Registration Dossier

Physical & Chemical properties

Melting point / freezing point

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
melting point/freezing point
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2015-03-05 to 2015-03-06
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 102 (Melting point / Melting Range)
Version / remarks:
adopted on 27 July 1995
Qualifier:
according to
Guideline:
EU Method A.1 (Melting / Freezing Temperature)
Version / remarks:
Council Regulation (EC) No 440/2008 of 30 May 2008
Qualifier:
according to
Guideline:
other: DIN EN ISO 3146:2002-06 Plastics
Version / remarks:
Determination of melting behaviour (melting temperature or melting range) of semi-crystalline polymers by capillary tube and polarizing-microscope methods
GLP compliance:
yes (incl. certificate)
Type of method:
capillary method
Key result
Decomposition:
yes
Remarks on result:
other: The measuring device used for the capillary method did not allow to check the course of the test by direct visual observation. But the observations after the end of the test supported the assumption that the test item had changed.

Visual observations

Before the measurements the test item was a white solid. After the test the samples looked clear and slightly beige. Also, inside the capillaries the test item was nothomogeneouslydistributed but some gaps (possibly due to gas generation) could be observed.

 

Melting temperature [°C]

First run

67.4

Second run

66.1

Third run

61.3

Mean value

65.0

Standard deviation

3.2

Discussion 

In general, it had to be concluded that no melting occurred but probably decomposition. This was based on the following point:

 

  • In parallel to the tests presented in this report,differential scanning calorimetry (DSC) measurements were performed (AQura GmbH,AN-ASB 0669.1; 2015) to determine the melting point of the test item with a second method. These experiments clearly showed that no melting occurred before decomposition. 
  • The measuring device used for the capillary method did not allow to check the course of the test by direct visual observation. But the observations after the end of the test supported the assumption that the test item had changed.
  • The single values measured varied relative widely with a high standard deviation.
Conclusions:
No melting point could be observed, probably decomposition of the substance occured.
Executive summary:

The melting/freezing temperature of the substance was determined according to OECD guideline no. 102 [adopted on 27 July 1995] and EU test method A.1 [Council Regulation (EC) No 440/2008] with the capillary method. No melting point could be observed in the tested temperature range; probably decomposition of the substance occurred.

Endpoint:
melting point/freezing point
Remarks:
DSC method
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2015-02-18 to 2015-03-02
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 102 (Melting point / Melting Range)
Version / remarks:
adopted on 27 July 1995
Qualifier:
according to
Guideline:
EU Method A.1 (Melting / Freezing Temperature)
Version / remarks:
Council Regulation (EC) No 440/2008 of 30 May 2008
GLP compliance:
yes (incl. certificate)
Type of method:
differential scanning calorimetry
Remarks:
with preliminary thermogravimetric measurement
Key result
Decomposition:
yes
Decomp. temp.:
>= 150 °C
Remarks on result:
other: No melting point could be observed

A preliminary thermogravimetric measurement was performed over a temperature range from room temperature to approx. 600 °C. Several mass loss steps were registered with a total mass loss of 77.2 %, including the mass loss during initial purging with nitrogen (0.4 %). The residue was probably not pure inorganic but also organic material. 

The course of the thermographic curve indicates no melting but decomposition of the test item.

The residue looked black and foamy, coming through the hole of the crucible.

Two DSC measurements were performed in the temperature range from 20 – 250 °C, since the thermogravimetric test had shown evidence for decomposition starting at approx. 150 °C. The course of the heat flow curves confirmed the results of the thermogravimetric measurement. No sharp endothermic peak indicating a melting point could be observed.

Reweighing after the measurement showed that the sample had lost approx. 11.0 / 12.2 % of its mass. The remaining residues looked dark-brown and foamy, coming through the hole of the crucible.

Conclusions:
No melting point was observed, but decomposition starting at approximately 150 °C.
Executive summary:

The melting temperature of the test item was determined by differential scanning calorimetry according to OECD Test Guideline 102 [adopted on 27 July 1995] and EU test method A.1 “Melting/freezing temperature”, Council Regulation (EC) No 440/2008 of 30 May 2008 at atmospheric pressure.

The course of the thermographic curve indicated no melting point but decomposition of the test item. The residue looked black and foamy, coming through the hole of the crucible. A preliminary thermogravimetric test had shown evidence for decomposition starting at approx. 150 °C.

No melting point could be observed until decomposition started at approximately 150 °C.

Description of key information

No melting point could be observed until decomposition started at approximately 150 °C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:
150 °C

Additional information

The melting point of Sophorolipids was determined by two different methods, i.e. by the capillary method as well as by the DSC method. In both cases no melting point could be observed. Instead, decomposition at a temperature of ca. 150 °C occurred as observed in the DSC measurement.

In conclusion, no melting point could be observed until decomposition started at approximately 150 °C.