Method for screening softening oil for waterproof asphalt based on thermogravimetric analysis

Abstract

The invention belongs to the field of chemical detection, and particularly relates to a method for screening softening oil for waterproof asphalt based on thermogravimetric analysis, which comprises the following steps: a) placing a softening oil sample in a sample cabin of a thermal analyzer, adjusting the temperature range of the thermal analyzer, setting the heating rate and the atmosphere of nitrogen, and starting the thermal analyzer to obtain a DTG curve of the softening oil sample; b) based on the DTG curve, extracting the initial weight loss temperature, the maximum weight loss rate corresponding temperature and the final weight loss temperature of the softening oil sample; and c) according to the initial weight loss temperature, the maximum weight loss rate corresponding temperature and the final weight loss temperature of the softening oil sample, judging whether the softening oil sample is used as the softening oil of the waterproof asphalt or not. The method is based on a thermogravimetric analysis technology, and softening oil capable of being used for waterproof asphalt can be rapidly screened.

Description

Technical Field

[0001] The invention belongs to the field of chemical detection, and in particular relates to a method for screening softening oil for waterproof asphalt based on thermogravimetric analysis. Background Art

[0002] In the field of construction and engineering, the application of waterproof asphalt is crucial, and its performance is directly related to the quality and durability of waterproof projects. However, to ensure that waterproof asphalt has reliable waterproof performance, strict testing and screening of its raw materials are indispensable. The raw materials of waterproof membranes generally include waterproof asphalt, fillers, etc., and the raw materials of waterproof asphalt are composed of base asphalt and softening oil. Therefore, it is crucial to select high-quality softening oil to improve the performance of waterproof membranes.

[0003] At present, there is a lack of screening methods for softening oil for waterproof asphalt. It mainly relies on experience, testing kinematic viscosity indicators or testing performance after blending into waterproof asphalt. This has increased the workload in disguise. In the long run, it has a certain restrictive effect on the development of waterproof asphalt technology. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a method for screening softening oil for waterproof asphalt based on thermogravimetric analysis. The method is based on thermogravimetric analysis technology and can quickly screen softening oil that can be used for waterproof asphalt.

[0005] The present invention provides a method for screening softening oil for waterproof asphalt based on thermogravimetric analysis, comprising the following steps:

[0006] a) placing the softened oil sample in the sample chamber of the thermal analyzer, adjusting the temperature range of the thermal analyzer, setting the heating rate, setting the atmosphere to nitrogen, starting the thermal analyzer, and obtaining the DTG curve of the softened oil sample;

[0007] b) extracting the starting weight loss temperature, the temperature corresponding to the maximum weight loss rate and the ending weight loss temperature of the softened oil sample based on the DTG curve;

[0008] c) judging whether the softening oil sample can be used as a softening oil for waterproof asphalt according to the initial weight loss temperature, the temperature corresponding to the maximum weight loss rate and the final weight loss temperature of the softening oil sample.

[0009] Preferably, in step a), the softened oil sample is one or more of petroleum series softened oil, fatty oil series softened oil and pine oil series softened oil.

[0010] Preferably, in step a), the starting temperature of the temperature range is ≥30°C and the ending temperature is ≤900°C.

[0011] Preferably, in step a), the starting temperature of the temperature range is 30-50°C, and the ending temperature is 550-900°C.

[0012] Preferably, in step a), the heating rate is 5 to 20° C. / min.

[0013] Preferably, in step c), the judgment principle includes: if the initial weight loss temperature of the softening oil sample is 100-200°C, the temperature corresponding to the maximum weight loss rate is 250-500°C, and the terminal weight loss temperature is 500-900°C, then it can be used as a softening oil for waterproof asphalt.

[0014] Preferably, in step a), the softening oil samples are multiple; in step b), the data extracted based on the DTG curve also includes the half-peak width of the DTG curve of the softening oil sample; in step c), the judgment principle also includes: selecting the softening oil with the largest half-peak width of the DTG curve from the softening oil samples that meet the requirements of the starting weight loss temperature, the temperature corresponding to the maximum weight loss rate and the ending weight loss temperature as the softening oil for waterproof asphalt.

[0015] Compared with the prior art, the present invention provides a method for screening softening oil for waterproof asphalt based on thermogravimetric analysis, comprising the following steps: a) placing a softening oil sample in a sample cabin of a thermal analyzer, adjusting the temperature range of the thermal analyzer, setting the heating rate, using nitrogen as the atmosphere, starting the thermal analyzer, and obtaining a DTG curve of the softening oil sample; b) extracting the initial weight loss temperature, the temperature corresponding to the maximum weight loss rate, and the end weight loss temperature of the softening oil sample based on the DTG curve; c) judging whether it is used as a softening oil for waterproof asphalt according to the initial weight loss temperature, the temperature corresponding to the maximum weight loss rate, and the end weight loss temperature of the softening oil sample. The present invention is based on the principle that the thermal weight loss situation can reflect the strength and stability of the molecular bonds of the softening oil, and uses a thermal analyzer to test the softening oil, and evaluates whether it is suitable for use as a softening oil for waterproof asphalt through the thermal weight loss data obtained by the test. The method provided by the present invention can quickly screen softening oil that can be used for waterproof asphalt, reducing the workload of screening experiments for softening oil for waterproof asphalt. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0017] Figure 1 This is a thermogravimetric detection data diagram provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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.

[0019] The present invention provides a method for screening softening oil for waterproof asphalt based on thermogravimetric analysis, comprising the following steps:

[0020] a) placing the softened oil sample in the sample chamber of the thermal analyzer, adjusting the temperature range of the thermal analyzer, setting the heating rate, setting the atmosphere to nitrogen, starting the thermal analyzer, and obtaining the DTG curve of the softened oil sample;

[0021] b) extracting the starting weight loss temperature, the temperature corresponding to the maximum weight loss rate and the ending weight loss temperature of the softened oil sample based on the DTG curve;

[0022] c) judging whether the softening oil sample can be used as a softening oil for waterproof asphalt according to the initial weight loss temperature, the temperature corresponding to the maximum weight loss rate and the final weight loss temperature of the softening oil sample.

[0023] In the present invention, in step a), the softened oil sample is preferably one or more of petroleum series softened oil, fatty oil series softened oil and pine oil series softened oil, specifically one or more of gasoline, diesel, waste engine oil, wax oil and vegetable oil.

[0024] In the present invention, in step a), the starting temperature of the temperature range is preferably ≥30°C, more preferably 30-50°C, specifically 30°C, 35°C, 40°C, 45°C or 50°C; the ending temperature of the temperature range is preferably ≤900°C, more preferably 550-900°C, specifically 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C or 900°C.

[0025] In the present invention, in step a), the heating rate is preferably 5 to 20°C / min, specifically 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, 11°C / min, 12°C / min, 13°C / min, 14°C / min, 15°C / min, 16°C / min, 17°C / min, 18°C / min, 19°C / min or 20°C / min.

[0026] In the present invention, in step a), the DTG curve is also called a microentropy thermogravimetric curve.

[0027] In the present invention, in step b), the data extracted based on the DTG curve preferably also includes the half-peak width of the DTG curve of the softened oil sample; the calculation method of the half-peak width of the DTG curve is T1-T0, wherein T1 is the temperature corresponding to the maximum weight loss rate, and T0 is the starting weight loss temperature.

[0028] In the present invention, in step c), the higher the initial weight loss temperature is, the better the thermal stability and the higher the molecular energy barrier of the softened oil are; the higher the temperature corresponding to the maximum weight loss rate is, the stronger the intramolecular or intermolecular interaction of the softened oil is, and the more resilient it is; the wider the half-peak width of the DTG curve is, the stronger the force of the intermolecular or intramolecular bonds of the softened oil is, the more overlapping decomposition stages are, and the better the low-temperature crack resistance and high-temperature stability are.

[0029] In the present invention, in step c), the judgment principle specifically includes: if the initial weight loss temperature of the softening oil sample is 100-200°C, the temperature corresponding to the maximum weight loss rate is 250-500°C, and the terminal weight loss temperature is 500-900°C, then it can be used as a softening oil for waterproof asphalt.

[0030] In the present invention, when there are multiple softening oil samples in step a), the judgment principle of step c) preferably also includes: selecting the softening oil with the largest half-peak width of the DTG curve from the softening oil samples that meet the requirements of the initial weight loss temperature, the temperature corresponding to the maximum weight loss rate and the terminal weight loss temperature as the softening oil for waterproof asphalt.

[0031] The invention is based on the principle that the thermal weight loss can reflect the strength and stability of the molecular bonds of the softening oil. The softening oil is tested by a thermal analyzer, and the thermal weight loss data obtained by the test is used to evaluate whether it is suitable for use as a softening oil for waterproof asphalt. The method provided by the invention can quickly screen softening oil that can be used for waterproof asphalt, reducing the workload of the screening experiment of softening oil for waterproof asphalt.

[0032] For the purpose of greater clarity, the present invention is described in detail with reference to the following examples and comparative examples.

[0033] Example 1

[0034] (1) Five types of softened oils were selected, namely gasoline, diesel, waste engine oil, wax oil and grease-3 (vegetable oil).

[0035] (2) The above softened oils were subjected to thermal gravimetric tests. The specific process was as follows: the softened oil samples were placed in the sample chamber of the thermal analyzer, the temperature range of the thermal analyzer was adjusted to 40-600°C, the heating rate was set to 10°C / min, the atmosphere was nitrogen, the thermal analyzer was started, and the DTG curve of the softened oil sample was obtained (such as Figure 1 shown).

[0036] (3) Based on Figure 1 It can be seen that:

[0037] (3.1) Wax oil, waste oil, and grease have an initial weight loss temperature in the range of 100-200°C, a maximum weight loss rate corresponding to a temperature in the range of 250-500°C, and an end weight loss temperature in the range of 500-900°C. They can be used as softening oil for waterproof asphalt;

[0038] (3.2) The initial weight loss temperature of gasoline and diesel is lower than 100°C, so they are not suitable for use as softening oil for waterproof asphalt;

[0039] (3.3) By comparing the half-width of the DTG curves of wax oil, waste oil and Grease-3, it can be seen that Grease-3 has the largest half-width, so Grease-3 is the most preferred waterproof asphalt softening oil.

[0040] Comparative Example 1

[0041] The base asphalt 70# was selected and blended with gasoline, diesel, waste engine oil, wax oil and grease-3 in the same proportion at the same temperature. The test results are shown in Table 1.

[0042] Table 1 Waterproof asphalt index

[0043]

[0044] It can be seen from Table 1 that the flash point of waterproof asphalt blended with gasoline or diesel is unqualified, so gasoline and diesel cannot be used as softening oil for waterproof asphalt; wax oil, waste engine oil and Grease-3 can all be used as softening oil for waterproof asphalt, and the comprehensive index of waterproof asphalt blended with Grease-3 is better, which is consistent with the analysis results of Example 1.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for screening softening oil for waterproof asphalt based on thermogravimetric analysis, characterized in that: The following steps are involved: a) placing the softened oil sample in the sample chamber of the thermal analyzer, adjusting the temperature range of the thermal analyzer, setting the heating rate, setting the atmosphere to nitrogen, starting the thermal analyzer, and obtaining the DTG curve of the softened oil sample; b) extracting the starting weight loss temperature, the temperature corresponding to the maximum weight loss rate and the ending weight loss temperature of the softened oil sample based on the DTG curve; c) judging whether the softening oil sample can be used as a softening oil for waterproof asphalt according to the initial weight loss temperature, the temperature corresponding to the maximum weight loss rate and the final weight loss temperature of the softening oil sample.

2. The method according to claim 1, characterized in that In step a), the softened oil sample is one or more of petroleum series softened oil, fatty oil series softened oil and pine oil series softened oil.

3. The method according to claim 1, characterized in that In step a), the starting temperature of the temperature range is ≥30°C and the ending temperature is ≤900°C.

4. The method according to claim 3, characterized in that In step a), the starting temperature of the temperature range is 30-50°C, and the ending temperature is 550-900°C.

5. The method according to claim 1, characterized in that In step a), the heating rate is 5 to 20° C. / min.

6. The method according to claim 1, characterized in that In step c), the principles of judgment include: If the initial weight loss temperature of the softening oil sample is 100-200°C, the temperature corresponding to the maximum weight loss rate is 250-500°C, and the termination weight loss temperature is 500-900°C, it can be used as a softening oil for waterproof asphalt.

7. The method according to claim 6, characterized in that In step a), the softened oil samples are multiple; In step b), the data extracted based on the DTG curve also includes the half-peak width of the DTG curve of the softened oil sample; In step c), the judgment principle also includes: selecting the softening oil with the largest half-peak width of the DTG curve from the softening oil samples that meet the requirements of the initial weight loss temperature, the temperature corresponding to the maximum weight loss rate and the terminal weight loss temperature as the softening oil for waterproof asphalt.

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