GB 5177.2-1985 Determination of sulfonate content in industrial alkylbenzenes

This standard is applicable to the determination of sulfonates in industrial alkylbenzenes. GB 5177.2-1985 Determination of sulfonates in industrial alkylbenzenes GB5177.2-1985 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of sulphonatable mattercontent for industrial alkylbenzene This standard is applicable to the determination of sulphonatable matter in industrial alkylbenzene. 1 Principle
UDC 547.52: 543
GB 5177.2-85
This method is to sulfonate industrial alkylbenzene with oleum, neutralize it with sodium hydroxide, and extract the non-sulfonated matter with n-pentane (or petroleum ether). The percentage of sulphonatable matter is obtained by subtraction. 2 Definition
Sulfonatable matter is an alkylated matter that can react with oleum under the test conditions. 3 ApparatusbZxz.net
3.1 Electric stirrer.
3.2 Three-necked flask, 100ml.
3.3 Mercury thermometer, 100℃, graduation 1℃. 3.4 Dropping funnel, 60 ml.
3.5 Measuring cylinder with stopper, 250 ml.
3.6 Measuring cylinder, 100 ml.
3.7 Siphon, inner diameter 3-4 mm, inner diameter of tube end 1-2 mm. 4 Reagents
4.1 Oleum (prepared to contain SO: 20%), analytical grade. 4.2 Sodium hydroxide (granular), analytical grade. 4.3 95% ethanol, analytical grade.
4.4 n-Pentane (or petroleum ether, distillation range 30-60°C), analytical grade. 4.5 Acetone, analytical grade.
5 Test procedure
5.1 Accurately weigh 10 g (accurate to 1 mg) of alkylbenzene sample into the three-necked flask (3.2) (add the sample carefully and do not splash the sample on the wall). Install a stirrer (3.1) and a thermometer (3.3) at the mouth and side of the three-necked flask, respectively. Weigh fuming sulfuric acid (4.1) in a dropping funnel (3.4) at a hydrocarbon: acid ratio of 1:1.2 (mass), and insert the dropping funnel into the other side of the three-necked flask. Start the stirrer, but not too fast, and adjust the water bath temperature to 51°C. When the liquid temperature in the reaction flask rises to 51°C, start dripping fuming sulfuric acid, and the acid addition speed should be such that the reaction temperature is maintained at 55±1°C. After 5 minutes of reaction, speed up the stirring. The acid addition time is 20 minutes, and then the temperature is maintained at 55±1°C and the stirring is continued for 20 minutes.
5.2 After the sulfonation is completed, cool the reactants to below 40°C, neutralize with 14% sodium hydroxide solution to pH 7-8 (using phenol as an indicator), and control the neutralization temperature at 50-60°C. Then use 80ml hot distilled water to transfer the reactants quantitatively to the stoppered measuring cylinder (3.5), and then use 50ml ethanol (4.3) to wash the three-necked flask, stirrer and thermometer, and put the washing liquid into the stoppered measuring cylinder. Issued by the National Bureau of Standards on May 10, 1985
Implemented on January 1, 1986
GB 5177.2-85
5.8 Extraction of unsulfonated substances
Cool the contents of the stoppered measuring cylinder to room temperature, cover the stopper of the measuring cylinder, and shake it up and down vigorously to dissolve it completely. Then, use 50ml n-pentane (or petroleum ether) (4.4) to wash the three-necked flask, stirrer and thermometer, and put the washing liquid into the stoppered measuring cylinder, cover the stopper of the measuring cylinder, shake it up and down several times, carefully open the stopper, rinse the stopper and the wall of the measuring cylinder with a small amount of n-pentane, and let it stand for stratification. After the layers are separated, insert a siphon tube (3.7) with the mouth of the tube 5 to 6 mm above the interface of the n-pentane-alcohol solution, and siphon the upper clear liquid into a pre-weighed distillation bottom bottle. Be careful not to bring in the lower alcohol solution. Repeat the extraction four times according to the above operation, and put the extract into the distillation bottom bottle. Install the solvent recovery device and recover the solvent in a water bath at 60 to 70°C until no distillate flows out. Remove the distillation bottom bottle, put it on a water bath, add 2 ml of acetone, insert the blowing tube to 5 cm from the bottom of the bottle, and drive away the residual solvent with a dry air flow of 2 L/min. After 2 minutes, wipe the distillation bottom bottle with clean dry gauze, move it to a desiccator and cool it for 15 minutes before weighing. Repeat this operation, but blow for 1 minute each time. The difference between the two weighings before and after is within 20 mg, which is the constant weight.
Blank test
Put 200ml of n-pentane (or petroleum ether) into a pre-weighed distillation bottom bottle, and perform a blank test according to the solvent recovery operation in 5.3. 6 Calculation
The content of sulfonated substances in industrial alkylbenzene is calculated according to the following formula: Sulfonated substances %=
W-weighed sample amount, g,
W——residue amount in the bottle, g,
W.—blank test residue amount, g.
W-- (Wi-Wo)
The difference between the results of two parallel tests should not exceed 0.2%. ×100
Additional instructions:
This standard was proposed by the Ministry of Light Industry of the People's Republic of China and is under the technical jurisdiction of the Daily Chemical Industry Scientific Research Institute of the Ministry of Light Industry. This standard was drafted by the Daily Chemical Industry Scientific Research Institute of the Ministry of Light Industry. The main drafters of this standard are You Lintai, Hu Dehua and Wang Peiwei. 15
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