Registration Dossier

Administrative data

Endpoint:
melting point/freezing point
Type of information:
experimental study
Adequacy of study:
key study
Study period:
18th November-25th November 1997
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: A well described thermal analytical result (TG/DTA and DSC). No details on the test sample, only batch name was given. No GLP study.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method A.1 (Melting / Freezing Temperature)
Principles of method if other than guideline:
No guideline is mentioned in the report but the study is very well described and performed according to EC A.1 test guideline.
GLP compliance:
no
Type of method:
thermal analysis

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Crystal form. No further details on the test material were given in the document.

Results and discussion

Melting / freezing point
Decomposition:
yes
Decomp. temp.:
>= 224 °C
Remarks on result:
other: Decomposition at >= 497 K. No melting or boiling temperature.

Any other information on results incl. tables

TG/DTA results.

Under Oxygen:

Vigorous decomposition (significant exothermic effect)

Ttop: 240.5°C; Tonset: 238.3°C (delta H= -693 uV.s/mg)

Weight loss: 0.05% until 230°C (evaporation of small amount of volatile components) and 36.8% (decomposition)

Results under Nitrogen:

Decomposition (exothermic) but less vigorous than under oxygen.

Ttop: 240.5°C; Tonset: 224.3°C (delta H= -94 uV.s/mg)

Weight loss: 0.24% until 230°C (evaporation) and 42.1% (decomposition)

Differential Scanning Calorimetry (DSC) results:

Sealed cup:

Ttop: 230.1°C, Tonset: 227.7°C. deltaH= -400.2 mJ/mg ; deltaH= -16.1 mJ/mg

Open cup:

Before decomposition, a small transition effect was observed. This might be due to the presence of a minor component (e.g. volatile component). The second (large exothermic) effect is due to decomposition.

From the curve it was concluded that decomposition occurs in several steps. This was not observed in the sealed cup. Probably, some oxygen was in the sealed cup and decomposition reaction in it is more vigorously than in the open cup.

Exothermic decomposition occurs at lower temperatures in sealed containers. The amount of energy released during decomposition is much higher in sealed containers than in open containers.

First transition: Ttop64.6°C (delta H= 14.8 mJ/mg)

Second transition: Tonset: 225.6°C (delta H= -163.7 mJ/mg); Ttop:240.6°C

Applicant's summary and conclusion

Conclusions:
Reaction and/or decomposition of the test substance was observed at temperatures of >= 224°C (> 497 K). In an oxygen atmosphere, decomposition is vigorous. Melting and/or boiling of the test substance was not observed below the temperature at which reaction and/or decomposition started. Based on this, the test substance has no melting and/or boiling temperature.