ISO 15825:2017 pdf download – Rubber compounding ingredients — Carbon black — Determination of aggregate size distribution by disc centrifuge photosedimentometry.
5 Apparatus 5.1 Disc centrifuge photosedimentometer (DCP) 1) , capable of rotational speeds of 1 000 r/min to 11 000 r/min or greater, with integral spin feed-back control (accuracy and stability of rotational speed better than ± 0,05 %), spin fluid volume from 10 cm 3 to 20 cm 3 , stable temperature of spin fluid, stroboscope to monitor the rotating disc both for stability and streaming anomalies, and an appropriate optical turbidity measuring device. 5.2 Energy meter, capable of measuring the energy consumption (in kWh) of the probe-type sonicator. The energy meter is inserted between an electrical plug of the laboratory and the plug of the power supply cord of the sonicator. The actual energy consumption is indicated on a digital display. 5.3? Probe-type? sonicator 2) , typically with a nominal power of 200 W or more. The sonicator should be capable of providing a measured power consumption of at least 60 W. This has been found to be an effective means of dispersing carbon black into discrete aggregates. See Clause 8 for further details. NOTE Cylindrical tips with 12,7 mm (1/2 inch) diameter have been found to be suitable. 6 Reagents and materials Unless otherwise stated, use only reagents of recognized reagent grade 3) . 6.1 Water, distilled or deionized, grade 3 as defined in ISO 3696. 6.2 Ethanol, absolute. 6.3 Surfactant, non-ionic type 4) , 0,02 % to 0,05 % (by mass) solution.3.2.3 median D 50 x-value of the point on the mass distribution curve at which 50 % by mass of the test sample is larger and 50 % by mass of the test sample is smaller Note 1 to entry: It represents the median value of the distribution. Note 2 to entry: In the software of the Brookhaven disc centrifuge the median Stokes diameter is reported as “d50”. Note 3 to entry: D 50 is used for reporting purposes only. 3.2.4 mode D mode value at which the most frequent diameter occurrence is observed, which is portrayed as a peak in the distribution curve Note 1 to entry: In some cases, there may be more than one mode indicated. Note 2 to entry: D mode is used for reporting purposes only. 3.2.5 lower quartile x-value of the point on the mass distribution curve at which 75 % of the sample is larger, and 25 % smaller 3.2.6 upper quartile x-value of the point on the mass distribution curve at which 75 % of the sample is smaller, and 25 % larger 3.2.7 quartile ratio ratio of upper quartile to lower quartile Note 1 to entry: In the software of the Brookhaven disc centrifuge the quartile ratio is reported as “d75/d25”. 3.2.8 ΔD-50 width of the plot of the mass distribution measured at the half-maximum point of the mode, which is a measure of the breadth of the aggregate size distribution Note 1 to entry: In the software of the Brookhaven disc centrifuge ΔD 50 is reported as “FWHM” (full width at half maximum). 4? Significance? and? use Disc centrifuge photosedimentometry produces a rapid mass-differential aggregate size distribution, by continuously measuring the solution turbidity as a function of centrifugation time. In order to obtain a true mass distribution, a light scattering correction shall be applied. An example of a mass distribution curve is given in Annex A.
ISO 15825:2017 pdf download – Rubber compounding ingredients — Carbon black — Determination of aggregate size distribution by disc centrifuge photosedimentometry
