Detection method and system based on analysis of thermo-oxidative aging resistance of anti-aging agent and computer program

Abstract

The invention relates to the technical field of rubber performance detection, in particular to a detection method and system based on analysis of thermo-oxidative aging resistance of an anti-aging agent and a computer program. The method comprises the following steps: putting rubber samples containing different anti-aging agents into a thermo-oxidative aging oven, and aging at 100 DEG C for 48-168 hours; cleaning and drying the aged sample by using an oil-soluble solvent and ethanol; the method comprises the following steps: cutting a sample into a specified size, and scanning in an XPS vacuum system; acquiring XPS data of the sample before and after aging by setting related test parameters; and processing the data by using peak splitting software, and calculating the sum of C-O / C = O peak areas so as to evaluate the thermo-oxidative aging resistance of the anti-aging agent. The method has the advantages of being high in detection speed, accurate and reliable in data, simple and convenient to operate, wide in application range and the like, can effectively assist in optimization of the anti-aging agent formula of the rubber product, and improves the durability and the performance stability of the product.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber performance detection, and in particular to a detection method, system and computer program based on analyzing the thermal oxygen aging resistance of an antioxidant. Background Art

[0002] In actual application, rubber materials are often exposed to various adverse environmental factors, such as high temperature, oxygen, ozone and ultraviolet rays. These environmental factors can cause the breakage or cross-linking of rubber molecular chains, resulting in a significant decrease in the physical properties of rubber products, such as strength, elasticity and fatigue resistance, and then cause aging. Rubber aging not only shortens the service life of rubber products, but also increases the cost of maintenance and replacement, seriously affecting its wide application in industries such as industry and transportation.

[0003] In order to delay the aging process of rubber, the rubber manufacturing industry usually adds antioxidants to rubber compositions. Antioxidants effectively block or slow down the chain growth process of rubber aging reactions by capturing free radicals and decomposing peroxides, thereby improving the durability and stability of rubber products. Specifically, antioxidants can maintain the physical properties of rubber products during long-term use, enhance their resistance to environmental factors such as ultraviolet rays and ozone, improve wear resistance and resistance to mechanical damage, and ensure that tires maintain good driving performance under various road conditions.

[0004] In the tire manufacturing industry, commonly used antioxidants include 2,2,4-trimethyl-1,2-dihydroquinoline polymer (TMQ), N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and microcrystalline wax. Due to their different chemical structures and protection mechanisms, these antioxidants show their respective advantages in terms of resistance to heat and oxygen aging, resistance to ozone aging and physical protection. However, the existing methods for testing the resistance to heat and oxygen aging of antioxidants often have problems such as slow detection speed, insufficient data accuracy and reliability, and it is difficult to meet the needs of rapid screening and optimization of antioxidant formulations.

[0005] In response to the above problems, there is an urgent need for a detection method that can quickly, accurately and reliably analyze the thermal oxidative aging resistance of antioxidants, so as to optimize the selection and use of antioxidants in the research and development and production of rubber products and improve the overall performance and service life of rubber products. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a detection method based on analyzing the heat-oxidative aging resistance of antioxidants. This method realizes a rapid and accurate evaluation of the heat-oxidative aging resistance of antioxidants in rubber compositions through systematic sample processing, XPS scanning and data analysis steps.

[0007] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: A detection method based on analyzing the thermal oxygen aging resistance of an antioxidant, characterized in that it comprises the following steps: S1, putting rubber samples containing different antioxidants into a thermal oxygen aging chamber and subjecting them to aging treatment at 95-105°C for 48 to 168 hours; S2, cleaning the oil stains on the surface of the aged rubber sample; S3, samples cut from the aged rubber samples; S4, placing the cut rubber sample on a sample stage of a vacuum system of an X-ray photoelectron spectrometer (XPS); S5, setting the XPS test related parameters, and positioning and calibrating the sample; S6, using XPS to scan the rubber samples before and after aging, the data acquisition times were 80-150 times, and the scanning binding energy range was 1.190 eV to 1.246 eV; S7, the scanning data was processed by peak separation software XPSPEAK41, and the CO / C=O peak area of ​​the rubber sample before and after aging was obtained by integration, and the CO(N 老化后 / N 老化前 ) and C=O(N 老化后 / N 老化前 ) peak area to evaluate the thermal oxygen aging resistance, CO (N 老化后 / N 老化前 ) and C=O(N 老化后 / N 老化前 ) The larger the sum of the peak areas, the worse the thermal oxygen aging resistance.

[0008] Preferably, the aging condition in step S1 is at 100° C. and the aging time ranges from 48 hours to 168 hours.

[0009] Preferably, an oil-soluble solvent is used in step S2, and the organic solvent is subsequently washed with ethanol and dried.

[0010] Preferably, the oil-soluble solvent is selected from cyclohexane and acetone.

[0011] Preferably, the rubber sample in step S3 is cut to a size of 0.5 cm×0.8 cm and a thickness of less than 4 mm.

[0012] Preferably, the XPS test related parameters in step S5 include a monochromatized AlKa X-ray source, an emission current, an anode voltage, an energy analyzer, a step length and an analysis area. The X-ray source of the X-ray photoelectron spectrometer uses an aluminum monochromator, the emission current is set to 10 mA, and the anode voltage is 15 kV; the energy analyzer is 80 eV, the energy range of the wide spectrum scan is 0 to 1200 eV, and the step length is 1 eV / step.

[0013] Furthermore, the present invention also provides a system for analyzing the thermal oxygen aging resistance of an antioxidant, the system implementing the method described, comprising: A thermal oxygen aging chamber, used to age rubber samples under set temperature and time conditions; a cleaning device, comprising an oil-soluble solvent supply system and an ethanol cleaning system for cleaning the surface of the rubber sample; a cutting device for cutting the aged rubber sample into specimens of specified size; An X-ray photoelectron spectrometer (XPS), including a sample stage, a monochromatized AlKa X-ray source, an energy analyzer, and a data acquisition system; A data processing unit is used to run the peak separation software XPSPEAK41 to perform peak separation and peak area calculation on the scanning data.

[0014] Furthermore, the present invention also provides application of the method in screening antioxidants in rubber formulations.

[0015] Furthermore, the present invention also provides a computer-readable storage medium on which a computer program or instruction is stored. When the computer program or instruction is executed by a processor, step S7 in the method is implemented.

[0016] Furthermore, the present invention also provides a computer program product, including a computer program or instructions, which implements step S7 in the method when executed by a processor.

[0017] The present invention adopts the above technical solution, and provides a method for detecting the thermal oxygen aging resistance of antioxidants based on X-ray photoelectron spectrometer (XPS). Through systematic sample processing, XPS scanning and data analysis steps, a rapid and accurate evaluation of the thermal oxygen aging resistance of antioxidants in rubber compositions is achieved. The specific technical effects are as follows: 1. Fast detection speed: This method can complete the aging, processing and analysis of samples in a relatively short time through standardized aging treatment and XPS scanning steps, greatly improving the efficiency of antioxidant performance detection.

[0018] 2. Accurate and reliable data: XPS technology is used to accurately scan rubber samples before and after aging, and the peak separation software XPSPEAK41 is used for data processing to ensure accurate measurement of the CO / C=O peak area, thereby providing a reliable evaluation index for thermal oxygen aging resistance.

[0019] 3. Easy operation: The steps of this method are clear, and the required equipment and reagents are easy to obtain. It is suitable for routine laboratory operations in rubber manufacturing companies and research institutions, reducing the technical threshold and operation difficulty.

[0020] 4. Strong quantitative analysis capability: By calculating the sum of the peak areas of CO (after aging / before aging) and C=O (after aging / before aging), it can quantitatively reflect the effect of antioxidants on the thermal oxygen aging resistance of rubber, which is convenient for performance comparison and optimization between different antioxidants.

[0021] 5. Wide scope of application: This method is applicable to various rubber compositions containing different types of antioxidants. It is not only suitable for the field of tire manufacturing, but can also be promoted to the aging performance detection of other rubber products, and has broad application prospects.

[0022] 6. Improve product quality and durability: By quickly and accurately screening and optimizing the antioxidant formula, the aging resistance of rubber products can be significantly improved, their service life can be extended, maintenance and replacement costs can be reduced, and the market competitiveness of products can be enhanced.

[0023] In summary, the method for detecting the heat-oxidative aging resistance of antioxidants provided by the present invention not only solves the problems of low detection efficiency and inaccurate and unreliable data in the prior art, but also provides an efficient and accurate technical means for the research and development and production of rubber products, which has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 , Figure 2 This is the O1s curve diagram of Example 1 before and after aging.

[0025] Figure 3 , Figure 4 This is the O1s curve diagram of Example 2 before and after aging.

[0026] Figure 5 , Figure 6 This is the O1s curve diagram of Example 3 before and after aging.

[0027] Figure 7 , Figure 8 This is the O1s curve diagram of Example 4 before and after aging.

[0028] Fig. 9 , Fig.10This is the O1s curve diagram of Comparative Example 1 before and after aging. DETAILED DESCRIPTION

[0029] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] 1. Preparation of tread rubber composition As shown in Table 1, each component was weighed according to the formula ratio (phr), and the tread rubber composition was prepared by the following mixing method: (1) Mixing stage: Use an internal mixer to pre-mix natural rubber (Vietnam 3L), carbon black N234, stearic acid, N234 antioxidant, softening oil, zinc oxide, microcrystalline wax and other chemical additives (excluding sulfur and accelerators). The mixing time is controlled between 150 and 230 seconds, and the discharge temperature is maintained between 145°C and 155°C to obtain a masterbatch.

[0031] (2) Final mixing stage: Add the masterbatch, 10% S sulfur, accelerator NS and selected antioxidants (such as 6PPD, TMQ, etc.) into the internal mixer for final mixing. The mixing time is controlled between 60 and 180 seconds, and the discharge temperature is maintained between 95°C and 105°C to finally obtain the tread rubber composition.

[0032] The formula of Example 1 is shown in Table 1. The formulas of Examples 2-4 are similar to Example 1, but the types and contents of the antioxidants are different, as shown in Table 1.

[0033] Table 1: Specific examples and comparative examples Tread rubber composition (phr) Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Natural rubber (Vietnam 3L) 100.0 100.0 100.0 100.0 100.0 Zinc Oxide 5.0 5.0 5.0 5.0 5.0 Stearic acid 3.0 3.0 3.0 3.0 3.0 N234 45.0 45.0 45.0 45.0 45.0 6PPD 1.5 3.0 RD 3.0 Microcrystalline wax 3.0 Softening oil 6.0 6.0 6.0 6.0 6.0 10%S 2.1 2.1 2.1 2.1 2.1 NS 1.0 1.0 1.0 1.0 1.0 The sources of the raw materials in Table 1 are as follows: NR: Vietnam 3L; Carbon black N234: Product of Shanghai Cabot Chemical Co., Ltd. Softening oil: Hansheng Petrochemical Co., Ltd. Zinc oxide: Product of Shijiazhuang Zhiyi Zinc Industry Co., Ltd. Stearic acid: Product of Baili Sdn Bhd (Malaysia) Microcrystalline wax: Product of Shandong Yanggu Huatai Chemical Co., Ltd. Antioxidant 6PPD: Product of Sinopec Nanjing Chemical Industry Co., Ltd. Antioxidant TMQ: Product of Kemai Chemical Co., Ltd. Accelerator NS: Product of Kemai Chemical Co., Ltd. 10%S sulfur: product of Jiangxi Jianbo Rubber Additive Co., Ltd.

[0034] 2. Physical properties test of tread rubber composition According to the general method of national standard, the physical properties of the prepared tread rubber composition are tested. Specific test items include tensile product (TB*EB) and tensile product retention rate.

[0035] 3. Testing of antioxidant's resistance to heat and oxygen aging The detection method of the present invention is used to analyze the heat-oxidative aging resistance of the antioxidants in each embodiment, and the specific steps are as follows: Step S1: Aging treatment Rubber samples containing different antioxidants (Examples 1-4 and Comparative Example 1) were prepared according to the formula, placed in a thermal oxidative aging box, and subjected to thermal oxidative aging treatment at 100° C. for 120 hours.

[0036] Step S2: Sample cleaning After the aging treatment is completed, the rubber sample is taken out and the oil stains on the surface of the rubber sample are cleaned with an oil-soluble solvent (such as cyclohexane or acetone). Subsequently, the organic solvent residue is further cleaned with ethanol, and the sample is dried.

[0037] Step S3: Sample cutting The cleaned and dried rubber samples were cut into samples with an area of ​​0.5 cm × 0.8 cm and a thickness of less than 4 mm to ensure the consistency of the sample size for subsequent testing.

[0038] Step S4: XPS sample preparation Place the cut rubber sample on the sample stage of the vacuum system of the X-ray photoelectron spectrometer (XPS) to ensure that the sample surface is flat and fixed.

[0039] Step S5: XPS test parameter setting Set the relevant parameters of the XPS test, including using a monochromatized AlKa X-ray source, adjusting the emission current and anode voltage, selecting a suitable energy analyzer and step size, and setting the analysis area. At the same time, the sample is precisely positioned and calibrated to ensure the accuracy of the test data.

[0040] Step S6: XPS Scan XPS scans were performed on the rubber samples before and after aging. Each sample was scanned 100 times, and the scanning binding energy range was set from 1.190 eV to 1.246 eV to obtain high-resolution photoelectron spectrum data.

[0041] Step S7: Data analysis The XPS data obtained by scanning were processed by peak separation software XPSPEAK41, and the areas of CO and C=O peaks were obtained by integration. The thermal oxygen aging resistance of the antioxidant was evaluated by calculating the sum of the peak areas of CO (after aging / before aging) and C=O (after aging / before aging). The larger the sum of the peak areas, the worse the thermal oxygen aging resistance.

[0042] 4. Data Analysis and Results Evaluation According to the test data in Table 2 and Table 3, combined with the tensile product retention rate and the CO / C=O peak integral area after XPS detection, the thermal oxygen aging resistance of each embodiment can be comprehensively evaluated, and the data after peak separation processing are plotted using origin software. The results are as follows Figure 1-Figure 10 For example, the tensile product retention rate of Example 3 is 43.5%, and the peak area sum after XPS detection is 1.79, showing its excellent aging resistance.

[0043] Table 2: Physical properties before and after aging Aging conditions: 100℃×48h Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Tensile product before aging (TB*EB) 13808 12623 14077 12077 12802 Tensile product after aging (TB*EB) 3761 4680 6089 5251 4820 Tensile strength retention rate (%) 27.2 37.1 43.3 43.5 37.7 Table 3: Data analysis after XPS detection Comparative Example 1 Example 1 Example 2 Example 3 Example 4 <![CDATA[C-O(N 老化后 / N 老化前 )Integral area]]> 14.70 8.33 2.83 0.79 5.63 <![CDATA[C=O(N 老化后 / N 老化前 )Integral area]]> 3.75 5.20 2.91 1.00 4.23 Integral area and 18.45 13.53 5.74 1.79 9.86 By comparing the tensile product retention rate with the CO / C=O peak integral area after XPS detection, it can be seen that Example 3 has better aging resistance.

[0044] From the perspective of molecular structure and theory, antioxidant 6PPD performs better in flex crack resistance and dynamic aging, and is suitable for rubber products used under dynamic conditions. Antioxidant TMQ has good comprehensive performance in resistance to thermal oxidative aging and ozone aging. Microcrystalline wax has the main advantage of physical protection. The rubber samples in the examples and comparative examples were subjected to static thermal oxidative aging at 100°C for 48 hours, and the main focus was on the thermal oxidative aging resistance of the rubber. Relatively speaking, the aging resistance of Example 3 is better.

[0045] The above is a description of the embodiments of the present invention. Through the above description of the disclosed embodiments, professionals and technicians in the field can implement or use the present invention. Various modifications to these embodiments will be apparent to professionals and technicians in the field. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will conform to the widest range consistent with the principles and novelties disclosed herein.

Claims

1. A detection method based on analyzing the thermal oxygen aging resistance of antioxidants, characterized in that: The following steps are involved: S1, putting rubber samples containing different antioxidants into a thermal oxygen aging chamber and subjecting them to aging treatment at 95-105°C for 48 to 168 hours; S2, cleaning the oil stains on the surface of the aged rubber sample; S3, samples cut from the aged rubber samples; S4, placing the cut rubber sample on a sample stage of a vacuum system of an X-ray photoelectron spectrometer (XPS); S5, setting the XPS test related parameters, and positioning and calibrating the sample; S6, using XPS to scan the rubber samples before and after aging, the data acquisition times were 80-150 times, and the scanning binding energy range was 1.190 eV to 1.246 eV; S7, the scanning data was processed by peak separation software XPSPEAK41, and the CO / C=O peak area of ​​the rubber sample before and after aging was obtained by integration, and the CO(N 老化后 / N 老化前 ) and C=O(N 老化后 / N 老化前 ) peak area to evaluate the thermal oxygen aging resistance, CO (N 老化后 / N 老化前 ) and C=O(N 老化后 / N 老化前 ) The larger the sum of the peak areas, the worse the thermal oxygen aging resistance.

2. The method according to claim 1, characterized in that The aging condition in step S1 is at 100° C. and the aging time ranges from 48 hours to 168 hours.

3. The method according to claim 1, characterized in that In step S2, an oil-soluble solvent is used, and then the organic solvent is washed with ethanol and dried.

4. The method according to claim 3, characterized in that: The oil-soluble solvent is selected from cyclohexane and acetone.

5. The method according to claim 1, characterized in that The rubber sample cut in step S3 has an area of ​​0.5 cm×0.8 cm and a thickness of less than 4 mm.

6. The method according to claim 1, characterized in that The XPS test related parameters in step S5 include monochromatized AlKa X-ray source, emission current, anode voltage, energy analyzer, step size and analysis area. The X-ray source of the X-ray photoelectron spectrometer uses an aluminum monochromator, the emission current is set to 10 mA, and the anode voltage is 15 kV; the energy analyzer is 80 eV, the energy range of the wide spectrum scan is 0-1200 eV, and the step size is 1 eV / step.

7. A system for analyzing the thermal oxygen aging resistance of an antioxidant, the system implementing the method according to any one of claims 1 to 6, comprising: A thermal oxygen aging chamber, used to age rubber samples under set temperature and time conditions; a cleaning device, comprising an oil-soluble solvent supply system and an ethanol cleaning system for cleaning the surface of the rubber sample; a cutting device for cutting the aged rubber sample into specimens of specified size; An X-ray photoelectron spectrometer (XPS), including a sample stage, a monochromatized AlKa X-ray source, an energy analyzer, and a data acquisition system; A data processing unit is used to run the peak separation software XPSPEAK41 to perform peak separation and peak area calculation on the scanning data.

8. Use of the method according to any one of claims 1 to 6 in screening antioxidants in rubber formulations.

9. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instruction is executed by a processor, step S7 in the method according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, step S7 in the method according to any one of claims 1 to 6 is implemented.

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