2,2'-[1,3-phenylenebis(oxy)]bisethanol

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:

Start date of the experimental work: 1 February 2018 and completion date of the experimental work: 8 May 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Version / remarks:

Manual sieve analysis and laser diffraction analysis

Deviations:

not applicable

Principles of method if other than guideline:

To characterise the particle size distribution of the powder. The analysis is conducted initially using a visual microscope and is then undertaken more formally using a Laser Diffraction Particle Size Analyser. The benefit of this procedure is that it allows the operator to obtain a better understanding of the particle characterisation of the material. This includes, but is not limited to, sample clusters and agglomerations which may provide false values in the formal particle size analysis. In these situations, where the operator can assess how easily these clusters or agglomerations are dispersed, ultrasonics may be employed. Owing to the extremely small quantities of material used in this analysis it should be noted that discrepancies can arise between the lower and upper limits of the particle size and the actual value obtained in the formal particle size analysis.
The sample is observed under 3 conditions:
- Direct observation
- Under a microscope using 3.2 objective lens
- Under a microscope using 40 objective lens

GLP compliance:

yes (incl. QA statement)

Type of method:

other: manual sieveing analysis and laser diffraction analysis

Type of particle tested:

other: powder

Key result

Percentile:

other: 10%

Mean:

< 44.9 µm

Remarks on result:

other: Particle Size Analysis using small volume (wet) module (SVM) with Silicone Oil as the dispersant

Key result

Percentile:

other: 50%

Mean:

< 195 µm

Remarks on result:

other: Particle Size Analysis using small volume (wet) module (SVM) with Silicone Oil as the dispersant

Key result

Percentile:

other: 90 %

Mean:

< 691 µm

Remarks on result:

other: Particle Size Analysis using small volume (wet) module (SVM) with Silicone Oil as the dispersant

Key result

Percentile:

other: 0.25 %

Mean:

< 10 µm

Remarks on result:

other: by volume of sample was seen to be < 10.00 μm is 0.25%

Percentile:

other: 88.6% by weight of the sample

Mean:

< 2 000 µm

Remarks on result:

other: Manual sieve analysis

Manual sieve Analysis:

Results: 88.6% by weight < 2000 μm

Full test results:

Sieve size (μm)	Sieve weight (g)	Sieve + powder weight (g)	Powder weight (g)	% by weight
< 2000	325.47	1037.53	712.1	88.6
> 2000	349.44	441.41	92.0	11.4
		TOTALS	804.0	100.0

Preliminary Solubility And Dispersability For Particle Size Analysis results

Solution used	Soluble	Comments
Silicone oil	No	Good dispersability

Comment

Sample had surface active properties and this limited the choice of dispersants. However the sample was found to be well dispersed in silicone oil. Thus silicone oil was investigated and applied for the analysis.

Solubility And Dispersability Test For Particle Size Analysis

Dispersant used: Silicone Oil

	Series 1			Series 2
Time elapsed	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

Comments : The sample proved to be insoluble, and well dispersed in silicone oil. Silicone oil was therefore used as the dispersant.

LASER DIFFRACTION PARTICLE SIZE ANALYSIS RESULTS:

	Run 1	Run 2	Run 3	Run 4	Run 5	Average **
Volume weighted mean	312	284	306	336	314	106
Median	199	192	188	202	197	195
Mode	327	336	304	327	328	324
d10 - 10 % of material is <	45.2	44.6	44.3	45.3	44.9	44.9
d50 - 50 % of material is <	199	192	188	202	197	195
d90 - 90 % of material is <	701	630	680	756	701	691

All results are in μm

* Mass median aerodynamic diameter

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

0.25 % by volume of sample was seen to be < 10.00 μm.

Standard deviation results

Run N°	1	2	3	4	5	STDVP	% STDVP
d10 - 10 % of material is <	45.2	44.6	44.3	45.3	44.9	0.406	0.905
d50 - 50 % of material is <	199	192	188	202	197	5.52	2.82
d90 - 90 % of material is <	701	630	680	756	701	45.1	6.51
GSD	2.894	2.787	2.892	2.981	2.903	0.062	2.1

GSD = Geometric standard deviation of the lognormal particle size distribution (calculated from d50/d15.78)

STDVP = standard deviation of the population

% STDVP = percentage standard deviation of the population

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

Comment

Although the largest particles observed under microscopic investigation were < 500 μm, the sample was sieved to remove lumps/ agglomerations of size > 2000 μm prior to the distribution analysis. It was extremely difficult to breakdown the clumps into individual particles before or during the distribution analysis.

From the standard deviation calculations, d10 and d50 are within the acceptable limits set by the ISO 13320-1 protocol but the d90 was out.

This may be attributed to the inability to breakdown the lumps into individual particles using the apparatus impeller.

Conclusions:

Particle Size Analysis using small volume (wet) module (SVM) with Silicone Oil as the dispersant.
Volume weighted mean 310 μm
Median (d.50) 195 μm
Mode 324 μm
10 % of material is < 44.9 μm
50 % of material is < 195 μm
90 % of material is < 691 μm
by volume of sample was seen to be < 10.00 μm
0.25% Manual sieve analysis indicated that 88.6 % by weight of the sample had a particle size of < 2000 μm. A subsequent laser diffraction analysis on the < 2000 μm sample produced the results above.

Description of key information

Particle Size Analysis using small volume (wet) module (SVM) with Silicone Oil as the dispersant.

Volume weighted mean 310 μm

Median (d.50) 195 μm

Mode 324  μm

10 % of material is < 44.9 μm

50 % of material is < 195 μm

90 % of material is < 691 μm

by volume of sample was seen to be < 10.00 μm

0.25% Manual sieve analysis indicated that 88.6 % by weight of the sample had a particle size of < 2000 μm. A subsequent laser diffraction analysis on the < 2000 μm sample produced the results above.