Bis(hydroxyethyl) terephthalate

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:

Experimental starting date 23rd July 2021 . Experimental completion date 26th July 2021. Final study report 7th October 2021.

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions) - Method B: Fibre Length and Diameter Distributions

Version / remarks:

1981 A sieve tower was used to determine the size until 1.4mm

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 13320 (Particle size analysis - Laser diffraction methods)

Version / remarks:

2009 -the particles below 1.4 mm were determined by the method of laser diffraction.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

Laser scattering/diffraction

Type of particle tested:

agglomerate

Remarks:

The particle size distribution of the dry weak dispersion test method GRADIS/L showed, that the particle, as they exist, were agglomerated and the distribution of the particles were very large.

Specific details on test material used for the study:

Name BHET Batch no.AWS0284C
CAS no.959-26-2
Composition
Bis-2-Hydroxy Ethyl Terephthalate (BHET) ~94 wt%; BHET dimer ~5 wt%; Mono 2-Hydroxy Ethyl Terephthalate (MHET) <1.0 wt%; 2-Hydroxy Ethyl 2-(2-Hydroxy Ethoxy)Ethyl Terephthalate <0.5 wt%; Bis-2-Hydroxy Ethyl Isophthalate (BHEI) <0.1 wt%; Ethylene Glycol <1.0 wt%; Water <0.2 wt%
Storage room temperature (20 ± 5 °C)
Expiry date 02. Apr. 2023
Stability stable under storage conditions
Appearance White solid
Purity ~95 %
Homogeneity homogeneous
Production date 15. Dec. 2020
EC no. 213-497-6
Molecular formula C12H14O6
Molecular weight 254.24 g/mol
Vapour pressure not stated
Solubility in solvents:-
H2O: > 1 g/L; EtOH: not stated; acetone: not stated; CH3CN: not stated; DMSO: not stated;
Stability in solvents:
H2O: not stated; EtOH: unknown; acetone: unknown; CH3CN: unknown; DMSO: unknown

Mass median aerodynamic diameter:

> 280.89 - < 499.99 µm

Key result

Percentile:

D90

Mean:

<= 2 140.92 µm

Remarks on result:

not measured/tested

Remarks:

D90 of the 36% less than 1.40 mm. Standard deviation not calculated; ranged from 874.9 to 2140.92 µm (min & max values following 3 runs)

Key result

Percentile:

D50

Mean:

<= 499.99 µm

Remarks on result:

not measured/tested

Remarks:

D50 of the 36% less than 1.40 mm. Standard deviation not calculated; ranged from 280.89 to 499.99 µm (min & max values following 3 runs)

Key result

Percentile:

D10

Mean:

<= 39.09 µm

Remarks on result:

not measured/tested

Remarks:

D10 of the 36% less than 1.40 mm. Standard deviation not calculated; ranged from 31.88 to 39.09 µm (min & max values following 3 runs)

No.:

#8

Size:

< 1.4 mm

Distribution:

ca. 36.18 %

No.:

#7

Size:

ca. 1.4 mm

Distribution:

ca. 9.55 %

No.:

#6

Size:

ca. 2 mm

Distribution:

ca. 10.59 %

No.:

#5

Size:

ca. 2.8 mm

Distribution:

ca. 25.53 %

No.:

#4

Size:

ca. 5.6 mm

Distribution:

ca. 13.13 %

No.:

#3

Size:

ca. 8 mm

Distribution:

ca. 4.88 %

No.:

#2

Size:

ca. 11.2 mm

Distribution:

ca. 0.14 %

No.:

#1

Size:

ca. 16 mm

Distribution:

ca. 0 %

Conclusions:

The particle size distribution of the dry weak dispersion test method GRADIS/L showed, that the particle, as they exist, were agglomerated and the distribution of the particles were very large. The particles larger than 1400 μm could have been measured because either the asymmetric particles fell through the 1400 μm sieve at a certain angle and were detected by the laser in the measurement, or some smaller particles could have been detected as one larger particle due to clumping or agglomeration. The particle size distribution of the dry intense dispersion test method RODOS/L showed, that the particles were dispersed by the dispersion pressure to smaller particles. But the particle size became only slightly smaller with increasing dispersion pressure. Thus, one can say that the particles were quite robust and were already relatively strongly dispersed with weak dispersion pressure. The small change in particle size with increasing dispersion pressure could have been caused by dispersion or particle destruction.

Executive summary:

The study was performed to determine the Particle size of the test substance. The particle size was determined by sieving until a particle size of 1.4 mm and the particles lower than 1400 μm were determined by laser diffraction according to OECD Test Guideline 110 (1981) and ISO 13320 (2009).The particle sizes lower than 1.40 mm were determined by laser diffraction.

A range of the median particle size D50 = 280.89 – 499.99 μm at the dispersion method GRADIS/L was determined. Afterwards a range of the median particle size D50 = 44.45 – 49.71 μm at the dispersion method RODOS/L with a dispersion pressure 1 bar and a range of the median particle size D50 = 40.59 – 41.23 μm at the dispersion method RODOS/L with a dispersion pressure 2 bar were determined. The range of the particle size distribution was calculated by 3 singular measurements. The particle size of the test method GRADIS/L showed most closely the particles how they exist. The test method RODOS/L showed how the particles behaved under pressure (1 bar and 2 bar) and thus probably the lowest possible particles. The particle size distribution of the dry weak dispersion test method GRADIS/L showed, that the particle, as they exist, were agglomerated and the distribution of the particles were very large.

Description of key information

The registered item is a powder where approximately 36% is less than 1.40 mm.  Of that 36%,  10% of the particles are approximately ≤ 39 µm (i.e., 3.6% ≤ 39 µm), 50% are ≤ 500 µm (i.e., 18% are ≤ 500 µm), and 90% are ≤ 2141 µm (i.e., 32.4% are ≤ 2141 µm).