Methods for determining the oil absorption value of solid materials

Abstract

A method for determining the oil absorption value of solid materials belongs to the technical field of solid material adsorption performance testing. The method includes the following steps: S1, mixing an oil agent and the solid material to be tested uniformly to obtain a mixture; S2, performing nuclear magnetic resonance (NMR) testing on the mixture obtained in step S1 to obtain relaxation time spectra of the adsorbed oil agent and the free oil agent; S3, comparing the peak areas of the adsorbed oil agent and the free oil agent in the relaxation time spectra to obtain the oil absorption value of the solid material to be tested. The testing method provided by this invention has good reproducibility and can reduce testing errors.

Description

Technical Field

[0001] This invention relates to a technique for testing the adsorption properties of solid materials, specifically a method for determining the oil absorption value of solid materials. Background Technology

[0002] The oil absorption value of existing solid materials is generally determined using the following method: Vegetable oil (usually linseed oil) is slowly added to 100 grams of powder while stirring, until the powder can be formed into a large clump of loose particles. The amount of oil consumed is measured in grams. The oil absorption value is related to the porosity between powder particles, the surface properties of the particles, and the specific surface area of ​​the powder. When the particles are aggregated, the porosity between them is larger, and the oil absorption value of the powder will increase. The hydrophilic and oleophilic properties of the particle surface have a significant impact on the oil absorption value. Higher oleophilicity results in a higher oil absorption value. The surface energy and charge distribution of the particles affect particle aggregation and also influence the oil absorption value. The larger the specific surface area of ​​the particles, the higher the oil absorption value. Therefore, the finer the powder, the higher the oil absorption value. In addition, GB / T3780.2-2007 Carbon Black Part 2: Determination of Oil Absorption Value (National Standard) specifies the method for determining the oil absorption value of carbon black, and TS 2583-1977 Pigments General Test Methods Part 5: Determination of Oil Absorption Value (Industry Standard) specifies the method for determining the oil absorption value of pigments.

[0003] The advantages of the above method for testing the oil absorption value of solid materials are low measurement cost, but the test endpoint requires manual judgment, resulting in large errors, poor reproducibility, long time consumption, and significant influence from human factors, which restricts the assurance and improvement of product quality and the high-quality development of enterprises.

[0004] The present invention is made to address the aforementioned problems existing in the prior art. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, this invention proposes a method for determining the oil absorption value of solid materials, which offers good reproducibility and reduces testing errors.

[0006] This invention includes the following steps:

[0007] S1, mix the oil and the solid material to be tested evenly to obtain a mixture;

[0008] S2, perform nuclear magnetic resonance testing on the mixture obtained in step S1 to obtain relaxation time spectra of adsorbed oil and free oil.

[0009] S3. By comparing the peak areas of adsorbed oil and free oil in the relaxation time spectrum, the oil absorption value of the solid material to be tested can be obtained.

[0010] In step S1, the solid material to be tested can be either an inorganic powder material or an organic powder material.

[0011] In step S1, the oil can be a natural organic oil or a synthetic organic oil, such as turpentine oil or linseed oil, or dibutyl phthalate.

[0012] Preferably, the mass ratio of oil to solid material is 0.01 to 1000.

[0013] In step S2, the relaxation time spectra of the adsorbed oil agent and the free oil agent include at least one of the following: T1 relaxation time spectrum, T2 relaxation time spectrum, and T1-T2 relaxation time spectrum.

[0014] In step S3, the formula for calculating the oil absorption value of the solid material to be tested is as follows:

[0015] D = 100 * K * As / (As + Af),

[0016] In the formula, D is the oil absorption value, which represents the mass of the oil adsorbent in 100g of solid material, in g; K is the mass ratio of oil to solid material, dimensionless; As is the integral area corresponding to the peak of the adsorbed oil in the relaxation time spectrum, dimensionless; Af is the integral area corresponding to the peak of the free oil in the relaxation time spectrum, dimensionless.

[0017] Technical effect

[0018] Compared with the prior art, the present invention has the following technical effects:

[0019] 1) It can quickly measure the oil absorption value of solid materials, is easy to operate, and can greatly save testing time;

[0020] 2) The results are highly accurate and reproducible, completely avoiding the deviations caused by human error in national and industry standards. Attached Figure Description

[0021] Figure 1 The T2 relaxation time spectrum of the carbon black material and dibutyl phthalate mixture in Example 1;

[0022] Figure 2 The T1 relaxation time spectrum is the mixture of zirconium oxide material and turpentine oil in Example 2. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Experimental methods not specified in the embodiments were performed according to conventional methods and conditions.

[0024] Example 1

[0025] This embodiment provides a method (NMR method) for determining the oil absorption value of carbon black. The specific operation steps are as follows:

[0026] (1) Weigh 5g of carbon black, then add 3g of dibutyl phthalate and mix thoroughly.

[0027] (2) The mixture was placed in an NMR spectrometer to test the T2 relaxation time spectrum, such as... Figure 1 As shown, the T2 relaxation time peak area of ​​the adsorbed dibutyl phthalate oil was 523.4, and the T2 relaxation time peak area of ​​the free dibutyl phthalate oil was 1669.7.

[0028] (3) Calculate the oil absorption value of the carbon black D = 100 * 3 / 5 * 523.4 / (523.4 + 1669.7) = 14.3.

[0029] Example 2

[0030] This embodiment provides a method (NMR method) for determining the oil absorption value of zirconia powder. The specific operation steps are as follows:

[0031] (1) Weigh 5g of zirconium oxide powder, then add 5g of turpentine oil and mix thoroughly.

[0032] (2) The mixture was placed in an NMR spectrometer to test the T1 relaxation time spectrum, such as... Figure 2 As shown, the peak area of ​​the T1 relaxation time of adsorbed turpentine oil was 887.1, and the peak area of ​​the T1 relaxation time of free turpentine oil was 2472.5.

[0033] (3) Calculate the oil absorption value D of the zirconia powder: D = 100 * 5 / 5 * 887.1 / (887.1 + 2472.5) = 26.4.

[0034] Results Comparison

[0035] According to GB / T3780.2-2007 Carbon Black Part 2: Determination of Oil Absorption Value (National Standard), the oil absorption value of the carbon black in Example 1 was determined. The specific test method was as follows: the weighed sample was transferred into the mixing tank of the oil absorption meter, the lid was closed, the carbon black oil absorption meter was started, the instrument started to run and oil was dripped. When the added oil made the semi-plastic carbon black sample reach the pre-adjusted torque level, the oil absorption meter and titrator were automatically turned off. The volume of oil consumed was the oil absorption value of the carbon black material. The results are shown in Table 1.

[0036] The oil absorption value of the zirconia powder in Example 2 was determined according to TS 2583-1977 General Test Methods for Pigments - Part 5: Determination of Oil Absorption Value (industry standard). The specific test method was as follows: Turpentine was added dropwise to 100g of zirconia material, mixing continuously with a spatula. With the continuous addition of turpentine, it was best to bind all the zirconia together into a spherical shape. If more turpentine was added, the system would become thinner. The amount of turpentine used at this point is the oil absorption value of the zirconia powder. The results are shown in Table 1.

[0037] Table 1 Oil Absorption Value Test Results

[0038]

[0039] As shown in Table 1, the standard deviation and relative standard deviation of the national standard and industry standard are relatively large, and the reproducibility of the test is poor. However, the standard deviation and relative standard deviation of the test method of the present invention are relatively small, and the reproducibility is better. It can save a lot of test time and is therefore superior to the national standard and industry standard.

[0040] It should be emphasized that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for determining the oil absorption value of a solid material, characterized in that, Includes the following steps: S1, mix the oil and the solid material to be tested evenly to obtain a mixture; S2, perform nuclear magnetic resonance testing on the mixture obtained in step S1 to obtain relaxation time spectra of adsorbed oil and free oil. S3. Compare the peak areas of adsorbed oil agent and free oil agent in the relaxation time spectrum to obtain the oil absorption value of the solid material to be tested. The formula for calculating the oil absorption value of the solid material to be tested is as follows: D = 100 × K × As / (As + Af) In the formula, D is the oil absorption value, which represents the mass of the oil adsorbent in 100g of solid material, in g; K is the mass ratio of oil to solid material, dimensionless; As is the integral area corresponding to the peak of the adsorbed oil in the relaxation time spectrum, dimensionless; Af is the integral area corresponding to the peak of the free oil in the relaxation time spectrum, dimensionless.

2. The method for determining the oil absorption value of solid materials according to claim 1, characterized in that, In step S1, the solid material to be tested is either an inorganic powder or an organic powder.

3. The method for determining the oil absorption value of solid materials according to claim 1, characterized in that, In step S1, the oil agent is a natural organic oil agent or a synthetic organic oil agent.

4. The method for determining the oil absorption value of solid materials according to claim 1, characterized in that, The mass ratio of oil to solid material is 0.01 to 1000.

5. The method for determining the oil absorption value of solid materials according to claim 1, characterized in that, In step S2, the relaxation time spectra of the adsorbed oil agent and the free oil agent include at least one of the following: T1 relaxation time spectrum, T2 relaxation time spectrum, and T1-T2 relaxation time spectrum.

Images