An in-situ analysis apparatus and method for polymer samples containing impurities

Abstract

This disclosure provides an in-situ analysis device and method for polymer samples containing impurities. The device includes a filter assembly, a sample vial, an injector, and an analyzer. The filter assembly is placed in the sample vial, allowing the dissolution and filtration of the polymer sample to be carried out simultaneously before analysis. This avoids impurities such as fillers and inorganic particles in the polymer sample from entering the chromatographic column and other components of the analyzer, which could significantly affect their performance. This improves data reliability and analytical efficiency, eliminates the need for additional solvents, is simple to operate, and is environmentally friendly and pollution-free.

Description

Technical Field

[0001] This disclosure relates to the field of liquid chromatography technology, and more specifically, to an in-situ analysis apparatus and method for polymer samples containing impurities. Background Technology

[0002] Polyolefins, as a bulk synthetic polymer, are widely used in many fields of production and daily life due to their light weight, low cost, and wide range of applications. The material structure of polyolefins is a key factor determining their performance. Complete and accurate characterization of the chain structure of polyolefin materials can provide guiding information for the selection of polyolefin catalyst technologies and production processes, provide a scientific basis for improving their processing conditions and performance, help to construct structure-property relationships for polyolefin materials, meet the quality control and high-end product requirements during the use of polyolefin materials, and powerfully promote the rational application of polyolefin materials and the research and development of new products. Parameters such as the molecular weight and its distribution, "chemical composition distribution (CCD)" or "short branched distribution (SCBD)" of polyolefins, isotacticity and its distribution, and comonomer composition and its distribution play an important role in the performance of polyolefin materials. Currently, the industry commonly uses chromatographic methods to measure molecular weight and its distribution, CCD and other parameters, such as high-temperature gel permeation chromatography (HT-GPC), temperature gradient interaction chromatography (HT-TGIC), temperature elution fractionation (TREF), crystallization elution fractionation (CEF), crystallization analysis (CRYSTEX, CRYSTEX QC), solvent gradient interaction chromatography (HTLC), crossfractionation, and two-dimensional solvent gradient interaction analysis.

[0003] However, to meet the various high-performance requirements of polyolefins, a variety of auxiliaries, opening agents, and large amounts of fillers such as carbon black and titanium dioxide are typically added during the production and processing of polyolefins. These fillers are not soluble in the solvents used in analytical testing, causing serious damage to the aforementioned analytical methods and instruments. For example, in analytical instruments, they can severely affect the normal transport of the analytical solution in the liquid flow pipeline, hinder the normal operation of valve rotors, and render measuring instruments and devices unable to perform their testing functions properly. Furthermore, in these chromatographic separation techniques, precise chromatographic column packing is a crucial component of the analysis. The fillers in polyolefins easily deposit and diffuse into the pores of the chromatographic column packing, and can also cover many parts of the instrument flow channels and detectors, making it impossible to accurately characterize parameters such as the molecular weight and distribution of polyolefins.

[0004] Therefore, there is an urgent need for a device and method that can simultaneously perform the dissolution and filtration of impurities in polymer solutions, avoiding the influence of other factors, and analyze the results. This would improve data reliability, simplify operation, reduce the use of organic solvents, and be environmentally friendly. Summary of the Invention

[0005] The purpose of this disclosure is to provide an apparatus and method that can effectively filter impurities in polymer solutions while avoiding the influence of other factors, and simultaneously perform in-situ analysis of polymer solutions, thereby improving analytical testing efficiency and data reliability. The apparatus is simple to operate, does not require additional solvents, and is environmentally friendly and pollution-free.

[0006] To achieve the above objectives, this disclosure provides an in-situ analysis device for polymer samples containing impurities, the device comprising a filter assembly, a sample vial, a sample injector, and an analyzer; The sample vial is used to place and / or fix the filter assembly and to contain the solvent used to dissolve the polymer sample; the sample vial is provided with a sample injector port, one end of the sample injector is connected to the sample injector port, and the other end of the sample injector is connected to the analyzer, so that the polymer sample solution dissolved and filtered in the sample vial is injected into the analyzer for analysis.

[0007] Optionally, the filtration assembly includes a filter screen and a sample chamber; the filter screen is used to enclose and / or block the filtration of the polymer sample, and the sample chamber is used to fix the filter screen. Optionally, the filter screen has 2-10 layers, preferably 3-7 layers, more preferably 3-5 layers; the mesh size is 400-3000 mesh, preferably 2000-2500 mesh.

[0008] Optionally, the filter assembly is an embedded filter assembly, embedded within the sample vial. The polymer sample is directly added to the sample vial, and then the filter assembly is placed inside the sample vial, so that the polymer sample to be tested exists between the inside of the sample vial and the outside of the filter assembly. Solvent is added to the sample vial, contacting the polymer sample to be tested, allowing the dissolved polymer sample to enter the interior of the filter assembly and be injected into the analyzer through the sample injector. The filter assembly is a filter screen; the solvent is directly added to the interior of the filter screen, flows out of the filter screen through the pores, and directly contacts the polymer sample to be tested. The dissolved polymer sample diffuses into the interior of the filter assembly through the pores, while impurities remain between the outside of the filter assembly and the inside of the sample vial.

[0009] Alternatively, the filter assembly can be an external filter assembly, in which the polymer sample is wrapped and then placed in the sample bottle; the solvent can be added to the filter assembly before or after it is placed in the sample bottle.

[0010] Optionally, the filter assembly consisting of multiple layers of filter screens can be semi-cylindrical or other geometric shapes.

[0011] Optionally, the filter component is positioned no higher than the sampling port of the injector to avoid obstructing the sampling port.

[0012] Optionally, the filter component is selected from any one of metal filter components, polymer filter components and inorganic filter components, and does not react with the polymer sample and solvent, nor is it dissolved by the solvent.

[0013] Optionally, the analyzer includes at least one of a high-temperature gel permeation chromatograph, a crystallization elution fractionation instrument, a xylene soluble matter analyzer, a polymer intrinsic viscosity analyzer, and a temperature gradient interaction chromatograph.

[0014] On the other hand, this disclosure provides an in-situ analysis method for polymer samples containing impurities. This method uses the aforementioned apparatus and specifically includes the following steps: The polymer sample to be tested is encapsulated in a filter assembly, allowing the polymer sample to dissolve in the solvent in the sample vial and then filtered through the filter assembly. The filtered polymer solution is then injected into the analyzer for analysis via a sample injector.

[0015] Optionally, the polymer sample to be tested includes polyolefins; the polymer sample to be tested is a powder, granules, or strip-shaped solid with a particle size not smaller than the pore size corresponding to the mesh size of the filter screen, so that insoluble impurities in the polymer sample to be tested will not pass through the filter screen.

[0016] Optionally, the solvent includes at least one of chlorobenzene, dichlorobenzene, and trichlorobenzene; The dissolution conditions include: a temperature of 60-200℃, a time of 20-1000 min, a shaking frequency of 10-1000 rpm, and the concentration of the polymer sample to be tested is preferably 0.1-10 mg / mL.

[0017] Through the above technical solution, this disclosure provides an in-situ analysis device and method for polymer samples containing impurities. The device is equipped with a filter assembly, a sample vial, an injector, and an analyzer. The filter assembly is set in the sample vial, so that the dissolution and filtration of the polymer sample are carried out simultaneously, followed by analysis. This avoids impurities such as fillers and inorganic particles in polyolefins from entering the chromatographic column and other parts of the instrument, which would have a significant impact on their performance. This improves data reliability and analytical efficiency, and is environmentally friendly and pollution-free.

[0018] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 Image of a polypropylene (PP) sample containing 12 wt% carbon black.

[0020] Figure 2 This is a structural diagram of a sample vial containing filter components (left: embedded; right: external).

[0021] Figure 3 The diagram shows the dissolution state of PP samples at high temperature with and without external filter components (left and right sides).

[0022] Figure 4 This is a diagram showing the state of PP sample precipitated after dissolution at room temperature, including an external filter component.

[0023] Figure 5 Images of polyethylene (PE) samples containing impurities with different morphologies.

[0024] Figure 6 This is a diagram showing the melting state of a PE sample containing an external filter element at high temperature. Detailed Implementation

[0025] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure.

[0026] This disclosure provides an in-situ analysis device for polymer samples containing impurities, the device including a filter assembly, a sample vial, a sample injector, and an analyzer; The sample vial is used to place and / or fix the filter assembly and to contain the solvent used to dissolve the polymer sample; The sample vial is equipped with a sample inlet. One end of the sample injector is connected to the sample inlet, and the other end of the sample injector is connected to the analyzer, so that the polymer sample solution dissolved and filtered in the sample vial is injected into the analyzer for analysis.

[0027] This disclosure provides an in-situ analysis device for polymer samples containing impurities. The device includes a filter assembly, a sample vial, a sample injector, and an analyzer. The polymer sample containing impurities is dissolved in a solvent within the sample vial and then filtered through the filter assembly. After filtration, the impurities in the polymer sample remain encapsulated within the filter assembly. The filtered polymer solution is then injected into the analyzer through the sample port via the sample injector for analysis. This device effectively prevents impurities such as fillers and inorganic particles in polyolefins from entering the analyzer and significantly impacting its performance, thus avoiding maintenance costs and instrument downtime. It integrates dissolution, filtration, and analysis, improving data accuracy and analytical testing efficiency.

[0028] Optionally, the filtration assembly includes a filter screen and / or a sample chamber; the filter screen is used to enclose and / or block the filtration of the polymer sample; the sample chamber is used to fix the filter screen.

[0029] Optionally, the filter screen can be repeatedly folded to wrap the polymer sample to prevent leakage. The folded filter screen has 2-10 layers, preferably 5-7 layers, and a mesh size of 400-3000 mesh, preferably 2300-2500 mesh. The specific folding method of the filter screen can be adjusted according to actual needs.

[0030] Optionally, the filter assembly is an embedded filter assembly, installed within the sample vial. The polymer sample to be tested is directly added to the sample vial, and then the filter assembly, composed of multiple layers of filter screens, is placed inside the sample vial, with the polymer sample to be tested positioned between the outside of the filter screens and the inside of the sample vial. The solvent is directly added to the interior of the filter assembly, flows out through the pores, and comes into direct contact with the polymer sample to be tested. The dissolved polymer sample diffuses through the pores into the interior of the filter assembly, while insoluble impurities in the polymer sample to be tested remain between the outside of the filter assembly and the inside of the sample vial.

[0031] Alternatively, the filter assembly is an external filter assembly, in which the polymer sample is wrapped and then placed in a sample bottle; the sample bottle contains a solvent or the solvent is added after the filter assembly is placed in the sample bottle, so that the polymer sample to be tested dissolves in the sample bottle.

[0032] Optionally, the position of the filter component is not higher than the sampling port to prevent impurities obtained from filtering the polymer sample inside the filter component from entering the analyzer during sample injection.

[0033] Optionally, the filter assembly is selected from any one of metal filter assemblies, polymer filter assemblies, and inorganic filter assemblies, and does not react with the polymer sample and solvent.

[0034] Optionally, the filter assembly can be semi-cylindrical or other geometric shapes.

[0035] Optionally, the analyzer includes at least one of a high-temperature gel permeation chromatograph, a crystallization elution fractionation instrument, a xylene-soluble matter analyzer, a polymer intrinsic viscosity analyzer, and a temperature gradient interaction chromatograph. The specific analyzer disclosed herein can be adjusted according to the type of polymer sample being measured.

[0036] Optionally, the dissolution conditions and sample concentration can be adjusted according to actual needs and measurement methods.

[0037] On the other hand, this disclosure provides an in-situ analysis method for polymer samples containing impurities, which uses the above-mentioned apparatus and includes the following steps: The polymer sample to be tested is encapsulated in a filter assembly, allowing the polymer sample to dissolve in the solvent in the sample vial and then filtered through the filter assembly. The filtered polymer solution is then injected into the analyzer for analysis via a sample injector.

[0038] The method provided in this disclosure involves dissolving the polymer sample to be tested in a solvent in a sample vial, filtering impurities from the polymer sample through a filter assembly, and then injecting the filtered polymer sample solution into the analyzer through a sampler via the sampling port on the sample vial for analysis. This method avoids impurities from entering the analyzer and affecting its performance, is simple to operate, and improves the reliability of the data and the efficiency of the analysis.

[0039] Optionally, the polymer sample to be tested includes polyolefins; the polymer sample to be tested is a powder, granules, or strip-shaped solid with a particle size not less than the pore size corresponding to the mesh size of a filter screen. Optionally, the impurities in the polymer sample to be tested include any one of inert fillers such as carbon black, titanium dioxide, and metal oxides, or other insoluble polymers.

[0040] Optionally, the solvent includes at least one of chlorobenzene, dichlorobenzene, and trichlorobenzene; the dissolution conditions include: a temperature of 60-200℃, a time of 20-1000 min, a shaking frequency of 10-1000 rpm, and the concentration of the polymer sample to be tested is preferably 0.1-10 mg / mL.

[0041] The particle size of the polymer sample to be tested provided in this disclosure is not smaller than the pore size corresponding to the mesh size of the filter component, so that the polymer sample to be tested is completely dissolved under the above conditions, and the insoluble substances are still encapsulated in the filter component to achieve the purpose of filtration.

[0042] The present invention will be further described in detail below through examples.

[0043] Example 1 Weigh 44 mg of a polypropylene (PP) sample containing 12 wt% carbon black using a precision analytical balance. Figure 1As shown (granular material, particle size 30-60 mesh), the sample is wrapped in a 2800-mesh metal filter (6cm long x 4cm wide). The metal filter is folded upwards along the bottom edge, extending beyond the polymer sample to be tested. The left and right ends of the filter are folded to 1.25cm from the bottom to prevent leakage of the polymer sample. This process is repeated five times, effectively filtering the polymer sample six times. The folded metal filter is then fixed in a cylindrical metal sample chamber (material: 304 stainless steel, manufacturer: Qianchuang Filter) with a top diameter of 1.19cm, a bottom diameter of 1cm, and a height of 1.5cm. The metal sample chamber is then placed into a 20mL sample bottle. The specific structure is as follows... Figure 2 (Right figure) shows the external structure. 10 mL of trichlorobenzene was added to the sample vial, and the solution was dissolved at 160°C for 60 min. The dissolution of the PP sample is as follows: Figure 3 As shown in the right figure.

[0044] Comparative Example 1 The comparative example uses the same sample as in Example 1, such as... Figure 1 As shown; the method is the same, the difference being that no metal filter and sample chamber are used for encapsulation, i.e., no filter assembly is included, and the dissolution of the polyethylene sample is as follows. Figure 3 As shown in the left figure.

[0045] pass Figure 3 As can be seen, in Comparative Example 1, the sample bottle without the filter component (left figure) showed a black liquid after the PP sample was dissolved at 160℃ for 60 minutes. This indicates that after the PP sample dissolved, the carbon black filler in the PP sample was dispersed in the polymer solution and could not dissolve. It would then directly enter the analytical instrument, damaging it and preventing further analysis. Example 1 contained (… Figure 3 (Right Figure) In the sample bottle of the filter assembly, after the PP sample dissolved at 160℃ for 60 minutes, the solution in the sample bottle was clear and transparent, with no black carbon black filler. This indicates that after the PP sample dissolved, the carbon black in the PP sample was encapsulated within the metal filter screen and metal sample chamber, effectively filtering and separating the carbon black from the polyolefin polymer solution at high temperature. This prevents carbon black from entering during subsequent testing, protecting the analytical instrument while completing the analysis. Furthermore, as the temperature decreases, the polymer dissolved in the solvent precipitates out, but the carbon black impurities remain in the filter assembly, such as... Figure 4 As shown, the liquid in the sample bottle is divided into upper and lower layers. After the polymer sample dissolved at high temperature is cooled to room temperature, it precipitates out as white and is suspended above the liquid.

[0046] Example 2 2.63 mg of homopolymer polypropylene containing impurities was weighed using a precision analytical balance and wrapped in a 2400-mesh metal filter (3 cm long × 2 cm wide). The filter was then fixed in a cylindrical metal sample chamber with an upper diameter of 0.85 cm, a lower diameter of 0.68 cm, and a height of 0.41 cm. The sample was placed in a 10 mL sample vial with a concentration of 0.3 mg / mL. The sample was then dissolved at 160 °C for 180 min and subjected to GPC (high-temperature gel permeation chromatography, Spain) testing. The instrument status and test results were observed, and the specific results are shown in Table 1.

[0047] Table 1 GPC Test Results

[0048] Comparative Example 2 The comparative example used the same sample and method as Example 2, except that it did not use a metal filter and sample chamber for wrapping, i.e., it did not contain a filter component. The condition of the GPC instrument and the test results were observed.

[0049] As shown in Table 1, the recovery rate of Example 2 was 72.23%, far less than 100%, indicating that the filtration assembly provided in this disclosure can successfully separate impurities and polypropylene polymers in the sample. Impurities are trapped in the filtration assembly, while the polymers in the solvent successfully pass through the filtration assembly and enter the flow channel of the GPC analyzer through the injector. The GPC analyzer then proceeds through the tubing, column, and detector for testing, with no impact on instrument components during the testing process. In contrast, in Comparative Example 2, no filtration device was used to filter the polypropylene sample before GPC testing. After the homopolymer polypropylene sample entered the injector, it clogged the column, affecting the valve rotor and the normal operation of the detector. The instrument pressure became too high, causing the entire analytical system to malfunction and preventing testing. Furthermore, to resolve this system malfunction, a significant amount of time and solvent was required to heat and flush the column and other components, incurring considerable time and cost. This further illustrates the importance and economic efficiency of using the device provided in this disclosure.

[0050] As can be seen from the results of Examples 1-2 and Comparative Examples 1-2, using the in-situ analysis apparatus and method provided in this disclosure, impurities in polymer samples are retained in the filtration assembly, and the filtered polymer sample solution is injected into the analyzer through the injector, thereby improving the analysis efficiency and accuracy, and reducing the impact on the chromatographic column and other components of the analyzer.

[0051] Example 3 Weigh 8.25 mg of a tablet-shaped polyethylene (PE) sample containing white inorganic impurities using a precision analytical balance (e.g., ...). Figure 5As shown in the image, the sample was wrapped in a 2400-mesh metal filter (3cm x 2cm) and fixed in a cylindrical metal sample chamber with an upper diameter of 0.85cm, a lower diameter of 0.68cm, and a height of 0.41cm. It was then placed in a 10mL sample vial with a concentration of 1mg / mL and dissolved at 160℃ for 120min. A CEF (Crystallization Eluent Fractionation) test was performed, and the CEF instrument status and test results were observed. After high-temperature dissolution, as shown... Figure 6 As shown in the figure, the specific results are shown in Table 2.

[0052] Example 4 This embodiment uses the same method as Embodiment 3, except that 8.01 mg of polyethylene (PE) sample was weighed in this embodiment, and the test results are shown in Table 1.

[0053] Table 2 CEF Test Results

[0054] As shown in Table 2, the recoveries of Examples 3 and 4 were not within the confidence interval (95-105%), indicating that the filtration component in the device provided in this disclosure successfully separated inorganic impurities and polymers. Impurities were trapped within the filtration component, while polymers in the solvent successfully passed through the filtration component, entered the flow channel via the injector, and were then tested through the tubing, column, and detector of the CEF instrument. The testing process had no impact on the instrument components. In contrast, the comparative examples did not use a filtration component, and the samples could not be directly analyzed by CEF. Impurities in the samples could be inorganic or other organic substances insoluble in trichlorobenzene solvent, existing in the solution as particulates or other suspended matter. Direct entry into the chromatograph could easily cause column blockage, affecting the normal operation of the valve rotor and detector, and in severe cases, leading to the paralysis of the entire analytical system. The method provided in this disclosure eliminates the need for manual offline filtration, successfully preventing impurities from entering the chromatograph, eliminating errors caused by manual filtration, and improving the accuracy and precision of the analytical results.

[0055] This method is suitable for polymer analysis and testing instruments, is simple to operate, saves solvents and time, and has great economic benefits.

[0056] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0057] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. An in-situ analysis device for polymer samples containing impurities, characterized in that, The device includes a filter assembly, sample vials, a sample injector, and an analyzer; The sample vial is used to place and / or fix the filter assembly and to contain the solvent used to dissolve the polymer sample; The sample vial is equipped with a sample inlet. One end of the sample injector is connected to the sample inlet, and the other end of the sample injector is connected to the analyzer, so that the polymer sample solution dissolved and filtered in the sample vial is injected into the analyzer for analysis.

2. The apparatus according to claim 1, wherein, The filtration assembly includes a filter screen and / or a sample chamber; the filter screen is used to enclose and / or block the filtration of the polymer sample; the sample chamber is used to fix the filter screen.

3. The apparatus according to claim 2, wherein, The filter screen has 2-10 layers, preferably 3-7 layers, and more preferably 3-5 layers; the mesh size is 400-3000 mesh, preferably 2000-2500 mesh.

4. The apparatus according to claim 2, wherein, The filter assembly is an embedded filter assembly and / or an external filter assembly; The embedded filter component is a filter screen. The polymer sample is added to the sample bottle, and the filter screen is embedded inside the sample bottle, so that the polymer sample is placed between the inner side of the sample bottle and the outer side of the filter screen. Solvent is added to the sample bottle and comes into contact with the polymer sample to be tested, so that the dissolved polymer sample enters the filter screen and is then injected into the analyzer through the sampler. Alternatively, the external filter assembly includes a filter screen and a sample chamber; after the polymer sample is wrapped in the filter screen, the filter screen is fixed in the sample chamber, the sample chamber is placed in a sample bottle, the polymer sample dissolves in the sample bottle, and the sample is injected into the analyzer through the injector.

5. The apparatus according to claim 4, wherein, The position of the filter component is not higher than the sampling port.

6. The apparatus according to claim 1, wherein, The filter component is selected from any one of metal filter components, polymer filter components and inorganic filter components, and does not react with the polymer sample and solvent.

7. The apparatus according to claim 1, wherein, The analyzer includes at least one of the following: a high-temperature gel permeation chromatograph, a crystallization elution and fractionation instrument, a xylene soluble matter analyzer, a polymer intrinsic viscosity analyzer, and a temperature gradient interaction chromatograph.

8. An in-situ analytical method for polymer samples containing impurities, characterized in that, The method uses the apparatus of any one of claims 1-7 and includes the following steps: The polymer sample to be tested is encapsulated in a filter assembly, allowing the polymer sample to dissolve in the solvent in the sample vial and then filtered through the filter assembly. The filtered polymer solution is then injected into the analyzer for analysis via a sample injector.

9. The method according to claim 8, wherein, The polymer sample to be tested includes polyolefins; The polymer sample to be tested is a granular, powdered, or strip-shaped solid with a particle size not smaller than the pore size corresponding to the mesh size of the filter screen.

10. The method according to claim 9, wherein, The solvent includes at least one of chlorobenzene, dichlorobenzene, and trichlorobenzene; The dissolution conditions include: a temperature of 60-200℃, a time of 20-1000 min, a shaking frequency of 10-1000 rpm, and a concentration of the polymer sample to be tested of 0.1-10 mg / mL.

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