ISO 1304:2016 pdf free

ISO 1304:2016 pdf free.Rubber compounding ingredients – Carbon black
NOTE Previous editions of this International Standard required a thiosulfate concentration of 0,039 4 mol/dm3 [0,039 4 N]. Since the concentration of the thiosulfate solution does not have any impact on the iodine adsorption number, this International Standard now includes a more commonly used solution of 0,05 mol/dm3 (0,05 N). The advantage is that such a solution is readily available commercially. If preferred, it can be prepared from solid sodium thiosulfate as described below.
Use of sodium thiosulfate solution of 0,039 4 mol/dm3 (0,039 4 N) is still permitted. In this case, the instructions for the preparation of the solution, the formulae used in its standardization and the formulae used in the calculation of the iodine adsorption number will have to be modified accordingly.
Weigh, to the nearest 0,005 g, 24,817 g of sodium thiosulfate pentahydrate (5.5) into a suitable container.
With the help of a funnel, transfer the weighed sodium thiosulfate to a 2 000 cm3 volumetric flask (4.3).
Add through the funnel about 1 litre of water (5.1). Wash carefully.
Add 10 cm3 of n-amyl alcohol (5.6) to the flask, and shake the solution in the flask vigorously until all crystals are dissolved.
Make up to the mark with water (5.1), insert a spin bar in the flask, place it on the magnetic stirrer and stir for about 2 h at medium speed (see 6.1.10).
In a 1 000 cm3 volumetric flask (see 4.3), dissolve 57,0 g (weighed to the nearest 0,1 g) of potassium iodide (5.3) in about 200 cm3 of water (5.1). Allow to stand until the solution attains ambient temperature.
Weigh out, to the nearest 0,1 mg, 1,783 3 g of the freshly dried potassium iodate (5.4) and transfer to the iodide solution in the volumetric flask.
Make up to the mark with water (5.1). Cap the flask and homogenize the solution by inverting the flask 4 to 5 times.
Transfer the solution to an amber-glass bottle (4.8).
NOTE The potassium iodate/iodide solution is a primary standard in this test method, and it is essential that all precautions be taken to ensure its accuracy.
Measure out 175 cm3 of water (5.1) in a graduated cylinder and transfer to a 250 cm3 conical flask.
Measure out 25 cm3 of concentrated sulfuric acid (5.7) in a small graduated cylinder.
Very carefully pour the acid into the flask of water (6.4.1), and swirl gently to mix. Rinse the graduated cylinder with diluted acid from the flask and pour the rinsings back into the flask. Do not use water for rinsing.ISO 1304 pdf download.