Naphthalenesulfonic acid, di-C9-rich C8-10-branched alkyl derivs., calcium salts

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Start : 19 March 2012 Completion : 20 July 2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP study without deficiencies. Barium bis( di C8-C10, branched, C9 rich, alkylnaphthalene sulphonate) is a close structural analog and the data are acceptable as read-across.

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

thermal analysis

Decomposition:

yes

Decomp. temp.:

>= 325 °C

Remarks on result:

other: No melting temperature. Reaction and/or decomposition of the test substance was observed starting at 325°C

An exothermic peak between 325°C and 350°C was observed. The effect was due to reaction and/or decomposition of the test substance. After the experiment, a brown/black molten residue remained in the sample container. To investigate melting of the test substance a lower start temperature was applied in experiment II. No effects were observed which were due to melting of the test substance. After the experiment, a brown/black molten residue remained in the sample container. To investigate melting during reaction and/or decomposition, experiment III was stopped at 325°C. No effects were observed which were due to melting of the test substance. After the experiment, a brown/black partially molten residue remained in the sample container. The test substance is a powder with lumps. After experiment III, the lumps were still visible but the powder had been coagulated. It was assumed that melting occurs after decomposition has taken place and that therefore the test substance has no melting point.

Conclusions:

The melting and boiling temperature of Barium bis( di C8-C10, branched, C9 rich, alkylnaphthalene sulphonate) were determined using DSC.
Reaction and/or decomposition of the test substance was observed at temperatures of > 325°C (> 598K). Boiling of the test substance was not observed below this temperature. Based on this, the test substance has no melting and/or boiling temperature.

Executive summary:

The melting temperature of Barium bis( di C8-C10, branched, C9 rich, alkylnaphthalene sulphonate) was determined using differential scanning calorimetry (DSC). This technique records the difference in heat flow to two crucibles, one filled with test substance and the other left empty as reference, while these crucibles are subjected to a controlled temperature programme. When the test substance undergoes a transition, such as melting or evaporation, it is indicated by a deviation from the base line of the heat-flow record. Because melting and evaporation are processes in which heat is consumed, for these processes the deviation from the base line is in the endothermic direction. The melting temperature or boiling temperature (if any) of the test substance is evaluated from the DSC curve as the extrapolated onset temperature of the endothermic melting or evaporation peak.

An exothermic peak between 325°C and 350°C was observed. The effect was due to reaction and/or decomposition of the test substance. After the experiment, a brown/black molten residue remained in the sample container. To investigate melting of the test substance a lower start temperature was applied in experiment II. No effects were observed which were due to melting of the test substance. After the experiment, a brown/black molten residue remained in the sample container. To investigate melting during reaction and/or decomposition, experiment III was stopped at 325°C. No effects were observed which were due to melting of the test substance. After the experiment, a brown/black partially molten residue remained in the sample container. The test substance is a powder with lumps. After experiment III, the lumps were still visible but the powder had been coagulated. It was assumed that melting occurs after decomposition has taken place and that therefore the test substance has no melting point.

Reaction and/or decomposition of the test substance was observed at temperatures of > 325°C (> 598K). Based on this, the test substance has no melting temperature.

Description of key information

Melting point is determined from read-across from the close analog Barium bis( di C8-C10, branched, C9 rich, alkylnaphthalene sulphonate) (Barium DNNSA). The melting and boiling temperature of Barium DNNSA were determined using DSC. Reaction and/or decomposition of the test substance was observed at temperatures of > 325°C (> 598K). Boiling of the test substance was not observed below this temperature. Based on this, the test substance has no melting and/or boiling temperature.