample, controlling its temperature. A displacement sensor measures the plunger displacement to determine the volume and specific volume of the sample under different temperature and pressure conditions. 2) The testing device for indirect measurement methods mainly uses sealing liquid technology. It employs a high-temperature resistant liquid medium, such as mercury or a low-melting-point alloy, to encapsulate the polymer sample under test. The liquid medium and the encapsulated sample are sealed within the testing chamber. Pressure and temperature are transferred to the sample through the sealing liquid, and the specific volume change of the sample is calculated from the overall volume change of the sealing liquid. 3) The testing device for online measurement methods is directly integrated into the material processing device or equipment. During actual processing, a portion of the material is directly extracted into the testing chamber for real-time measurement.

[0005] The advantages of indirect measurement devices and methods lie in the fact that the presence of the sealing liquid ensures the uniformity of test temperature and pressure, prevents leakage of the tested sample, and maintains constant mass during the test. However, the presence of the sealing liquid causes a delay in pressure and temperature conduction, making it impossible to guarantee test accuracy under conditions of rapid pressure and temperature changes. Furthermore, the sealing liquid has significant limitations; it requires the selection of special high-temperature and high-pressure resistant sealing liquids such as mercury, which are often toxic and polluting. Additionally, it is unsuitable for test samples in liquid or powdered (non-particulate) polymeric forms. Liquid polymeric materials may react with the sealing liquid, and the small particle size of powdered polymeric materials can easily cause bubbles, suspension, and floating when the sealing liquid is added, making it impossible to determine the mass of the added polymeric material. Moreover, the volume change of the sealing liquid with temperature and pressure may introduce errors into the test results. The advantages of online measurement devices and methods are that they can easily obtain more realistic processing conditions. However, they are usually implemented by designing dedicated online molds, resulting in complex structures, insufficient sealing, difficulty in achieving high-temperature and high-pressure conditions, and very low test accuracy. Furthermore, they are not suitable for testing liquid polymeric materials. Compared to indirect and online measurement devices, direct measurement devices offer advantages such as simple principle, easy operation, no pollution, and high accuracy. They are also highly applicable to various polymer samples, suitable for both granular and powdered thermoplastic polymers, as well as gel-like and liquid thermosetting polymers. Currently, all commercially available PVT testing devices employ direct measurement. Direct measurement devices and methods, by directly controlling the pressure and temperature of the sample, can accurately obtain the specific volume change of the sample. Furthermore, by setting the experimental conditions, they can obtain specific volume changes that closely approximate those observed during actual processing. Existing commercially available PVT relationship testing devices for polymer materials include GÖTTFERT's PVT500, GOTECH's PVT6000, and INSTRON's CEAST series, all of which utilize direct measurement methods.

[0006] However, none of the relevant patented technologies explicitly define the sample preparation process. Direct measurement devices currently suffer from uneven temperature and pressure distribution, inaccurate measurements, and material leakage, leading to discrepancies between measurement results and theoretical results. These specific problems are primarily related to the sample preparation and sealing processes. Firstly, indirect measurement devices and methods do not involve a sample preparation process; the polymer material to be measured can be directly added to the sealing liquid for mixing. However, as mentioned earlier, for certain powdered and liquid polymer materials, problems such as chemical reactions, bubble encapsulation, suspension, and floating can easily occur during the addition of the sealing liquid, making it impossible to determine the mass of the added polymer material. Therefore, indirect measurement devices and methods are primarily suitable for granular polymer materials, and it is essential to ensure that the polymer particles do not contain any cavities. Secondly, online measurement devices and methods prepare polymer samples using polymer processing and molding equipment and online molds, offering the advantage of convenient sample preparation. However, limitations imposed by the processing and molding equipment, particularly the cavity structure, result in large sample volumes and uneven specific volume distribution within the sample due to processing and molding conditions, leading to significant testing errors. Furthermore, specialized cavity structures are required for displacement control and detection to convert to a test specific volume value; these complex structures also contribute to testing errors and present significant leakage problems. Moreover, they are unsuitable for testing liquid polymers. Therefore, compared to indirect and online measurements, direct measurement devices and methods offer the advantage of convenient sample preparation. The morphology of the polymer material being measured is unrestricted; it can be granular, powdered, or liquid, and can be pure polymer or polymer composites with various fillers of different components and concentrations. Additionally, the sample shape is simple and easy to seal, reducing leakage issues. Existing direct measurement devices, especially commercially available polymer material PVT relationship testing devices, are mainly modified from traditional capillary rheometer testing devices. These devices typically employ a plunger-cylinder structure, including a plunger, cylinder, sealing system, pressurization system, temperature control system, and sensors and data acquisition system. The plunger, cylinder, and sealing system form the testing chamber. Before testing, the polymer sample needs to fill the testing chamber. The sample preparation process requires careful attention to material addition, pre-melting, venting, and sealing. To address this, existing direct measurement devices utilize the principle of capillary rheometers, incorporating a capillary tube connected to the cylinder and testing chamber via a threaded sleeve. After pre-melting the added polymer sample, the plunger compacts the molten material and vents the air, then expels excess material from the capillary tube. The sealing system then seals both the material in the cylindrical testing chamber and the material in the capillary tube, allowing for the formal testing process to commence. Therefore, the sample preparation and sealing processes of these testing devices and methods primarily rely on capillary tubes. Because the residual material in the capillary tube was used as a sample throughout the entire formal testing process, it inevitably had a direct impact on the test results.From a theoretical perspective, since the capillary size is too small compared to the test chamber (typically around 10mm in diameter, while the capillary diameter is only 1mm or less), the actual pressure and temperature transmitted from the plunger pressure and cylinder temperature to the material inside the test chamber and capillary chamber will inevitably differ. Through long-term experiments using GÖTTFERT's PVT500, the inventors discovered that after each test, the residual samples removed showed morphological differences between the samples at the capillary and cavity locations, with some areas prone to blackening, indicating that the samples underwent certain degradation during the testing process. Obviously, the corresponding test data contained errors.

[0007] Furthermore, recent research has revealed that the specific volume (PVT) of polymer materials is not only related to pressure and temperature, but also to the process of pressure and temperature changes. Under different rates of pressure increase and decrease, and different rates of temperature increase and decrease, the specific volume of polymer materials varies to varying degrees. Therefore, the inventors proposed the concept of "process dependence" of the PVT relationship in polymer materials (reference "Influence of measurement processes on pressure-specific volume temperature relations of semi-crystalline polymer: Polypropylene, Polymer Testing, 2019, 78, 105992"). To fully understand the PVT relationship of polymer materials, it is necessary to construct conditions that can accurately control pressure and temperature, as well as the rates of pressure and temperature change, thereby obtaining the time effect of the PVT relationship. On the other hand, in the actual processing and molding of polymer materials, the phase change process is usually very rapid, and the corresponding temperature and pressure also change rapidly. For example, in the injection molding process of polymer materials, the high-temperature polymer material enters the mold cavity from the liquid state under rapid pressure increase conditions, followed by rapid cooling. The pressurization rate during the pressurization process can reach 200 MPa / s, and the cooling rate during the cooling process is close to 100 °C / s at the mold wall, while the cooling rate of the polymer material at the center of the mold cavity reaches 50 °C / s. However, existing PVT testing devices, although capable of controlling pressurization and depressurization rates to achieve high speeds, cannot control heating and cooling rates to achieve high speeds. Currently, the highest cooling rate of commercially available PVT testing devices is only about 30 °C / min, which is far from meeting actual processing conditions. Furthermore, considering that the pressure change rate during testing also has a significant impact on the PVT characteristics of polymer materials, it is necessary to invent a polymer specific volume testing device and method capable of achieving high temperature and high pressure change rates. Establishing a PVT characteristic database of polymer materials under actual processing conditions using this testing device and method is of great significance for guiding the actual processing and molding of related polymer materials. The relevant data can be used to establish new polymer specific volume prediction models considering rapid temperature and pressure changes, and further used in numerical simulation and process control, providing strong data support for the digitalization and intelligentization of polymer material processing and molding. However, existing direct measurement devices and methods that rely on capillary sampling and sealing are obviously not suitable for establishing test conditions of rapid temperature and pressure changes. The material inside the capillary cavity and the material inside the test cavity obviously have different response speeds to rapid temperature and pressure changes, which will lead to larger errors in the test results.

[0008] Therefore, there is an urgent need to construct an integrated sample preparation and testing device and method for polymer material specific volume testing, which can break away from the dependence of existing direct measurement devices and methods on capillary sample preparation and sealing, maintain the consistency of the pressure and temperature experienced by the polymer material under test during the test, improve the accuracy of polymer material specific volume testing under high temperature and high pressure conditions, and further improve its response accuracy to rapid temperature and pressure changes. Summary of the Invention

[0009] The purpose of this invention is to provide a testing device and method for measuring the specific volume change of polymer materials during temperature and pressure changes. This device integrates sample preparation and testing, features a simple sample shape without unnecessary capillary sections, is easy to seal, and reduces leakage. The form of the polymer material being tested is not limited; it can be granular, powdered, or liquid, and can be a pure polymer material or a polymer composite material with various fillers of different components and concentrations. It also has the ability to establish a wide range of temperature and pressure changes and to handle rapid temperature and pressure variations, while maintaining high testing accuracy.

[0010] The objective of this invention is achieved through the following technical solutions.

[0011] A polymer material specific volume testing device integrating sample preparation and testing includes a testing chamber unit, a sample preparation unit, a sealing unit, a pressure control system, a temperature control system, a displacement measurement system, and a frame. The device is characterized in that it includes two plungers, one for sample preparation and the other for testing.

[0012] Furthermore, the test chamber unit includes the test plunger and a cylinder. The cylinder body has a cylindrical through hole at its center, and a stepped hole and a threaded hole are provided at the lower end of the through hole. One end of the test plunger is provided with a groove and is connected to the connecting flange of the pressure control system. The other end of the test plunger is provided with a sealing ring structure and is equipped with a high-temperature resistant sealing ring.

[0013] Furthermore, the sample preparation unit includes a rotating block, a positioning element, and a fastening element. The rotating block is a stepped cylindrical shape. The positioning element has an eccentric stepped hole. The rotating block is installed in the stepped hole of the positioning element. The rotating block has a capillary through hole. During sample preparation, the lower end of the rotating block is provided with a groove to drive the rotating block to rotate. The capillary through hole rotates with the rotating block to below the cylindrical through hole of the test chamber unit cylinder. Before testing, the capillary through hole rotates with the rotating block to the outer side below the cylindrical through hole of the cylinder. The fastening element has threads on its exterior and is fixed to the lower part of the cylindrical through hole of the cylinder by threaded connection. The upper end face of the fastening element abuts against the lower end face of the positioning element.

[0014] Furthermore, the sample preparation plunger is used for compaction and venting, and one end of the sample preparation plunger is provided with a groove for connection to the pressure control system; the test plunger, cylinder and rotating block constitute a cylindrical test cavity, and the cylinder is provided with a small through hole that connects to the test cavity for installing a thermocouple to measure the temperature of the polymer material sample.

[0015] Furthermore, the sealing unit includes a force-increasing lever and a support plate. The support plate is positioned below the testing device. The lower end face of the force-increasing lever contacts the support surface of the support plate. During use, the upper end face of the force-increasing lever is pressed against the lower end face of the rotating block by lever force.

[0016] Furthermore, the pressure control system includes a pressure cylinder, a force sensor, and a connecting flange, with a locking block inside the connecting flange for locking and releasing the plunger.

[0017] Furthermore, the temperature control system includes a heater, a cooling unit, a thermocouple, and a controller. The cooling unit is provided with a cooling channel and is cylindrical in shape, tightly wrapping around the outside of the test chamber unit. The heater is tightly wrapped around the outside of the cooling unit. The thermocouple is located inside the cylinder, with the test tip close to the inside of the cylinder. At least one thermocouple test tip can be inserted into a tiny through hole on the cylinder and sealed.

[0018] Furthermore, the displacement measurement system includes a displacement sensor, a support, and a data acquisition system. The displacement sensor and the support are respectively mounted on the test bench plate of the frame and the connecting flange of the pressure control system.

[0019] Furthermore, the frame includes a base, a cylinder, a test bench plate, and a pressure cylinder plate. The cylinder connects the base, the test bench plate, and the pressure cylinder plate in series. The support plate of the sealing unit is also connected to the cylinder and the upper end of the base. The cylinder of the test chamber unit is located in the middle of the test bench plate, and the pressure cylinder is located in the middle of the pressure cylinder plate. The central axis of the pressure cylinder coincides with the central axis of the cylinder.

[0020] Furthermore, the test bench plate is also provided with a fixed plate, a heat insulation plate, a heat insulation ring and a protective cover. The fixed plate is fastened to the cylinder by bolts. The heat insulation plate is sandwiched between the fixed plate and the upper end face of the cylinder. The heat insulation ring is set at the upper end ring face of the cylinder to separate the cylinder from the test bench plate. The protective cover is set at the lower end of the test bench plate to cover the entire cylinder and the heater.

[0021] Furthermore, the diameter of the sample preparation plunger is smaller than the diameter of the test plunger.

[0022] Furthermore, the cooling unit of the temperature control system adopts air cooling, water cooling, oil cooling, or a combination of one, two, or three of these cooling methods. When a combined cooling method is adopted, the pipelines for conveying the cooling medium (air, water, or oil) are equipped with valves and control devices that enable the switching and conveying of water, air, and oil.

[0023] Furthermore, the rotating block and the positioning element are equipped with a locking structure. The extreme position of the rotating block's rotation is the sample preparation position, that is, the axis of the rotating block's capillary through hole coincides with the axis of the cylindrical part of the test chamber unit. The other extreme position of the rotating block's rotation is the sealing position, that is, the rotating block's capillary through hole is completely outside the cylindrical hole of the test chamber unit.

[0024] Furthermore, the lower end of the rotating block is provided with a groove, which is an internal hexagonal groove, that can drive the rotating block to rotate.

[0025] Furthermore, the height of the lever can be finely adjusted by adding shims.

[0026] Furthermore, the support plate is mounted on the frame cylinder by a fixing thread element, and the height of the support plate can be adjusted by the fixing thread element.

[0027] The steps of the integrated polymer material specific volume testing method using the integrated sample preparation and testing device of the present invention are as follows: Step 1: Set up the sample preparation unit. Install the rotating block, positioning element, and fastening element below the test chamber unit. Rotate the rotating block to the sealing position using a wrench, i.e., the capillary through hole of the rotating block is below the cylindrical through hole of the cylinder on the outside. Fix the fastening element using a torque wrench. Support the force-increasing lever of the sealing unit with the support plate, and press the rotating block further by amplifying the force of the lever on the lower end face of the rotating block. Step 2: Start the temperature control system, set the melting temperature and isothermal time of the polymer material to be tested, and control the temperature to be kept constant after the thermocouple measures the temperature to the set temperature. Step 3: Weigh a certain amount of polymer material and place it into the test chamber unit. After waiting for a certain period of time, install the sample preparation plunger onto the pressure control system, set the moving speed, and drive the sample preparation plunger to move down into the test chamber and continue to move through the pressure control system. Determine whether the sample preparation plunger has compacted the polymer material based on the pressure value measured by the pressure control system. After the pressure value stabilizes, drive the sample preparation plunger to move up out of the test chamber through the pressure control system. Step 4: Remove the sample preparation plunger from the pressure control system, install the test plunger onto the pressure control system, set the moving speed, drive the test plunger downward into the test chamber and continue moving through the pressure control system, determine whether the test plunger has compacted the polymer material based on the pressure value measured by the pressure control system, and stop the movement of the test plunger after the pressure value stabilizes. Step 5: Remove the lever and rotate the rotating block to the sample preparation position using a wrench, i.e., the capillary through-hole of the rotating block is below the cylindrical through-hole of the cylinder; set the initial sample height and the moving speed of the test plunger, and drive the test plunger to continue moving downward through the pressure control system. Excess polymer material inside the test chamber is squeezed out of the test chamber through the capillary through-hole of the rotating block under the pressure. Stop when the test plunger moves to the set position corresponding to the initial sample height. Step 6: Rotate the rotating block to the sealing position using a wrench, i.e., the capillary through hole of the rotating block is below and outside the cylindrical through hole of the cylinder. Fix the fastening element with a torque wrench, and tighten the torque according to the set torque to complete the preparation of the polymer material sample to be tested. Support the force-increasing lever of the sealing unit with the support plate, and press the rotating block further by lever force-increasing to achieve complete sealing of the test chamber. Step 7: Set the test temperature and pressure according to the required test conditions. Perform pressure increase and decrease operations through the pressure control system and control the pressure change and rate of change. Perform temperature increase and decrease operations through the temperature control system and control the temperature change and rate of change. Collect the displacement of the test plunger under different temperature and pressure conditions in real time through the displacement measurement system. Calculate the volume change of the sample inside the test chamber by the changes in the inner diameter of the test chamber and the displacement and initial displacement of the test plunger. Step 8: After the test is completed, the pressure is reduced to normal pressure through the pressure control system and the temperature is reduced to normal temperature through the temperature control system. After the pressure and temperature are stable, the fastening components are removed with a wrench. The test plunger is controlled by the pressure control system to push the sample out of the test chamber. The rotating block and positioning components are removed. The sample is moved out from the cylindrical through hole in the center of the cylinder. The test chamber unit and sample preparation unit are cleaned. Step 9: Measure the weight of the final removed cylindrical polymer material sample. Divide the converted volume by the weight to obtain the specific volume of the tested polymer material sample. Summarize the pressure, specific volume, and temperature data of the tested polymer material sample.

[0028] Furthermore, step 3 can be performed multiple times.

[0029] Furthermore, the weight of the polymer material to be tested placed in step 3 needs to be calculated based on the density of the polymer material to be tested and the volume of the test chamber before it is determined. The volume of the test chamber is calculated by using the initial height of the sample set in step 6 and the diameter of the cylindrical through hole at the center of the cylindrical body of the test chamber unit. The volume of the test chamber multiplied by the density of the polymer material to be tested is the required weight of the polymer material sample to be tested. Considering the influence of temperature and the needs of sample preparation, the weight of the polymer material to be tested placed is greater than the required weight of the polymer material sample to be tested.

[0030] Furthermore, the compaction pressure value in step 3 is set to be no less than 1 MPa.

[0031] Furthermore, in step 6, the tightening torque shall be no less than 70 Nm as set.

[0032] Beneficial effects 1) The present invention achieves the alternation between sample preparation and sealing test by configuring a sample preparation unit, especially by rotating a rotating block, thereby realizing the preparation and testing of the polymer material sample to be tested in one go. Moreover, the sample shape is simple and the sample preparation and testing process is simple and easy to operate. 2) The form of the polymer material being tested in this invention is not limited. It can be granular, powdered, or liquid. It can be a pure polymer material or a polymer composite material with various fillers of different components and concentrations. 3) The sample prepared by this invention does not have any extra "capillary" parts, so the pressure and temperature distribution inside the sample is more uniform during testing, resulting in higher testing accuracy. 4) The sample prepared by this invention has no excess "capillary" portion; it is equipped with two plungers, one for sample preparation and one for testing; the sample preparation plunger is used to vent air and compact the sample during sample preparation; the testing plunger is used to seal the sample and expel excess sample, which can ensure the initial volume accuracy of the tested sample; at the same time, the sealing unit cooperates with the testing unit, especially the fastening element and the force lever, to achieve better sealing, thereby greatly reducing the leakage problem during the testing process. 5) The temperature control system described in this invention is used to adjust the temperature and temperature change of the polymer material being tested inside the test chamber, and the pressure control system is used to adjust the pressure and pressure change of the polymer material being tested inside the test chamber; it can establish a wide range of temperature and pressure changes and has the function of rapid temperature and pressure change conditions. 6) The test bench plate of the present invention is also provided with a fixing plate, a heat insulation plate, a heat insulation ring and a protective cover, which can be used to connect the test chamber unit and its configured temperature control system to the frame, thereby effectively improving the heating and cooling efficiency of the temperature control system; 7) The diameter of the sample preparation plunger described in this invention is smaller than that of the test plunger. The sample preparation plunger does not need to consider sealing but mainly considers venting, while the test plunger mainly considers sealing. Therefore, the determination of the relevant diameter is conducive to ensuring the accuracy of sample preparation and testing. 8) The temperature control system of the present invention is further provided with air cooling, water cooling, oil cooling, or a combination of two or three of these cooling methods. When the test requires a low rate of temperature change, air cooling can be used to control the temperature change by delivering gas through an air pump, which can better ensure the control accuracy at a low rate of temperature change. When the test requires a high rate of temperature change, water cooling or oil cooling can be used to control the temperature change by delivering water or oil through a pump, which can achieve the purpose of high-speed cooling. Oil cooling can meet the cooling requirements of higher temperatures. 9) The rotating block and the positioning element described in this invention are equipped with a locking structure, which can make the rotating block obtain the sample preparation position or the sealing position in a simple and quick manner. 10) The height of the force-enhancing lever described in this invention can be finely adjusted by adding shims. The support plate is installed on the frame cylinder by fixing threaded elements. The height of the support plate can be adjusted by fixing threaded elements, which can ensure the sealing effect of the force-enhancing lever, greatly reduce material leakage problems, and ensure test accuracy.

[0033] 11) Step 3 of the present invention is performed in multiple steps to reduce the bubbles caused by the addition of the polymer material being tested, and to ensure that the prepared sample is free of pores and bubbles; the compaction pressure value in step 3 is set to be no less than 1 MPa, which can further ensure that the prepared sample is free of pores and bubbles. 12) In step 6 of the present invention, the tightening torque is set to be no less than 70 Nm, which can further ensure the sealing performance, prevent material leakage during the test, and improve the test accuracy.

[0034] 13) The data on the specific volume of polymer materials as a function of temperature and pressure obtained by the present invention can be used to support and guide research and development work such as database and mathematical model establishment, numerical calculation, simulation, new materials, new equipment and new processes; 14) The present invention may also have the function of a capillary rheometer, which can test the rheological properties of polymer materials under different temperature and pressure conditions, namely the change of viscosity with shear rate and the changes of viscous modulus and elastic modulus.

[0035] The testing systems and methods of the present invention have other features and advantages that will be apparent or set forth in detail from the accompanying drawings and detailed embodiments incorporated herein, which together serve to explain the particular principles of the invention. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the integrated sample preparation and testing device for polymer material specific volume testing according to the present invention; Figure 2 These are the front view, left view, and top view of the rotating block of the integrated sample preparation and testing polymer material specific volume testing device of the present invention; Figure 3 These are the front view, top view, and three-dimensional view of the positioning element of the integrated sample preparation and testing polymer material specific volume testing device of the present invention; Figure 4 This is a partial schematic diagram of steps 1 and 2 of the test method corresponding to the integrated sample preparation and testing polymer material specific volume testing device of the present invention. Figure 5 This is a partial schematic diagram of step 3 of the test method corresponding to the integrated sample preparation and testing polymer material specific volume testing device of the present invention; Figure 6 This is a partial schematic diagram of steps 4 and 5 of the test method corresponding to the integrated sample preparation and testing polymer material specific volume testing device of the present invention. Figure 7 This is a partial schematic diagram of steps 6 and 7 of the test method corresponding to the integrated sample preparation and testing polymer material specific volume testing device of the present invention. In the diagram: 1—Test chamber unit, 1-1—Test plunger, 1-2—Cylinder, 1-3—Sealing ring, 1-4—Micro-through hole, 2—Sample preparation unit, 2-1—Rotating block, 2-2—Positioning element, 2-3—Fastening element, 2-4—Capillary through hole, 2-5—Groove, 2-6—Sample preparation plunger, 2-7—Clamping structure, 3—Sealing unit, 3-1—Force boosting lever, 3-2—Support plate, 3-3—Gasket, 4—Pressure control system, 4-1—Pressure cylinder, 4-2—Force sensor, 4-3—Connecting flange, 4-4—Locking block, 5—Temperature control system, 5-1—Thermocouple, 5-2—Heater, 5-3—Cooling unit 5-4—Controller, 5-5—Cooling channel, 5-3-1—Air cooling, 5-3-2—Water cooling, 6—Displacement measurement system, 6-1—Displacement sensor, 6-2—Bracket, 6-3—Data acquisition system, 7—Frame, 7-1—Base, 7-2—Cylinder, 7-3—Test platform plate, 7-4—Pressure cylinder plate, 7-5—Fixed plate, 7-6—Heat insulation plate, 7-7—Heat insulation ring, 7-8—Protective cover, 8—Test chamber, 9—Polymer material, 10—Excess polymer material, 11—Sample, D0—Diameter of cylindrical through hole, D1—Diameter of sample preparation plunger end, D2—Diameter of test plunger end, H0—Initial height of sample.

[0037] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the invention. To better illustrate the embodiments, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Detailed Implementation

[0038] The preferred embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. In this embodiment, "upper," "lower," "left," "right," "front," and "rear" are defined according to the view directions in the accompanying drawings, which will be fully understood by those skilled in the art, and are not intended to limit the present invention in any way.

[0039] Example 1 A sample preparation and testing integrated polymer material specific volume testing device includes a testing chamber unit (1), a sample preparation unit (2), a sealing unit (3), a pressure control system (4), a temperature control system (5), a displacement measurement system (6), and a frame (7). The testing chamber unit (1) consists of a testing plunger (1-1) and a cylinder (1-2). The cylinder (1-2) has a cylindrical through-hole at its center, with a stepped hole and a threaded hole at the lower end. One end of the testing plunger (1-1) has a groove connected to the connecting flange (4-3) of the pressure control system (4). The other end of the testing plunger (1-1) has a sealing ring structure and is fitted with a high-temperature resistant sealing ring. The sealing ring (1-3); the sample preparation unit (2) consists of a rotating block (2-1), a positioning element (2-2), and a fastening element (2-3). The rotating block (2-1) is a stepped cylindrical shape. The positioning element (2-2) is provided with an eccentric stepped hole. The rotating block (2-1) is installed in the stepped hole of the positioning element (2-2). The rotating block (2-1) is provided with a capillary through hole (2-4). During sample preparation, the lower end of the rotating block (2-1) is provided with a groove (2-5) that can drive the rotating block to rotate. The capillary through hole (2-4) can rotate with the rotating block (2-1) to the bottom of the cylindrical through hole of the test chamber unit (1-2). Before testing, the capillary through hole ( 2-4) As the rotating block rotates, it moves to the outer side below the cylindrical through hole of the cylinder (1-2); the fastening element (2-3) is threaded on the outside and can be fixed to the lower part of the cylindrical through hole of the cylinder (1-2) by threaded connection, and the upper end face of the fastening element (2-3) abuts against the lower end face of the positioning element (2-2); the sample preparation unit (2) is also equipped with a sample preparation plunger (2-6) for compaction and venting, and one end of the sample preparation plunger (2-6) is provided with a groove for connection to the pressure control system (4); the test plunger (1-1), the cylinder (1-2) and the rotating block (2-1) constitute a cylindrical test cavity (8), and the cylinder (1-2) is provided with a small opening for connecting to the test cavity (8). Through hole (1-4) is used to install thermocouple (5-1) for measuring the temperature of polymer material sample (11); sealing unit (3) consists of force-increasing lever (3-1) and support plate (3-2). Support plate (3-2) is set below the test device. The lower end face of force-increasing lever (3-1) is in contact with the support surface of support plate (3-2). The upper end face of force-increasing lever (3-1) is pressed against the lower end face of rotating block (2-1) by lever force during use; pressure control system (4) consists of pressure cylinder (4-1), force sensor (4-2) and connecting flange (4-3). The connecting flange (4-3) is equipped with locking block (4-4) for locking and releasing plunger.The temperature control system (5) consists of a heater (5-2), a cooling unit (5-3), a thermocouple (5-1), and a controller (5-4). The cooling unit (5-3) is provided with a cooling channel (5-5) and is cylindrical in shape. It is tightly wrapped around the outside of the cylinder (1-2) of the test chamber unit (1). The heater (5-2) is tightly wrapped around the outside of the cooling unit (5-3). The thermocouple (5-1) is located inside the cylinder (1-2) with the test end close to the inside of the cylinder. At least one thermocouple (5-1) can be inserted into the tiny through hole (1-4) on the cylinder (1-2) and sealed. The displacement measurement system (6) includes a displacement sensor (6-1), a bracket (6-2), and a data acquisition system (6-3). The displacement sensor (6-1) and the bracket are respectively installed on the test bench plate (7-3) of the frame (7) and the connecting flange (4-3) of the pressure control system (4).The frame (7) consists of a base (7-1), a cylinder (7-2), a test bench plate (7-3), and a pressure cylinder plate (7-4). The cylinder (7-2) connects the base (7-1), the test bench plate (7-3), and the pressure cylinder plate (7-4) in series. The support plate (3-2) of the sealing unit (3) is also connected to the cylinder (7-2) and the upper end of the base (7-1). The cylinder (1-2) of the test chamber unit (1) is located in the middle position on the test bench plate (7-3). The pressure cylinder (4-1) is located in the middle position on the pressure cylinder plate (7-4). The central axis of the pressure cylinder (4-1) coincides with the central axis of the cylinder (1-2). The test bench plate (7-3) is also equipped with a fixed plate (7-5), a heat insulation plate (7-6), a heat insulation ring (7-7), and a protective cover (7-8). The fixed plate (7-5) is fastened to the cylinder (1-2) by bolts. The heat insulation plate (7-6) is sandwiched between the fixed plate (7-5) and the upper end face of the cylinder (1-2). The heat insulation ring (7-7) is located on the upper ring face of the cylinder (1-2) to separate the cylinder (1-2) from the test bench plate (7-3). The protective cover (7-8) is located at the lower end of the test bench plate (7-3) and encloses the entire cylinder (1-2) and the heater (5-2). The diameter (D1) of the sample preparation plunger end is smaller than the diameter (D2) of the test plunger end. The cooling unit (5-3) of the temperature control system (5) adopts a combination of air cooling (5-3-1) and water cooling (5-3-2). Valves and control devices for switching and transporting the cooling medium (air and water) are installed on the pipelines. A locking structure (2-7) is provided for the cooperation between the rotating block (2-1) and the positioning element (2-2). The extreme position of the rotating block (2-1) is the sample preparation position, i.e., the axis of the rotating block capillary through-hole (2-4) coincides with the axis of the test chamber unit cylinder (1-2). The other extreme position of the rotating block (2-1) is the sealing position, i.e., the rotating block capillary through-hole (2-4) is completely outside the cylindrical through-hole of the test chamber unit cylinder (1-2). A groove (2-5) with an internal hexagonal groove is provided at the lower end of the rotating block (2-1) to drive its rotation. The height of the lever (3-1) can be finely adjusted by adding shims (3-3). The support plate (3-2) is mounted on the frame cylinder (7-2) via a fixing threaded element (3-4), and the height of the support plate (3-2) can be adjusted via the fixing threaded element (3-4).

[0040] The steps of the sample preparation and testing method for specific volume testing of polymer materials using the integrated sample preparation and testing device of the present invention are as follows: Step 1: Set up the sample preparation unit (2), and install the rotating block (2-1), positioning element (2-2), and fastening element (2-3) below the test chamber unit (1). Rotate the rotating block (2-1) to the sealing position using a wrench, that is, the capillary through hole (2-4) of the rotating block (2-1) is located below the cylindrical through hole of the cylinder (1-2) on the outside. Fix the fastening element (2-3) using a torque wrench. Support the force-increasing lever (3-1) of the sealing unit (3) through the support plate (3-2), and place the other end face against the lower end face of the rotating block (2-1) and further press the rotating block (2-1) by lever force increase. Step 2: Start the temperature control system (5), set the melting temperature and constant temperature time of the polymer material to be tested, and control the thermocouple (5-1) to maintain the constant temperature after the temperature reaches the set temperature. Step 3: Weigh a certain weight of polymer material (9) and place it into the test chamber unit (1). After waiting for a certain period of time, install the sample preparation plunger (2-6) onto the pressure control system (4), set the moving speed, and drive the sample preparation plunger (2-6) to move down into the test chamber (8) and continue to move through the pressure control system (4). Determine whether the sample preparation plunger (2-6) has compacted the polymer material (9) according to the pressure value measured by the pressure control system (4). After the pressure value stabilizes, drive the sample preparation plunger (2-6) to move up out of the test chamber (8) through the pressure control system (4). Step 4: Remove the sample preparation plunger (2-6) from the pressure control system (4), install the test plunger (1-1) onto the pressure control system (4), set the moving speed, drive the test plunger (1-1) downward into the test chamber (8) through the pressure control system (4) and continue to move, determine whether the test plunger (1-1) has compacted the polymer material (9) according to the pressure value measured by the pressure control system (4), and stop the movement of the test plunger (1-1) after the pressure value stabilizes; Step 5: Remove the lever (3-1) and rotate the rotating block (2-1) to the sample preparation position using a wrench, i.e., the capillary through-hole (2-4) of the rotating block (2-1) is below the cylindrical through-hole of the cylinder (1-2); set the initial sample height (H0) and the moving speed of the test plunger (1-1), and drive the test plunger (1-1) to continue moving down through the pressure control system (4). The excess polymer material (10) inside the test chamber (8) is squeezed out of the test chamber (8) through the capillary through-hole (2-4) of the rotating block (2-1) by the extrusion pressure. Stop when the test plunger (1-1) moves to the set position corresponding to the initial sample height (H0); Step 6: Rotate the rotating block (2-1) to the sealing position using a wrench, i.e., the capillary through hole (2-4) of the rotating block (2-1) is located on the outside of the cylindrical through hole of the cylinder (1-2). Fix the fastening element (2-3) using a torque wrench, with the fastening torque set according to the set torque, to complete the preparation of the polymer material sample (11) to be tested. Support the force-increasing lever (3-1) of the sealing unit (3) through the support plate (3-2), and place the other end face against the lower end face of the rotating block (2-1) and further press the rotating block (2-1) by lever force-increasing to achieve complete sealing of the test chamber (8). Step 7: According to the required test conditions, set the test temperature and pressure, perform pressure increase and decrease operations through the pressure control system (4) and control the pressure change and rate of change, perform temperature increase and decrease operations through the temperature control system (5) and control the temperature change and rate of change, collect the displacement of the test plunger (1-1) under different temperature and pressure conditions through the displacement measurement system (6) in a timely manner, and calculate the volume change of the sample (11) inside the test cavity (8) by the inner diameter of the test cavity (8) and the displacement and initial displacement change of the test plunger (1-1); Step 8: After the test is completed, the pressure is reduced to normal pressure through the pressure control system (4), and the temperature is reduced to normal temperature through the temperature control system (5). After the pressure and temperature are stable, the fastening element (2-3) is removed by wrench, and the test plunger (1-1) is controlled by the pressure control system (4) to push the sample (11) out of the test chamber (8). The rotating block (2-1) and the positioning element (2-2) are removed, and the sample (11) is moved out from the cylindrical through hole in the center of the cylinder (1-2). The test chamber unit (1) and the sample preparation unit (2) are cleaned. Step 9: Measure the weight of the final removed cylindrical polymer material sample (11), and obtain the specific volume of the tested polymer material sample (11) by dividing the converted volume by the weight. Summarize the pressure, specific volume, and temperature data of the tested polymer material sample (11).

[0041] The precautions for the above test steps are as follows: Step 3 can be performed multiple times; the weight of the polymer material (9) to be tested in Step 3 needs to be calculated based on the density of the polymer material and the volume of the test chamber before it is determined. The volume of the test chamber is calculated by the initial height (H0) of the sample set in Step 6 and the diameter (D0) of the cylindrical through hole at the center of the cylinder (1-2) of the test chamber unit (1). The volume of the test chamber (8) multiplied by the density of the polymer material to be tested is the weight of the polymer material sample (11) to be tested. Considering the influence of temperature and the needs of sample preparation, the weight of the polymer material (9) to be tested is greater than the weight of the polymer material sample (11) to be tested; the compaction pressure value in Step 3 is set to be no less than 1MPa; the tightening torque in Step 6 is set to be no less than 70Nm.

[0042] This invention includes, but is not limited to, the above embodiments. Any equivalent substitutions or partial improvements made under the spirit and principles of this invention shall be considered to be within the scope of protection of this invention.

Claims

1. A polymer material specific volume testing device integrating sample preparation and testing, comprising a testing chamber unit, a sample preparation unit, a sealing unit, a pressure control system, a temperature control system, a displacement measurement system, and a frame, characterized in that: The integrated polymer material specific volume testing device includes two plungers, one for sample preparation and one for testing. The testing chamber unit includes the testing plunger and a cylinder. The cylinder has a cylindrical through-hole at its center, with a stepped hole and a threaded hole at its lower end. One end of the testing plunger has a groove for connection to a pressure control system flange, and the other end has a sealing ring structure with a high-temperature resistant sealing ring. The sample preparation unit includes a rotating block, a positioning element, and a fastening element. The rotating block is a stepped cylinder. The positioning element has an eccentric stepped hole, and the rotating block is installed in the stepped hole of the positioning element. The rotating block also has a capillary through-hole. During sample preparation, the rotating block rotates... The lower end of the rotating block is provided with a groove for driving the rotating block to rotate. The capillary through hole rotates with the rotating block to the lower part of the cylindrical through hole of the test chamber unit cylinder. Before the test, the capillary through hole rotates with the rotating block to the lower outer side of the cylindrical through hole of the cylinder. The fastening element is provided with threads on the outside and is fixed to the lower part of the cylindrical through hole of the cylinder by threaded connection. The upper end face of the fastening element abuts against the lower end face of the positioning element. The sample preparation plunger is used for compaction and venting. One end of the sample preparation plunger is provided with a groove for connection to the pressure control system. The test plunger, cylinder and rotating block constitute a cylindrical test chamber. The test plunger is used for sealing the sample and pressing out excess sample to ensure the initial volume accuracy of the tested sample. The diameter of the sample preparation plunger is smaller than the diameter of the test plunger.

2. The integrated sample preparation and testing polymer material specific volume testing device as described in claim 1, characterized in that: The cylinder is provided with a tiny through hole that connects to the test chamber, which is used to install a thermocouple for measuring the temperature of the polymer material sample.

3. The integrated sample preparation and testing device for polymer material specific volume testing as described in claim 1, characterized in that: The sealing unit includes a force-increasing lever and a support plate. The support plate is located below the testing device. The lower end face of the force-increasing lever contacts the support surface of the support plate. During use, the upper end face of the force-increasing lever is pressed against the lower end face of the rotating block by the lever force.

4. The integrated sample preparation and testing device for polymer material specific volume testing as described in claim 1, characterized in that: The pressure control system consists of a pressure cylinder, a force sensor, and a connecting flange. The connecting flange has a locking block inside for locking and releasing the plunger.

5. The integrated sample preparation and testing device for polymer material specific volume testing as described in claim 1, characterized in that: The temperature control system includes a heater, a cooling unit, thermocouples, and a controller. The cooling unit is equipped with cooling channels and is cylindrical in shape, tightly wrapping around the outside of the test chamber unit. The heater is tightly wrapped around the outside of the cooling unit. The thermocouples are located inside the cylinder, with the test tips close to the inside of the cylinder. At least one thermocouple test tip can be inserted into a tiny through hole on the cylinder and sealed.

6. The integrated sample preparation and testing device for polymer material specific volume testing as described in claim 1, characterized in that: The frame includes a base, a cylinder, a test bench plate, and a pressure cylinder plate. The cylinder connects the base, the test bench plate, and the pressure cylinder plate in series. The support plate of the sealing unit is also connected to the cylinder and the upper end of the base. The cylinder of the test chamber unit is located in the middle of the test bench plate, and the pressure cylinder is located in the middle of the pressure cylinder plate. The central axis of the pressure cylinder coincides with the central axis of the cylinder.

7. The integrated sample preparation and testing polymer material specific volume testing device as described in claim 6, characterized in that: The test bench plate is also equipped with a fixed plate, a heat insulation plate, a heat insulation ring, and a protective cover. The fixed plate is fastened to the cylinder by bolts. The heat insulation plate is sandwiched between the fixed plate and the upper end face of the cylinder. The heat insulation ring is set at the upper end ring face of the cylinder to separate the cylinder from the test bench plate. The protective cover is set at the lower end of the test bench plate to cover the entire cylinder and the heater.

8. A method for testing the specific volume of polymer materials that integrates sample preparation and testing, characterized in that: The method is performed on the integrated sample preparation and testing polymer material specific volume testing device as described in any one of claims 1-7, and the specific steps of the method are as follows: Step 1: Set up the sample preparation unit. Install the rotating block, positioning element, and fastening element below the test chamber unit. Rotate the rotating block to the sealing position using a wrench, i.e., the capillary through hole of the rotating block is below the cylindrical through hole of the cylinder on the outside. Fix the fastening element using a torque wrench. Support the force-increasing lever of the sealing unit with the support plate, and press the rotating block further by amplifying the force of the lever on the lower end face of the rotating block. Step 2: Start the temperature control system, set the melting temperature and isothermal time of the polymer material to be tested, and control the temperature to be kept constant after the thermocouple measures the temperature to the set temperature. Step 3: Weigh a certain amount of polymer material and place it into the test chamber unit. After waiting for a certain period of time, install the sample preparation plunger onto the pressure control system, set the moving speed, and drive the sample preparation plunger to move down into the test chamber and continue to move through the pressure control system. Determine whether the sample preparation plunger has compacted the polymer material based on the pressure value measured by the pressure control system. After the pressure value stabilizes, drive the sample preparation plunger to move up out of the test chamber through the pressure control system. Step 4: Remove the sample preparation plunger from the pressure control system, install the test plunger onto the pressure control system, set the moving speed, drive the test plunger downward into the test chamber and continue moving through the pressure control system, determine whether the test plunger has compacted the polymer material based on the pressure value measured by the pressure control system, and stop the movement of the test plunger after the pressure value stabilizes. Step 5: Remove the lever and use a wrench to rotate the rotating block to the sample preparation position, i.e., the capillary through-hole of the rotating block is below the cylindrical through-hole of the cylinder. The initial height of the sample and the moving speed of the test plunger are set. The test plunger is driven to continue to move downward through the pressure control system. Excess polymer material inside the test chamber is squeezed out of the test chamber through the capillary through-hole of the rotating block under the pressure. The test plunger stops when it moves to the set position corresponding to the initial height of the sample. Step 6: Rotate the rotating block to the sealing position using a wrench, i.e., the capillary through hole of the rotating block is below and outside the cylindrical through hole of the cylinder. Fix the fastening element with a torque wrench, and tighten the torque according to the set torque to complete the preparation of the polymer material sample to be tested. Support the force-increasing lever of the sealing unit with the support plate, and press the rotating block further by lever force-increasing to achieve complete sealing of the test chamber. Step 7: Set the test temperature and pressure according to the required test conditions. Perform pressure increase and decrease operations through the pressure control system and control the pressure change and rate of change. Perform temperature increase and decrease operations through the temperature control system and control the temperature change and rate of change. Collect the displacement of the test plunger under different temperature and pressure conditions in real time through the displacement measurement system. Calculate the volume change of the sample inside the test chamber by the changes in the inner diameter of the test chamber and the displacement and initial displacement of the test plunger. Step 8: After the test is completed, the pressure is reduced to normal pressure through the pressure control system and the temperature is reduced to normal temperature through the temperature control system. After the pressure and temperature are stable, the fastening components are removed with a wrench. The test plunger is controlled by the pressure control system to push the sample out of the test chamber. The rotating block and positioning components are removed. The sample is moved out from the cylindrical through hole in the center of the cylinder. The test chamber unit and sample preparation unit are cleaned. Step 9: Measure the weight of the final removed cylindrical polymer material sample. Divide the converted volume by the weight to obtain the specific volume of the tested polymer material sample. Summarize the pressure, specific volume, and temperature data of the tested polymer material sample.

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