HG/T 2797.2-1996 Determination of iodine absorption value of silicon aluminum carbon black
Some standard content:
HG / T 2797. 2—1996
This standard is a method standard, which is equivalent to the international standard ISO1304:1985 "Rubber compounding agent-Determination of iodine absorption value of carbon black-Titration method"
The main technical differences between this standard and ISO1304-1985 are: This standard stipulates the use of mercuric iodide as a preservative, while the international standard ISO1304-1985 stipulates n-pentanol, which has been proved to be effective in practice. ISO1304 stipulates three sample weights. This standard only uses one sample weight of 0.5g, because the absorption value of silicon aluminum carbon is below 135mg/g. This standard was proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China; this standard is under the jurisdiction of the Carbon Black Industry Research and Design Institute of the Ministry of Chemical Industry; this standard was drafted by the Carbon Black Industry Research and Design Institute of the Ministry of Chemical Industry; the main drafters of this standard are Yu Lian and Hu Kaibi, 13
ISO (International Organization for Standardization) is a joint organization of national standard groups (ISO member groups) in the world. The work of formulating international standards is usually carried out by ISO technical committees. Any member group interested in a certain profession of the established technical committee has the right to participate in the committee. International organizations, whether governmental or non-governmental, that have a connection with ISO can also participate in this work. Before the international standard is adopted by the ISO Council, the technical committee will send the draft international standard to each member group for voting. According to ISO requirements, at least 75% of the member groups vote in favor of the standard, and it can be formally adopted. International Standard 1SO1304 was developed by ISO/TC45 Rubber and Rubber Products Technical Committee. The first edition of IS01304 was released in 1974. This edition is the second edition with a small modification to the first edition, replacing and canceling the first edition.
1 Scope
Chemical Industry Standard of the People's Republic of China
Determination of iodine absorption of silicon aluminum carbon black
This standard specifies the determination method of iodine absorption value of silicon aluminum carbon black. This standard is applicable to the determination of iodine absorption value of various types of silicon aluminum carbon black. 2 Reference Standards
HG / T 2797. 2 1996
cqv IS0 1304: 1985
The following standards contain provisions that constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid: All standards will be revised. Parties using this standard should explore the possibility of using the latest versions of the following standards: GB/T6682-92 Specifications and test methods for water used in analytical laboratories (cqvISO3696:1987) HG/T2797.7-1996 Determination of heating reduction of silicon aluminum carbon black H G/T2796-1996 Silicon aluminum carbon hot packaging, transportation, sampling and acceptance method, 3 Principle
Dry the silicon aluminum carbon black sample, weigh it, and mix it vigorously with a certain volume of standard iodine solution, then centrifuge the mixture, take a certain volume of the clear iodine solution after separation, titrate it with standard sodium thiosulfate solution, and calculate the iodine absorption value of silicon aluminum carbon black according to the titrated volume and sample mass,
4 Reagents
4.1 Sulfuric acid: density 1.84, analytical grade.
4.2 Sodium thiosulfate: analytical grade.
4.3 Potassium iodate: high grade,
4.4 Iodine: analytical grade.
4.5 Mercuric iodide: analytical grade,
4.6 Potassium iodide: analytical grade
4.7 Soluble starch: analytical grade.
4.8 Laboratory water specifications: meet the requirements of GB/T6682 grade 3 water. 5 Apparatus
5.1 Analytical balance: accurate to 0.1mg-
5.2 Drying oven: can be controlled at 105±2℃ or 125±1℃5.3 Mechanical shaker: 240r/min.
5.4 Centrifuge: speed above 1000r/min. 5.5 Pipette: 20 cm2, 25 cm, 50 cm*, Class A, 5 6 Burette: 25 cm, 50 cm, Class A. 5.7 Single-scale container bottle with stopper: 1000 cm2 Approved by the Ministry of Chemical Industry of the People's Republic of China on April 10, 1996 and implemented on January 1, 1997
HG /T 2797.2-1996
5.8 Erlenmeyer flask with stopper: 125 cm, 150 cm2, 250 cm2 5.9 Brown glass bottle with stopper: 1000 cm2
5.10 Explosion hopper: short neck, Φ75 mm,
5.11 Centrifuge tube: stoppered capacity 50 cm
5.12 Beaker: 50 cm2.
513 Dryer,
6 Solution preparation and calibration
61 Powder indicator: 2.5g/dm2
Weigh 2.5g powdered soluble starch and 2mg mercuric iodide, put them in a 50cm beaker, add 25cm water, stir well, immediately pour the starch/mercuric iodide suspension into 1dm boiling distilled water, stir at the same time, boil for not less than 10min to ensure full dissolution, cool it to room temperature, pour the upper clear solution into a stoppered glass bottle, 6.2 Potassium iodate/iodine Potassium iodide standard solution: c(1/6KI0,)=0.03941mol/dm6.2. Dry an appropriate amount of potassium iodate at 125±1℃ (5.2) for 1h, transfer to a desiccator and cool to room temperature. 6.2.2 In a 1000cm volumetric flask, dissolve 45g potassium iodide in about 200cm of water, then add 1.4058g of freshly dried potassium iodate (6.2.1) (weighed to 0.0001g), and when completely dissolved, dilute with water to .1000cm26.3 Sodium thiosulfate solution: c(Na25,0,)=0. 039 41 mo1 / dml,6.3.1 Preparation
Weigh 9.79 g (accurate to 0.005 g) of sodium thiosulfate (NazS20, 5H,0) containing 5 crystal waters, dissolve it in a 1000 cm2 dissolving bottle with about 500 cm2 of distilled water, add 5 cm2 of n-pentanol 1 or 0.01 g of sulfonated mercury and dilute it to 1000 cm2 with water, shake the solution in the bottle vigorously to ensure uniform dilution,6.3.2 Standardization
After standing for 24 h, standardize the sodium thiosulfate solution (6.3) with potassium iodate/potassium iodide solution (6.2), follow the steps below:
a) Accurately pipette 25 cm2 of potassium iodate/potassium iodide (6.2) into a 250 cm2 conical flask. Add 3 cm2 of about 20% (m/m) sulfuric acid solution to free iodine. Titrate the sodium thiosulfate solution. When it turns light yellow, add about 5 cm2 of starch solution (6.1) and continue titrating until the end point is reached when one drop of sodium thiosulfate solution changes from blue to colorless. The burette reading should be accurate to 0.01c3. Calculate the concentration of the sodium thiosulfate solution according to formula (1): cb)
25 × 0.039 41
Wherein: V,-volume of sodium thiosulfate solution consumed in titration, cm2 Note: Concentration factor is 25/V, and can be adjusted to 1 if necessary. CO.6.4 Iodine standard solution: c(1/2I,)=0.04728mol/dm(1)
6.4.1 Preparation
Weigh 57.00g potassium iodide (accurate to 0.01g), and transfer it to a 1000cm2 single-scale volumetric flask, add about 30cm2 of distilled water to dissolve it, and quickly weigh 6.01g iodine (accurate to 0.005.g). Quickly transfer to the above volumetric flask and slowly dilute with distilled water to 000 cml
6.4.2 Calibration
Instructions:
1) 1SO1304 uses Zhengmao, and domestic iodine is used instead of Zhengchengjiang for anti-magic purposes. 16
#20 7 3 2797, 3 333
After the above prepared iodine solution is left for 24 hours, use the standardized sodium thiosulfate solution to calibrate the iodine solution (6.4). Follow the steps below:
Use a pipette to accurately draw 25 cm of the specially standardized iodine solution and transfer it to a 250 cm Erlenmeyer flask. Use the above standardized sodium thiosulfate solution (6.3) to titrate the iodine solution in the Erlenmeyer flask. When the yellow color of iodine is close to disappearing, add about 1 cm of starch solution (6.1) and continue titrating until the blue color disappears. Calculate the concentration of the iodine solution according to formula (2): c,
Where: V-
-the volume of sodium thiosulfate solution consumed in titration, cm\;-the solubility of sodium thiosulfate in mol/dm\(2)
When the turbidity of the prepared iodine solution is higher than the required concentration, the volume of distilled water to be added to adjust to the required concentration can be determined according to formula (3)
The volume of the iodine solution before adjustment, cm\;Where:
-the concentration of the iodine solution before adjustment in mol/dm
cs---the specified concentration of the iodine solution (0.04728mol/dm\).Add a certain amount of distilled water calculated by formula (3) into the iodine solution, plug the bottle tightly, and shake to ensure uniform dilution. Note: Before calibration, the volume of the solution taken out from the iodine solution reservoir should be measured, from which the remaining iodine solution volume can be known. 2. The iodine solution should be calibrated to ±0.00005mol/dm, and the concentration should be within the range of 0.04723~0.04733mol/dm. 3. All reagents should be stored in brown bottles and placed in a dark place before use. 7 Test conditions
The test is best conducted in a laboratory with a temperature of 23±2°C and a relative humidity of 50±5% or a temperature of 27±2°C and a relative humidity of 65±5%.
It is recommended that the reagents and instruments used should be kept at the same room temperature and balanced for at least several hours before use. In the laboratory, there should be no smoke or steam that may affect the test results. 8 Sampling
8.1 Follow Chapter 5 of HG/T 2796 9 Sample preparation
9.1 Dry an appropriate amount of silicon aluminum carbon black test sample in a constant temperature drying oven at 105±2°C for 1 hour according to HG/T2797.7, take it out and place it in a desiccator to cool to room temperature. Before starting the test, the dried sample should be placed in a desiccator. 10 Steps
10.1 Take 0.5g of the above dried sample (weighed to 0.1mg) and place it in a clean centrifuge bottle. Plug the stopper immediately. 10.2 Use a pipette to accurately draw 25 mL of iodine solution, add it to the centrifuge tube containing the sample, plug the bottle tightly, and shake it on an oscillator. Instructions:
2) This standard only selects 0.5 g sample weight: ISO1304 stipulates that the sample weight is determined according to the iodine absorption value. 17
HG/T 2797.2 - 1996
10.3 After shaking, immediately centrifuge at a speed of 1 000 r/min. The speed reaches 1 000 r/m and the time is set. The centrifugation time is 3 min3)
10.4 After centrifugation, take out the centrifuge tube smoothly from the centrifuge and immediately transfer all the iodine into a 50 cm small beaker. The sample remains at the bottom of the centrifuge tube. Immediately use a pipette to accurately draw 20 cm2 of the separated clear iodine solution and weigh it into a 150 cm conical flask. Without disturbing the sample, 20 cm of iodine solution can also be directly drawn from the centrifuge tube. 10.5 Immediately titrate with sodium thiosulfate solution. When the solution turns light yellow, add about 5 cm of starch indicator and continue titrating until the blue color turns to colorless, which is the end point. Read the full-scale tube reading, accurate to 0.01cm10.6At the same time, perform a blank test,
11. Result expressionbZxz.net
11.1 The iodine absorption value I of the sample is expressed as the number of m of iodine adsorbed by each silicon aluminum carbon black, and is calculated according to the following formula (4): I μ (V, - V,) × 126. 9 el
158. 6 (V
Wherein: V is the volume of sodium thiosulfate solution used to titrate the blank iodine solution, cm\Vs--the volume of sodium thiosulfate solution consumed in titrating the sample iodine solution. cm;ci
-the concentration of sodium thiosulfate solution, mo)/dm': the mass disk of the sample, name.
When the mass of silicon aluminum carbon black sample is 0.5g, the formula is simplified to I = (V, - V,) × 12. 5 × concentration coefficient The concentration coefficient in formula (5) (see the note in 6.3.2) is calculated by taking the integer,
11.2 Allowable difference
The difference between two measurement results shall not exceed 2m/g12 Test report
The test report shall include the following items:
The standard number on which this test is based;
The type and mark of the sample:
Test results;
Test conditions:
Test date.
Instructions for use:
3) ISot304 stipulates centrifugation for 1 min and 3 min. This standard uses centrifugation for 3 min.18
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