Method and device for judging crystallization capacity of polypropylene resin

Abstract

The invention discloses a method and a device for judging the crystallization capacity of polypropylene resin. The method comprises the following steps: carrying out hot-pressing treatment on a polypropylene resin sample to form a transparent film; placing the transparent film in a temperature control environment for crystallization to obtain an observation sample; observing the observation sample in a transmission mode by using a polarizing microscope, and analyzing the spherocrystal diameter of the observation sample; and judging the crystallization capacity of the polypropylene resin according to the spherulitic crystal diameter of the observation sample. According to the method and the device for judging the crystallization capacity of the polypropylene resin, the crystallization capacity of the polypropylene resin can be judged within extremely short time (lt; the method has the advantages of short time consumption, low cost and high identification efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of characterization of polypropylene resin crystallization behavior, and in particular to a method and device for determining the crystallization ability of polypropylene resin. Background Art

[0002] Polypropylene (PP) is a semi-crystalline polymer with a high melting point, mechanical strength and insulation properties. It is widely used in packaging, textiles, medical devices, automotive industry, electronics and household products. The crystallization of polypropylene is a key factor in determining its processing and application performance. It is of great significance to design and synthesize polypropylene resins with high crystallinity and to be able to accurately and quickly characterize its crystallization behavior.

[0003] The traditional characterization of the crystallization behavior of polypropylene resin mainly focuses on crystallinity and crystal structure, and the methods used include differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Among them, the DSC method is a method of inferring the crystallization performance by measuring the thermal effect of the polymer during melting, which can intuitively reflect the crystallinity of the resin, but it is difficult to accurately characterize the changes during the crystal growth process; the XRD method is to achieve the characterization of the crystal form, grain size and other mesostructures through the principle of X-ray diffraction, and is the most comprehensive method for characterizing the crystal structure. However, for the growth changes of crystals during the crystallization process, the XRD method requires the use of more complex and larger synchrotron radiation equipment and in-situ observation equipment. The test cost is extremely high and very time-consuming, and it is not suitable for rapid verification of the basic structure of polypropylene resin in industrial production processes.

[0004] Although polarizing microscopy (POM) can directly observe the changes in crystal morphology based on the birefringence properties of polypropylene spherulites, the application of POM in the observation of polypropylene spherulites in some current literature reports is mainly focused on studying the crystal morphology of polypropylene resin under a certain specific state. For example, the paper "Crystallization morphology of partially melted isotactic polypropylene in static and flow fields" [J]. Polymer Materials Science and Engineering, 2022, 38(10): 98-102, used POM to study the crystal morphology of partially melted isotactic polypropylene in static and flow fields, and observed its morphology under different flow fields by isothermal crystallization for a certain period of time; the paper "Research on Crystallization Properties of Polypropylene" [J]. Engineering Plastics Application, 2015, 41(7): 5. DOI: 10.3969 / j.issn.1001-3539.2015.07.024, observed the changes in spherulite size and crystal nucleus density by isothermal crystallization for a certain period of time, and studied the differences in crystal morphology of different grades of polypropylene. The common feature of these studies is that they completed the observation of the final state of polypropylene resin after crystallization under certain conditions, but did not directly use POM to study and compare the crystallization rate and growth state of different resins under the same crystallization conditions. These studies only have scientific value and cannot guide production practice. Therefore, there is no research report on using POM to intuitively observe the crystallization rate and growth state of polypropylene resin, and quickly identify polypropylene resins with higher crystallization ability under the same crystallization conditions in different polypropylene resin samples, so as to adapt to production practice. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problems that the method for quickly identifying a polypropylene resin with high crystallinity among different polypropylene resin samples in the prior art is not intuitive and quick enough, and the use of large-scale equipment to characterize the crystallinity is costly, time-consuming and has low testing efficiency.

[0006] The purpose of the present invention is to adopt the following technical solutions to achieve:

[0007] The present invention provides a method for determining the crystallization ability of a polypropylene resin, comprising:

[0008] The polypropylene resin sample is subjected to heat pressing to form a transparent film;

[0009] Placing the transparent film in a temperature-controlled environment to crystallize to obtain an observation sample;

[0010] Observing the observation sample in transmission mode using a polarizing microscope, and analyzing the diameter of the spherulites of the observation sample;

[0011] The crystallization ability of the polypropylene resin is determined according to the spherulite diameter of the observed sample.

[0012] Preferably, the hot pressing temperature is 200-250° C., and the hot pressing time is 5-15 seconds.

[0013] Preferably, the mass of the polypropylene resin sample is 2-10 mg.

[0014] Preferably, the transparent film has a thickness of 3 to 10 μm.

[0015] Preferably, in the step of placing the transparent film in a temperature-controlled environment to crystallize and obtain an observation sample, the crystallization process includes:

[0016] The ambient temperature is adjusted to an initial temperature of 200-250°C, maintained at a constant temperature for 1-5 minutes, and then cooled at a cooling rate of 10-200 k / min.

[0017] Preferably, the crystallization process is carried out in a protective gas, and the protective gas is nitrogen.

[0018] Preferably, the flow rate of the nitrogen gas is 10 to 50 mL / min.

[0019] Preferably, observing the observation sample using a polarizing microscope in a transmission mode and analyzing the spherulite diameter of the observation sample comprises:

[0020] When the temperature is lowered to 80-130° C., an isothermal crystallization time range of 5-50 s is selected, and the spherulite growth morphology of the observed sample is observed in transmission mode using a polarizing microscope, and the spherulite diameter of the observed sample at the same temperature and the same time is analyzed using image recognition software.

[0021] Preferably, the determining the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample comprises:

[0022] The spherulite diameters of the observed samples were compared to determine that the sample with a larger average spherulite diameter had a stronger crystallization ability.

[0023] Preferably, the transmission magnification of the polarizing microscope is 50 to 200 times.

[0024] Preferably, the method for determining the crystallization ability of the polypropylene resin comprises:

[0025] The polypropylene resin sample is subjected to heat pressing to form a transparent film with a thickness of 3 to 10 μm;

[0026] The transparent film is placed in a temperature-controlled environment and the initial temperature is adjusted to 230-250° C. After maintaining the temperature for 1-3 minutes, the temperature is lowered at a rate of 50-200 k / min to obtain an observation sample by crystallization;

[0027] When the temperature is lowered to 100 to 130° C., an isothermal crystallization time range of 5 to 50 seconds is selected, the observation sample is observed in a transmission mode using a polarizing microscope, and the spherulite diameter of the observation sample is analyzed;

[0028] The crystallization ability of the polypropylene resin is determined according to the spherulite diameter of the observed sample.

[0029] Based on the same inventive concept, the present invention also provides a device for determining the crystallization ability of a polypropylene resin, the device comprising:

[0030] A pretreatment module, used for subjecting the polypropylene resin sample to a heat-pressing treatment to form a transparent film;

[0031] A temperature control module, used for placing the transparent film in a temperature-controlled environment to crystallize an observation sample;

[0032] A testing module, wherein the testing module comprises a polarizing microscope, and the polarizing microscope is used to observe the observed sample in a transmission mode, and to analyze the spherulite diameter of the observed sample;

[0033] The evaluation module is used to determine the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention provides a method and device for determining the crystallization ability of a polypropylene resin. The method comprises the following steps: making a polypropylene resin sample into a transparent film of a certain thickness, performing crystallization under a temperature-controlled environment, observing the spherulite growth morphology of each sample at a specific temperature and time using a polarizing microscope, and determining the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample. A spherulite with a larger diameter indicates a stronger crystallization ability. The formation of spherulites mainly depends on specific conditions and processes. Factors such as thickness, crystallization temperature and time will affect the morphology formation and growth rate of spherulites. If the crystallization is too fast and the spherulites grow rapidly and squeeze each other, the size of the spherulites cannot be distinguished. If the spherulites grow slowly and do not crystallize for a long time, they cannot be observed. The present invention controls the growth rate of spherulites by optimizing parameters such as thickness, crystallization temperature and time, and selects to observe through a polarizing microscope at a specific temperature. The spherulite morphology of each sample and the difference in the growth rate of spherulites of different polypropylene resins can be observed very intuitively and clearly, so that the polypropylene resin with high crystallinity can be determined by the size of the spherulites. The entire determination process takes less than 10 minutes. Compared with traditional test methods such as DSC and XRD that require complex test equipment and a long test procedure (>1h), the present invention can intuitively reflect the growth morphology of spherulites only through a polarizing microscope, and can determine the crystallization ability of the polypropylene resin in a very short time (<10min). It takes short time, low cost, and high recognition efficiency. It has important economic value for the synthesis, processing and application of polypropylene resins and is suitable for practical production guidance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention is a schematic flow chart of a method for determining the crystallization ability of a polypropylene resin;

[0037] Figure 2 It is a schematic structural diagram of a device for determining the crystallization ability of a polypropylene resin according to the present invention;

[0038] Figure 3 This is an observation diagram of the POM spherulite morphology of the polypropylene resin sample of Example 1;

[0039] Figure 4 This is an observation diagram of the POM spherulite morphology of the polypropylene resin sample of Example 2;

[0040] Figure 5 This is an observation diagram of the POM spherulite morphology of the polypropylene resin sample of Example 3;

[0041] Figure 6 This is an observation diagram of the POM spherulite morphology of the polypropylene resin sample of Example 4;

[0042] Among them, there are a pre-processing module 100, a temperature control module 200, a testing module 300, and an evaluation module 400. DETAILED DESCRIPTION

[0043] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, wherein the illustrative embodiments and descriptions are only used to explain the present invention but are not intended to limit the present invention.

[0044] Example 1

[0045] The present invention provides a method for determining the crystallization ability of a polypropylene resin, and the specific flow chart is as follows: Figure 1 As shown, the specific process is as follows:

[0046] S101: performing heat pressing on a polypropylene resin sample to form a transparent film;

[0047] S102: placing the transparent film in a temperature-controlled environment to crystallize to obtain an observation sample;

[0048] S103: observing the observation sample in a transmission mode using a polarizing microscope, and analyzing the diameter of the spherulites of the observation sample;

[0049] S104: Determine the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample.

[0050] In the above S101, the polypropylene resin sample is subjected to heat pressing to form a transparent film, specifically as follows: 10 mg of the polypropylene resin sample is placed on a glass slide, and heat pressed with a cover glass at 250° C. for 15 seconds to form a transparent film with a thickness of 10 μm;

[0051] In the above S102, the transparent film is placed in a temperature-controlled environment to crystallize to obtain an observation sample, specifically as follows: the transparent film sample is placed on a temperature-controlled hot stage, nitrogen is introduced, and the nitrogen flow rate is set to 50 ml / min, the temperature of the hot stage is raised to 250° C. and kept at a constant temperature for 1 min, and then the temperature is lowered to 130° C. at a cooling rate of 200 K / min;

[0052] In the above S103, the observation sample is observed in the transmission mode using a polarizing microscope, and the spherulite diameter of the observation sample is analyzed, specifically as follows: the spherulite growth morphology of each sample at 130° C. is observed in the transmission mode at 200 times using a polarizing microscope, and an observation image of the spherulite growth morphology after a crystallization time of 50 seconds is taken; the spherulite growth morphology observation image is analyzed and processed by image recognition software, and the average diameter of the spherulites of each different polypropylene resin sample in a random field of view is counted and calculated;

[0053] In the above S104, the crystallization ability of the polypropylene resin is determined according to the spherulite diameter of the observed sample, specifically as follows: the spherulite diameters of different polypropylene resin samples are compared, and the one with the larger average spherulite diameter is determined to have the highest crystallization ability.

[0054] Figure 3 : This is the POM spherulite morphology observation diagram of the polypropylene resin sample of this embodiment. Figure 3 As shown, after crystallization, polypropylene resin forms spherulites with clear size and close distribution. The size of the spherulites can be observed very intuitively. By analyzing the average diameter of the spherulites in the observation image through image recognition software, the crystallization ability of the polypropylene resin can be determined by the average diameter of the spherulites. The entire determination process only takes 3.5 minutes.

[0055] Example 2

[0056] The present invention provides a method for determining the crystallization ability of a polypropylene resin, and the specific process is as follows:

[0057] S101: performing heat pressing on a polypropylene resin sample to form a transparent film;

[0058] S102: placing the transparent film in a temperature-controlled environment to crystallize to obtain an observation sample;

[0059] S103: observing the observation sample in a transmission mode using a polarizing microscope, and analyzing the diameter of the spherulites of the observation sample;

[0060] S104: Determine the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample.

[0061] In the above S101, the polypropylene resin sample is subjected to heat pressing to form a transparent film, specifically as follows: 5 mg of the polypropylene resin sample is placed on a glass slide, and heat pressed with a cover glass at 230° C. for 10 seconds to form a transparent film with a thickness of 5 μm;

[0062] In the above S102, the transparent film is placed in a temperature-controlled environment to crystallize to obtain an observation sample, specifically as follows: the transparent film sample is placed on a temperature-controllable hot stage, nitrogen is introduced, and the nitrogen flow rate is set to 25 ml / min, the temperature of the hot stage is raised to 230° C. and kept constant for 3 minutes, and then the temperature is lowered to 100° C. at a cooling rate of 100 K / min;

[0063] In the above S103, the observation sample is observed in the transmission mode using a polarizing microscope, and the spherulite diameter of the observation sample is analyzed, specifically as follows: the spherulite growth morphology of each sample at 100° C. is observed in the transmission mode of 100 times using a polarizing microscope, and the spherulite growth morphology observation image after the crystallization time of 25 seconds is taken; the spherulite growth morphology observation image is analyzed and processed by image recognition software, and the average diameter of the spherulites of each different polypropylene resin sample in a random field of view is counted and calculated;

[0064] In the above S104, the crystallization ability of the polypropylene resin is determined according to the spherulite diameter of the observed sample, specifically as follows: the spherulite diameters of different polypropylene resin samples are compared, and the one with the larger average spherulite diameter is determined to have the highest crystallization ability.

[0065] Figure 4 : This is the POM spherulite morphology observation diagram of the polypropylene resin sample of this embodiment. Figure 4 As shown, after crystallization, polypropylene resin forms spherulites with clear size and close distribution. The size of the spherulites can be observed very intuitively. By analyzing the average diameter of the spherulites in the observation image through image recognition software, the crystallization ability of the polypropylene resin can be determined by the average diameter of the spherulites. The entire determination process only takes 5 minutes.

[0066] Example 3

[0067] The present invention provides a method for determining the crystallization ability of a polypropylene resin, and the specific process is as follows:

[0068] S101: performing heat pressing on a polypropylene resin sample to form a transparent film;

[0069] S102: placing the transparent film in a temperature-controlled environment to crystallize to obtain an observation sample;

[0070] S103: observing the observation sample in a transmission mode using a polarizing microscope, and analyzing the diameter of the spherulites of the observation sample;

[0071] S104: Determine the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample.

[0072] In the above S101, the polypropylene resin sample is subjected to heat pressing to form a transparent film, specifically as follows: 3 mg of the polypropylene resin sample is placed on a glass slide, and heat pressed with a cover glass at 230° C. for 5 seconds to form a transparent film with a thickness of 3 μm;

[0073] In the above S102, the transparent film is placed in a temperature-controlled environment to crystallize to obtain an observation sample, specifically as follows: the transparent film sample is placed on a temperature-controlled hot stage, nitrogen is introduced, and the nitrogen flow rate is set to 50 ml / min, the temperature of the hot stage is raised to 230° C. and kept constant for 2 minutes, and then the temperature is lowered to 120° C. at a cooling rate of 100 K / min;

[0074] In the above S103, the observation sample is observed in the transmission mode using a polarizing microscope, and the spherulite diameter of the observation sample is analyzed, specifically as follows: the spherulite growth morphology of each polypropylene resin sample at 120° C. is observed in the transmission mode at 50 times using a polarizing microscope, and an observation image of the spherulite growth morphology after a crystallization time of 10 seconds is taken; the spherulite growth morphology observation image is analyzed and processed by image recognition software, and the average diameter of the spherulites of each different polypropylene resin sample in a random field of view is counted and calculated;

[0075] In the above S104, the crystallization ability of the polypropylene resin is determined according to the spherulite diameter of the observed sample, specifically as follows: the spherulite diameters of different polypropylene resin samples are compared, and the one with the larger average spherulite diameter is determined to have the highest crystallization ability.

[0076] Figure 5 : This is the POM spherulite morphology observation diagram of the polypropylene resin sample of this embodiment. Figure 5 As shown, after crystallization, polypropylene resin forms spherulites with clear size and close distribution. The size of the spherulites can be observed very intuitively. By analyzing the average diameter of the spherulites in the observation image through image recognition software, the crystallization ability of the polypropylene resin can be determined by the average diameter of the spherulites. The entire determination process only takes 4.5 minutes.

[0077] Example 4

[0078] The present invention provides a method for determining the crystallization ability of a polypropylene resin, and the specific process is as follows:

[0079] S101: performing heat pressing on a polypropylene resin sample to form a transparent film;

[0080] S102: placing the transparent film in a temperature-controlled environment to crystallize to obtain an observation sample;

[0081] S103: observing the observation sample in a transmission mode using a polarizing microscope, and analyzing the diameter of the spherulites of the observation sample;

[0082] S104: Determine the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample.

[0083] In the above S101, the polypropylene resin sample is subjected to heat pressing to form a transparent film, specifically as follows: 4 mg of the polypropylene resin sample is placed on a glass slide, and heat pressed with a cover glass at 250° C. for 5 seconds to form a transparent film with a thickness of 3 μm;

[0084] In the above S102, the transparent film is placed in a temperature-controlled environment to crystallize to obtain an observation sample, specifically as follows: the transparent film sample is placed on a temperature-controllable hot stage, nitrogen is introduced, and the nitrogen flow rate is set to 50 ml / min, the temperature of the hot stage is raised to 230° C. and kept at this temperature for 1 minute, and then the temperature is lowered to 130° C. at a cooling rate of 50 K / min;

[0085] In the above S103, the observation sample is observed in the transmission mode using a polarizing microscope, and the spherulite diameter of the observation sample is analyzed, specifically as follows: the spherulite growth morphology of each sample at 130° C. is observed in the transmission mode of 50 times using a polarizing microscope, and an observation image of the spherulite growth morphology after a crystallization time of 5 seconds is taken; the spherulite growth morphology observation image is analyzed and processed by image recognition software, and the average diameter of the spherulites of each different polypropylene resin sample in a random field of view is counted and calculated;

[0086] In the above S104, the crystallization ability of the polypropylene resin is determined according to the spherulite diameter of the observed sample, specifically as follows: the spherulite diameters of different polypropylene resin samples are compared, and the one with the larger average spherulite diameter is determined to have the highest crystallization ability.

[0087] Figure 6 : This is the POM spherulite morphology observation diagram of the polypropylene resin sample of this embodiment. Figure 6 As shown, after crystallization, polypropylene resin forms spherulites with clear size and close distribution. The size of the spherulites can be observed very intuitively. By analyzing the average diameter of the spherulites in the observation image through image recognition software, the crystallization ability of the polypropylene resin can be determined by the average diameter of the spherulites. The entire determination process only takes 3 minutes.

[0088] Example 5

[0089] The present invention provides a method for determining the crystallization ability of a polypropylene resin, and the specific process is as follows:

[0090] S101: performing heat pressing on a polypropylene resin sample to form a transparent film;

[0091] S102: placing the transparent film in a temperature-controlled environment to crystallize to obtain an observation sample;

[0092] S103: observing the observation sample in a transmission mode using a polarizing microscope, and analyzing the diameter of the spherulites of the observation sample;

[0093] S104: Determine the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample.

[0094] In the above S101, the polypropylene resin sample is subjected to heat pressing to form a transparent film, specifically as follows: 2 mg of the polypropylene resin sample is placed on a glass slide, and heat pressed with a cover glass at 200° C. for 5 seconds to form a transparent film with a thickness of 3 μm;

[0095] In the above S102, the transparent film is placed in a temperature-controlled environment to crystallize to obtain an observation sample, specifically as follows: the transparent film sample is placed on a temperature-controlled hot stage, nitrogen is introduced, and the nitrogen flow rate is set to 10 ml / min, the temperature of the hot stage is raised to 200° C. and kept constant for 1 min, and then the temperature is lowered to 80° C. at a cooling rate of 15 K / min;

[0096] In the above S103, the observation sample is observed in the transmission mode using a polarizing microscope, and the spherulite diameter of the observation sample is analyzed, specifically as follows: the spherulite growth morphology of each sample at 80° C. is observed in the transmission mode at 50 times using a polarizing microscope, and an observation image of the spherulite growth morphology after a crystallization time of 5 seconds is taken; the spherulite growth morphology observation image is analyzed and processed by image recognition software, and the average diameter of the spherulites of each different polypropylene resin sample in a random field of view is counted and calculated;

[0097] In the above S104, the crystallization ability of the polypropylene resin is determined according to the spherulite diameter of the observed sample, specifically as follows: the spherulite diameters of different polypropylene resin samples are compared, and the one with the larger average spherulite diameter is determined to have the highest crystallization ability.

[0098] After the polypropylene resin is crystallized, the sample is observed through a polarizing microscope after isothermal crystallization at 80°C for 5 seconds. Spherulites with clear sizes and close distribution can be clearly observed. The average diameter of the spherulites in the observation image is analyzed by image recognition software. The crystallization ability of the polypropylene resin can be determined by the average diameter of the spherulites. The whole determination process only takes 10 minutes.

[0099] Example 6

[0100] Based on the same inventive concept, the present invention provides a device for determining the crystallization ability of polypropylene resin, such as Figure 2 As shown, it includes a pre-processing module 100, a temperature control module 200, a testing module 300 and an evaluation module 400. The functions of the above modules are described in detail below:

[0101] The pretreatment module 100 is used to heat-press the polypropylene resin sample to form a transparent film;

[0102] A temperature control module 200, used to place the transparent film in a temperature-controlled environment to crystallize an observation sample;

[0103] A testing module 300, wherein the testing module 300 comprises a polarizing microscope, and the polarizing microscope is used to observe the observed sample in a transmission mode, and analyze the spherulite diameter of the observed sample;

[0104] The evaluation module 400 is used to determine the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample.

[0105] In the temperature control module 200, the temperature control during the crystallization process is specifically as follows: the ambient temperature is adjusted to an initial temperature of 200-250°C, and then cooled after being kept constant for 1-5 minutes, with a cooling rate of 10-200 k / min.

[0106] In the above-mentioned test module 300, the process of crystallization observation using a polarizing microscope is specifically as follows: after cooling through the above-mentioned temperature control module 200, when the temperature is lowered to 80-130°C, an isothermal crystallization time range of 5-50s is selected, and the spherulite growth morphology of the observed sample is observed in the transmission mode using a polarizing microscope, and the spherulite diameter of the observed sample at the same temperature and the same time is analyzed using image recognition software.

[0107] In the evaluation module 400, the evaluation process is specifically as follows: comparing the spherulite diameters of the observed samples, and determining that the sample with a larger average spherulite diameter has a stronger crystallization ability.

[0108] Compared with traditional testing methods such as DSC and XRD, which require complex testing equipment and a long testing procedure (>1h), the present invention can intuitively reflect the growth morphology of spherulites only through a polarizing microscope, and can judge the crystallization ability of polypropylene resin in a very short time (<12min), with short time consumption, low cost and high identification efficiency. It has important economic value for the synthesis, processing and application of polypropylene resin and is suitable for practical production guidance.

[0109] For the convenience of description, the various parts of the above-mentioned device are divided into various modules or units according to their functions and described separately. Of course, when implementing the present application, the functions of each module or unit can be implemented in the same or multiple software or hardware.

[0110] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0111] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0112] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0113] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0114] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A method for determining the crystallization ability of a polypropylene resin, characterized in that: include: The polypropylene resin sample is subjected to heat pressing to form a transparent film; Placing the transparent film in a temperature-controlled environment to crystallize to obtain an observation sample; Observing the observation sample in transmission mode using a polarizing microscope, and analyzing the diameter of the spherulites of the observation sample; The crystallization ability of the polypropylene resin is determined according to the spherulite diameter of the observed sample.

2. The method according to claim 1, characterized in that The hot pressing temperature is 200-250° C., and the hot pressing time is 5-15 seconds.

3. The method according to claim 1, characterized in that: The mass of the polypropylene resin sample is 2-10 mg.

4. The method according to claim 1, characterized in that: The thickness of the transparent film is 3-10 μm.

5. The method according to claim 1, characterized in that In the step of placing the transparent film in a temperature-controlled environment to crystallize and obtain an observation sample, the crystallization process includes: The ambient temperature is adjusted to an initial temperature of 200-250°C, maintained at a constant temperature for 1-5 minutes, and then cooled at a cooling rate of 10-200 k / min.

6. The method according to claim 5, characterized in that The crystallization process is carried out in a protective gas, and the protective gas is nitrogen.

7. The method according to claim 6, characterized in that The flow rate of the nitrogen gas is 10 to 50 mL / min.

8. The method according to claim 5, characterized in that The step of observing the observation sample in a transmission mode using a polarizing microscope and analyzing the spherulite diameter of the observation sample comprises: When the temperature is lowered to 80-130° C., an isothermal crystallization time range of 5-50 s is selected, and the spherulite growth morphology of the observed sample is observed in transmission mode using a polarizing microscope, and the spherulite diameter of the observed sample at the same temperature and the same time is analyzed using image recognition software.

9. The method according to claim 8, characterized in that The step of determining the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample comprises: The spherulite diameters of the observed samples were compared to determine that the sample with a larger average spherulite diameter had a stronger crystallization ability.

10. The method according to claim 8, characterized in that The transmission magnification of the polarizing microscope is 50 to 200 times.

11. The method according to claim 1, characterized in that: include: The polypropylene resin sample is subjected to heat pressing to form a transparent film with a thickness of 3 to 10 μm; The transparent film is placed in a temperature-controlled environment and the initial temperature is adjusted to 230-250° C. After maintaining the temperature for 1-3 minutes, the temperature is lowered at a rate of 50-200 k / min to obtain an observation sample by crystallization; When the temperature is lowered to 100 to 130° C., an isothermal crystallization time range of 5 to 50 seconds is selected, the observation sample is observed in a transmission mode using a polarizing microscope, and the spherulite diameter of the observation sample is analyzed; The crystallization ability of the polypropylene resin is determined according to the spherulite diameter of the observed sample.

12. A device for determining the crystallization ability of polypropylene resin, characterized in that: include: A pretreatment module, used for subjecting the polypropylene resin sample to a heat-pressing treatment to form a transparent film; A temperature control module, used for placing the transparent film in a temperature-controlled environment to crystallize an observation sample; A testing module, wherein the testing module comprises a polarizing microscope, and the polarizing microscope is used to observe the observed sample in a transmission mode, and to analyze the spherulite diameter of the observed sample; The evaluation module is used to determine the crystallization ability of the polypropylene resin according to the spherulite diameter of the observed sample.

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