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Administrative data

Endpoint:
melting point/freezing point
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 09 June 2017 to 25 July 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report date:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
EU Method A.1 (Melting / Freezing Temperature)
Version / remarks:
2008
Deviations:
no
Qualifier:
according to guideline
Guideline:
OECD Guideline 102 (Melting point / Melting Range)
Version / remarks:
1995
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 830.7200 (Melting Point / Melting Range)
Version / remarks:
1998
Deviations:
no
GLP compliance:
yes
Type of method:
differential scanning calorimetry

Test material

Constituent 1
Chemical structure
Reference substance name:
Tributyl-2-thiourea
EC Number:
219-350-2
EC Name:
Tributyl-2-thiourea
Cas Number:
2422-88-0
Molecular formula:
C13H28N2S
IUPAC Name:
1,1,3-tributylthiourea
Test material form:
liquid
Details on test material:
- Name of test material (as cited in study report): Tri butyl thiourea
- Appearance: Clear pale to medium brown liquid
- Storage conditions: At room temperature
Specific details on test material used for the study:
liquid at room temperature

Results and discussion

Melting / freezing point
Key result
Atm. press.:
>= 1 004 - <= 1 006 hPa
Decomposition:
no
Remarks on result:
other: Glass transition point: -54.3°C. No melting point was determined.

Any other information on results incl. tables

DSC EXPERIMENT 1

During cooling, a glass transition peak between -80°C and -50°C was found. During heating, a glass transition was observed between -75°C and -25°C (inflection point: -54.313°C). An endothermic peak ( extrapolated onset temperature: 221.182°C) was observed between 100°C and 275°C. The endothermic effect was most likely obtained due to boiling of the test item. After the experiment it was observed that the test item had evaporated from the sample container. DSC curve: see picture below.

DSC EXPERIMENT 2

In order to investigate the boiling peak, a higher heating rate of 50°C/minute was used. Extrapolated onset temperature: 224.036°C. Since a higher heating rate was applied, the extrapolated onset temperature was not used for calculation of the boiling temperature. The endothermic peak had not shifted significantly to higher temperatures. It demonstrated that boiling of the test item caused the endothermic effect. 

DSC EXPERIMENT 3

Experiment 3 was performed as a duplicate of Experiment 1. Similar results as in Experiment 1 were obtained. Inflection point of the glass transition: -54.286°C. Extrapolated onset of the boiling peak: 224.208°C. After the experiment it was observed that the test item had evaporated from the sample container.

DSC EXPERIMENT 4

Since a high difference in boiling temperature was found between Experiment 1 and Experiment 3, a fourth experiment was performed. Extrapolated onset of the boiling peak: 223.261°C. After the experiment it was observed that the test item had evaporated from the sample container.

DATA HANDLING

The glass transition temperature was determined as the mean inflection point of Experiment 1 (-54.313°C) and Experiment 3 (-54.286°C).

Applicant's summary and conclusion

Conclusions:
The glass transition point was determined to be -54.3°C. Melting of the substance was not observed.

Executive summary:

Differential Scanning Calorimetry (DSC) experiments were performed in a GLP study according to EC A.1, OECD 102 and OPPTS 830.7200.

The glass transition temperature of the substance was determined in duplicate obtaining a mean value of -54.3°C. Melting of the substance was not observed.