GB/T 3780.1-1998 Test method for iodine absorption value of carbon black for rubber
Some standard content:
GB/T 3780.1—1998
This standard is the test method standard for carbon black products for rubber. It is a revision of GB/3780.101 test method for carbon black iodine absorption value for rubber according to the American Society for Testing and Materials standard ASTMD1510-9i. The standard is equivalent to ASTM11510-96.
The main differences between this standard and ASTM131510:96 are as follows: In Appendix A, potassium dichromate standard solution is marked; ASTMD1510 stipulates that potassium iodide-sulfuric acid mixture should be colorless, and yellow should be removed. This standard stipulates that if the iodine arsenic trioxide mixed solution appears light yellow, it should be tested; if it appears dark yellow, it should be discarded and the standard solution should be prepared with arsenic trioxide standard solution: ASTM D1:10 stipulates: arsenic trioxide solution should be used directly; according to the actual situation, this standard stipulates that the arsenic trioxide solution should be added to dissolve the arsenic trioxide into a arsenic trioxide solution. The main differences of this standard GI/T3780.1--91: Repeatability 0.? g/kg revised to 1.? g/kg, reproducibility revised from 2.6 g/kg to 3.4 g/kg: Appendix A, when calibrating with ammonia dihydrogen standard solution: add a step of dissolving solid arsenic trioxide into a arsenic trioxide solution. This standard replaces GB/T3780.191 from the time of implementation. Appendix A of the technical standard is the appendix of the standard, and this standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is issued by the National Technical Committee for Standardization of Rubber and Rubber Products, Carbon Black Technical Committee. Drafting unit of this standard: Carbon Black Industry Research and Design Institute of the Ministry of Chemical Industry: Main drafters of this standard: Xue, Shi Jing III, Hu Kai. This standard was first issued in June 1983 and revised for the second time in April 1991. National Standard of the People's Republic of China
Test method for iodine adsorption value of carbon black in rubber products.
Carbon black in rubber products.--Test methed for iodine adsorption value GB/T 3780. 1--1998
Retained in place of G3 761 1
The iodine adsorption value can effectively characterize the surface area of furnace carbon black. Under normal circumstances, the iodine absorption value of carbon black is related to its surface area. The surface voids, volatile matter and solvent extracts of carbon black have a certain influence on the iodine absorption value. 1 Scope || tt || This standard specifies the test method for iodine absorption of carbon black for rubber. This standard is applicable to all types of rubber black (excluding S series, mixed gas and natural gas tank carbon black). 2 Reference standards || tt || The provisions contained in the following standards constitute non-standard provisions through reference in this standard. The version shown in the standard is still valid at the time of publication. All standards will be revised, and parties using this standard should explore the possibility of using the latest version of the following standards. GB 3778-94 Carbon black
GB/16682-92 Laboratory water standard test method (91503656:1587) B8170.87 numerical revision
3 Method summary
Use the specified concentration of iodine standard solution to soak the carbon black sample and make it fully soaked. When the absorption reaches the equilibrium, use sodium iodide standard titration solution to titrate the iodine. The ratio of the adsorbed iodine salt to the carbon black sample is the iodine absorption value. 4 Reagents and materials
All reagents are analytically pure. Water is hot water or water of equivalent purity. It should meet the requirements of (iT3/T6582). 4.1 n-pentanol.
4.2 Mercuric iodide.
4.3 Mercuric oxide: high purity,
Potassium iodide solution, 111g/dm, preparation see Appendix A4.5 Sulfuric acid solution: 10% (u/), preparation see Appendix A4.6 Potassium dichromate standard solution; (1/6KCr.),) = 0.039 4 mol/dm*, preparation see Appendix A4.7
Sulfuric acid solution: c(1/2H,SO,) = 1 r30l/dm*, preparation see Appendix A4.8
4.9 Potassium iodate-potassium iodide base solution: c(1/sKI),) -0.039 4 mal/drm. Iodine standard solution 1c (1/21) = 0.0473 mol/dm, preparation and calibration see Appendix A4. 10
Thiosulfate standard titration solution: c (Na2S, O.) = 0.0394 mol/clm. Preparation and calibration see Appendix A4.11
Free starch solution: 10 g/dm\, preparation see Appendix A. 4.12
Phenolic acid indicator: 10 g/dm, preparation see Appendix A. 4.13
Approved by the State Administration of Quality and Technical Supervision on November 4, 1998 and implemented on June 1, 1999
4.14 Saturated sodium bicarbonate solution.
Test equipment and instruments
5. 1 Analytical balance; accuracy (. 1 mg. GB/T3780.1-1998
5-2 Scale stopper glass centrifuge bottle with a capacity of 50 cm, 5.3 Flame: controllable flow rate is (1251℃, temperature is above 5℃. 5.4 Filter tube: the following two types can be selected: 5.4.1 Digital burette: capacity is 25 cm, counter increment is 0.01 cm, can be adjusted to zero. 5.4.2 Brown glass burette: capacity is 25m%A grade, medium position 0.1 cm 5. 5 Centrifuge; the number of revolutions will be above 1 000 r/min e5.6 Volumetric flask: capacity 1 tion cmz, genuine grinding glass case. 5.7 Funnel: standard diameter with taper: interface crane and 1000 cm\ volumetric flask. 5.8 Oscillator: 240 times/ni1.
5. 9 Carbon volumetric flask: 250 cml.
6 Test conditions
Carry out in a room with a temperature of (23±2)℃, relative humidity of (50±5)% or a temperature of (27±2)℃, relative condensation of (65±5)%. 7 Operation steps and results
7.1 Method A (arbitration method)
7.1.1 Take an appropriate amount of carbon black sample and dry it in a -125℃ oven for 1 h, cool it to room temperature in a desiccator, 7.1.2 Weigh a quantitative amount of carbon black sample in a centrifuge bottle according to Table 1 (weigh to 0.1mR). Table 1
Absorption range·product/g
n. 0~- 13c. 9
131. 0~-280.9
281. 0~~520.9
521.n and above
test·g
iodine drop solution to sample ratio (V/m)
50:1
1If the measurement result of the sample volume determined by the predetermined absorption value is not within the specified range, the actual measured value shall be used as shown in Table 1 The corresponding sample volume in the test is retested.
2 The powdered carbon black sample should be compacted before weighing. 3 The sample volume specified in the table corresponds to 25 cm2 of iodine standard solution. Under the condition that the ratio of iodine standard solution to sample volume specified in the table is met, the maximum allowable sample volume is 1.0000. As the test volume and the corresponding solution volume increase, a centrifuge of appropriate capacity should be selected to ensure the vibration effect. 7.1.3 Pipette 25 cm2 of iodine standard solution (4.10) into a centrifuge bottle and stopper it. Vibrate on a vibrator at a rate of 240 times/min for 1 min, and immediately centrifuge for separation. The separation time for granular carbon black samples is 1 min, and for powdered carbon black samples is 3 min. 7.1.4 Gently pour the clear liquid. If there is more than one sample, pour the clear liquid into a clean, dry narrow-necked bottle and stopper it immediately. 7.1.5 Pipette 20 cm2 of clear liquid and 250 cm\iodine volume bottle. Use sodium thiosulfate standard titration solution (4.11) and use a digital burette or a glass burette to titrate according to the following steps. 7.1.5.1 Titration with a digital burette
1.5.1.1 Adjust the switch to the filling position, so that the burette is filled with thiosulfate standard titration solution, and use this solution to rinse the inlet and discharge tube. GB/T 3780. 1—1998
7.1.5-1.2 Adjust to the titration position, return the counter to zero and wipe the tube with silk paper. 7.15.1.3 Add sodium thiosulfate standard titration solution until it turns light yellow, and rinse the tip of the burette and the bottle wall with water. Add 5 drops of starch solution, and continue to add sodium thiosulfate standard titration solution until the blue color almost disappears, and then rinse the tip of the burette and the bottle wall with water. Adjust the counter increment to 0.01cm and continue titrating until it becomes colorless, which is the end point. 7.1.5.1.4 Record the burette reading. Accurate to 0.01cm1. 7.1.5.1.5 Take 20cm of iodine standard solution for blank test and take the average of two results. If both solutions meet the requirements, the blank test result should be (24.00±0.05)cm. Otherwise, recheck the concentrations of both solutions. 7.1.5.2 Titration with glass burette
7.1.5.2.1 Take a clean 25cm~ burette and fill it with sodium thiosulfate standard solution and adjust it to zero. Wipe the tip of the burette with silk paper and drip sodium thiosulfate standard solution until it turns light yellow. Rinse the tip and the wall of the titration bottle with water, add 5 drops of starch solution, and continue to drip sodium thiosulfate standard solution until the last drop becomes colorless. This is the end point. 7.1.5.2.2 Record the burette reading, with an accuracy of 0.01 cm. 7.1.5.2.3 Perform a blank test according to 7.1.5.1.5. 7.1.6 Results and calculation:
Iodine absorption value is expressed as the mass of iodine absorbed per gram of carbon black (in grams) (g/kg), calculated according to formula (1). V. -V,V
: I-
Iodine absorption value, g/kg
2.c×126.91
-Volume of sodium thiosulfate standard titration solution consumed in titrating blank iodine standard solution, cm1\; V.--
Volume of sodium thiosulfate standard titration solution consumed in titrating carbon black sample iodine standard solution.cm\; V
-Volume of iodine standard solution absorbed, cm
Mass of carbon black sample + g:
Concentration of iodine standard solution (6.2) + mol/dm
and 1.00 dm\ sodium thiosulfate standard titration solution. [c(NazSO,)=1.000mol/dm, the mass of iodine expressed in grams. 7.2 Method
7.2.1 Take an appropriate amount of carbon black sample and dry it in a 125°C oven for 1 h. Place it in a desiccator and cool it to room temperature. Weigh a quantitative amount of dry carbon black sample according to Table 2 and place it in a centrifuge bottle (accurate to 0.1 m2 g). 7.2. 2
Iodine adsorption value range, g/kgwww.bzxz.net
0. 0~~130. 9
131.0--280.9
281, 0~520. 9
521.0 and above
Sample+g
-(1)
If the measurement result of the sample amount determined by the expected iodine adsorption value is not within the specified range, it should be measured according to the loss? The corresponding test column base is new test 1
2 The powdered carbon black sample should be compacted before weighing. 7.2.3 Pipette 40 cm2 of iodine standard solution into centrifuge bottle A, immediately stopper it, shake it on an oscillator at a rate of 240 times/min for 1 minute, immediately remove it and centrifuge it. The separation time for granular carbon black samples is 1 minute, and for powdery carbon black samples is 3 minutes. 7.2.4 Gently pour out the clear liquid from the centrifuge bottle. If there are more than one fluorescent black sample, the clear liquid should be put into a clean, dry fine-mesh bottle and stoppered immediately.
GB/T 37B0. 1---1998
7.2.5 Pipette 25 cm2 of the full liquid into a 250 cm iodine volumetric flask and titrate it with sodium thiosulfate standard titration solution (4.11). Use a digital burette or a glass burette to titrate according to the following steps: 7.2.5. 1 Titration with a digital burette
7.2.5.1.1 Adjust the switch to the filling position to fill the burette with sodium thiosulfate standard titration solution. Use this solution to rinse the inlet and infusion tube. 7.2.5.1.2 Adjust to the titration position to return the counter to zero and wipe the tip with thin paper. 7.2.5-1.3 Add sodium thiosulfate standard titration solution until it turns light yellow, and rinse the burette tip and bottle wall with water. Add 5 drops of starch solution, continue to add sodium thiosulfate standard titration solution until the blue color almost disappears, and then rinse the burette tip and bottle wall with water. Adjust the counter increment to .lctn, and continue titrating until it becomes completely colorless, which is the end point. 7.2.5.1.4 Record the burette reading to 0.01 ctm. 7.2.5.1.5 Take 25 cm of iodine standard solution to perform blank test and take the average of the two results. If both solutions meet the requirements, the blank test result should be (30.00 + 0.05) cm. If not, recheck the concentrations of both solutions. 7.2.5.2 Titration with glass burette
7.2.5.2.1 Take a clean 25 cm burette and fill it with sodium carbofuran standard titration solution. Adjust to zero. Wipe the tip of the burette with tissue paper and drip sodium thiosulfate standard titration solution until it turns light yellow. Rinse the tip of the burette and the wall of the bottle with water, add 5 drops of vortex solution, and continue to drip sodium thiosulfate standard titration solution until the last drop becomes colorless. This is the end point. 7.2.5.2.2 Record the reading of the burette, accurate to 0.1 cm. 7.2.5-2.3 Perform the dense film test according to 7.2.5. [. 5]. 7.2.6 Results and calculation: Calculate the iodine absorption value according to formula (2)~5), accurate to 0.5/kg, the mass of the sample is 0.8000g, the mass of the test column is 0.4000%, the mass of the sample is 0.2000g, the mass of the sample is 1000g, where: f-iodine absorption value g/kg
I.(V-V,) × 10
1= (V-V,) × 20
I-(V-V,) XA +**
I-(VV) × 80
.--Volume of sodium thiosulfate standard titration solution consumed by the main test + cmV:---Volume of sodium thiosulfate standard titration solution consumed by carbon black sample iodine standard solution cm8Test result value
: The test result should be expressed according to the effective digit specified in (33778). h) The test data should be one more effective digit than that specified in GI33778, and then be rounded according to GB8170. 9 Precision
9.1 Coin refolding: Same as: Experimental space The pad of the drilled fruit in the first test shall not exceed 1.1g/kg. 9.2 Current property: The difference between the two test results of different laboratories shall not exceed 3.4.R/kR: 10 Test report
The test report will include the following contents:
a) Sample mark and number;
b) Test quality
e) Average value of the two test results:
d) Test procedure (A method or B method) and titration method used:) Common phenomena in the test.
++++++( 3)
........-(4)
（5）
41 Preparation of solution
GB/T 3780. 1---1998
Appendix A
(Appendix to the standard)
Preparation and calibration of solution
A41. 1 Iodine standard solution: c(1/2I,)--0. 472 8 mol/dmA1.1.1 Weigh 1110 g potassium iodide into a 1000 cm\ beaker, take about 850 grams of iodide from it, pass through a large diameter bucket into a clean 2 000 tm volumetric flask. Add water to immerse the potassium iodide in the flask, shake it to dissolve it and let it stand until it reaches room temperature. A1.1.2 Weigh 50 g potassium iodide-F250 from the 1000 cm\ beaker Add appropriate amount of water to the 1 cm beaker to dissolve. Add 300 l of water to dissolve the potassium iodide remaining in the 1 cm beaker.
A1.1.3 Use a high-type weighing bottle with a ground-mouth stopper to weigh 120. (ig) iodine, and rinse the iodine into the 2000 cm narrow volumetric flask (A1.L.1) through a large-diameter funnel with the potassium iodide solution in the 1 000 cm beaker.
Note: When weighing iodine, use a weighing bottle with a small toe and transfer the solution with a porcelain spoon. 41.1.4 Use the iodide solution (A1.1.2) in the 250 ml beaker to continuously rinse the weighing bottle into the 2000 cm narrow volumetric flask (A1.L.1) until there is nothing else in the weighing bottle.
A1.1.5 Concave volumetric flask with magnetic stirrer 1:, stir at medium speed for 30-60 min, dilute to scale, invert once, and place on magnetic stirrer to stir continuously for at least 2 h,
Juice: do not consider the volume occupied by the stirring rod
A1.1.6 Transfer the solution to a brown bottle and leave it for more than 12 h. Stir for 5 min before transfer. A1.2 Iodine standard solution: r(1/21z) = -0.0173 mol/dm. 2000 cm of iodine can be used. C (1/21-℃.4728mm/dt is accurate to 10 times. Prepare 20dn of drying standard solution ct1/21,1-0.0473mol/dm* or prepare it in the following steps. 41-2. 1 Weigh 912 g of potassium iodide at -1 00G cm and burn it. Take about 700 The 100 g of chemical supply is passed through a large diameter funnel into a 20 dm corrugated glass container. Add water to cover it and shake it to dissolve, then let it stand until it reaches room temperature. A1.2.2. Weigh 5% potassium iodide in a 300cm2 beaker and dissolve it in 250cm2 of water. Dissolve the potassium iodide remaining in the 100cm2 beaker with 30℃ water. 41.2.3 Use a high-end weighing bottle to weigh 96.0000 g of potassium iodide solution through a large diameter bucket H1000 cm2 and rinse the iodine into a 20 dm glass container.
A1-2.4 Use the potassium iodide solution in the 250cm2 beaker to continuously rinse the iodine adhering to the 20 dm glass container.
A1.2.5 Add water at 2-3 dm and stir until the scale is slightly below 15 dm. Place on a magnetic stirrer and stir at medium speed for 30-60 min. Add water to the 16 dm scale. Shake vigorously and stir on a magnetic stirrer for more than 12 h. Note: If the solution is too small or too little, you can prepare a smaller amount. A1.3 Sodium thiosulfate standard dye solution: r(NagS,0,)-0.0394 mol/dmA1.3.1 Add about 1 dm of water to a 16 dm glass vessel and weigh 156.5 g of sodium thiosulfate.
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