4,4'-(2,3-epoxypropoxy)-2,2'- dimethyl-5,5'-tert-butyldiphenylsulphide

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

4 January 2011 to 10 January 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

ISO 13320 (Particle size analysis - Laser diffraction methods)

Version / remarks:

2009

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: CIPAC MT 187

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions - Method A: Particle Size Distribution (effective hydrodynamic radius)

GLP compliance:

yes (incl. QA statement)

Type of method:

Laser scattering/diffraction

Mass median aerodynamic diameter:

211.241 µm

Geometric standard deviation:

0.02

Key result

Percentile:

D50

Mean:

211.241 µm

St. dev.:

4.34

Key result

Percentile:

D10

Mean:

72.016 µm

St. dev.:

2.39

Key result

Percentile:

D90

Mean:

445.345 µm

St. dev.:

13.6

No.:

#1

Size:

< 10 µm

Distribution:

0 %

OPTICAL MICROSCOPE ANALYSIS

- Standard visual observation: The test material sample was observed to be a coarse, gritty powder with clusters, some of the clusters were greater than 2000 μm.

- Observation at 100 x magnification: The particles appeared to be irregular shaped crystals. The smallest individual particle size was approximately 6.4 μm and the largest individual size was approximately 640 μm.

- Observation at 400 x magnification: The sample was observed to be made up of both single and agglomerated crystalline particles.

MANUAL SIEVE ANALYSIS

- Result : 96.91% by weight < 2000 μm

Table 1: Manual Sieve Analysis Results

Sieve Size (µm)	Sieve Weight (g)	Sieve + Powder Weight (g)	Powder Weight (g)	% By Weight
> 2000	325.9	331.5	5.6	3.09
< 2000	246	421.8	175.8	96.91
TOTALS			181.4	100

 

SOLUBILITY TEST FOR PARTICLE SIZE ANALYSIS

- Preliminary solubility and dispersability for particle size analysis: The sample was well dispersed in 3 of the 6 solvent tested. For the full solubility and dispersability test, sunflower oil was selected.

Table 2: Preliminary solubility and dispersability results

Solution Used	Soluble (y = yes, n = no)	Insoluble (y = yes, n = no)	Comments
Water	n	y	Poor dispersability
Methanol	n	y	Good dispersion
Acetone	y	n	Soluble
Kerosene	n	y	Sample deformation observed
Silicone Oil	n	y	Well dispersed
Sunflower Oil	n	y	Good dispersability

- Solubility and dispersability test for particle size analysis: The test material sample proved to be insoluble, and well dispersed in sunflower oil. Therefore sunflower oil was to be used for the suspension fluid.

Table 3: Main solubility and dispersability test (Dispersant used: Sunflower oil)

Time elapsed	Series 1			Series 2
	1 (1.5 mg)	2 (1.5 mg)	3 (1.5 mg)	1 (5.0 mg)	2 (5.0 mg)	3 (5.0 mg)
10 seconds	Well dispersed			Well dispersed
30 minutes	Well dispersed			Well dispersed
60 minutes	Well dispersed			Well dispersed
90 minutes	Well dispersed			Well dispersed
120 minutes	Well dispersed			Well dispersed

LASER DIFFRACTION PARTICLE SIZE ANALYSIS

Table 4: Laser Diffraction Analysis Results

	RUN 1	RUN 2	RUN 3	RUN 4	RUN 5	*Average
Volume Weighted Mean	235.594	228.778	244.854	238.214	245.862	238.660
Median (d.50)	207.453	204.767	214.085	214.419	215.672	211.241
Mode (µm)	242.022	245.312	249.104	252.254	249.995	247.901
10 % of material is <	69.196	69.129	74.517	73.653	73.849	72.016
50 % of material is <	207.453	204.767	214.085	214.419	215.672	211.241
90 % of material is <	444.534	424.585	458.633	438.608	461.846	445.345

All results are in μm

* Average result is calculated from the entirety of data captured in each run and is not a simple arithmetic mean.

0 % by volume of sample was seen to be < 10.00 μm.

Table 3: Standard Deviation Results

Run No.	1	2	3	4	5	ST DVP	% STDV
d10	69.196	69.129	74.517	73.653	73.849	2.39	3.32
d50	207.453	204.767	214.085	214.419	215.672	4.34	2.05
d90	444.534	424.585	458.633	438.608	461.846	13.60	3.05
d15.78	91.660	90.450	96.660	96.740	96.490	2.76	2.92
*GSD	2.263	2.264	2.215	2.216	2.235	0.02	0.96

*GSD = Geometric standard deviation

Coefficient of variation for d50 is less than 3%; d10 and d90 are less than 5%. Thus repeatability of the characteristic particles in the size distribution are within the acceptable limits as per the BS ISO 13320-1 test standard.

Conclusions:

Under the conditions of this study 0% by volume of the test material sample was seen to be < 10.00 μm.

Executive summary:

The particle size distribution of the test material was investigated in accordance with the standardised guidelines ISO 13320:2009 and CIPAC MT 187, taking into consideration OECD guideline 110. The testing was performed under GLP conditions.

Due to poor reproducibility being obtained in the dry powder module, the analysis was carried out using the ‘wet’, small volume dispersion system. Several solvents were tried, in order to determine a suitable medium that provided maximum dispersability, but with minimum solubility. Sunflower oil was finally selected as the most suitable dispersant.

Manual sieve analysis indicated that 96.91% by weight of the sample had a particle size of < 2000 μm. A subsequent laser diffraction analysis on the < 2000 μm sample produced the following results: Volume weighted mean = 238.660 µm, Median (d.50) = 211.241 µm, Mode = 247.901 µm, 10% of material is < 72.016 µm, 50% of material is < 211.241 µm and 90% of material is < 445.345 µm.

Under the conditions of this study 0% by volume of the test material sample was seen to be < 10.00 μm.

Description of key information

Under the conditions of the study 0% by volume of the test material sample was seen to be < 10.00 μm.

Additional information

The particle size distribution of the test material was investigated in accordance with the standardised guidelines ISO 13320:2009 and CIPAC MT 187, taking into consideration OECD guideline 110. The testing was performed under GLP conditions. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

Due to poor reproducibility being obtained in the dry powder module, the analysis was carried out using the ‘wet’, small volume dispersion system. Several solvents were tried, in order to determine a suitable medium that provided maximum dispersability, but with minimum solubility. Sunflower oil was finally selected as the most suitable dispersant.

Manual sieve analysis indicated that 96.91 % by weight of the sample had a particle size of < 2000 μm. A subsequent laser diffraction analysis on the < 2000 μm sample produced the following results: Volume weighted mean = 238.660 µm, Median (d.50) = 211.241 µm, Mode = 247.901 µm, 10% of material is < 72.016 µm, 50% of material is < 211.241 µm and 90% of material is < 445.345 µm.

Under the conditions of the study 0% by volume of the test material sample was seen to be < 10.00 μm.