Magnesium octadecylbenzenesulphonate

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:

18 March 2019 to 18 April 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Deviations:

no

GLP compliance:

yes

Type of method:

differential scanning calorimetry

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch No.of test material: E01255-297
- Expiration date of the lot/batch: 31 December 2022

Key result

Melting / freezing pt.:

>= 250 - <= 300 °C

Decomp. temp.:

> 300 - <= 400 °C

Remarks on result:

other: Part of the test item melts between 250-300 °C

Key result

Melting / freezing pt.:

> 300 °C

Decomp. temp.:

> 300 - <= 400 °C

Remarks on result:

other: One part of the test item melts >300 °C

In the preliminary test the weight of the sample decreased significantly at a starting temperature of 425 °C. At 467 °C the sample weight had decreased by 25 %. After the experiment a black molten residue remained in the sample container (original colour: brown). The change of the colour indicated reaction and/or decomposition of the test item.

As part of the main study, Experiment 1, an endothermic effect was observed between 25 °C and 225 °C. The endothermic effect was most likely obtained due to evaporation of volatile components (based on the weight loss observed between 50 °C and 200 °C during the preliminary test). After the experiment, a dark brown molten residue remained in the sample container (original colour: brown). Based on this visual observation, it was found that the test item had molten. The change of the colour demonstrated reaction and/or decomposition of the test item. No clear effects were observed that could be attributed to melting or decomposition of the test item.

To investigate melting of the test item, a repeated heating cycle was applied in Experiment 2. During cooling, between the two heating cycles, no effects were observed. The endothermic effect observed with the first heating was not found during the second heating, indicating that the effect was due to evaporation of volatile components. No effects were observed which were due to melting and/or crystallization of the test item. After the experiment, a brown coagulated residue remained in the sample container.

Experiment 3 was performed as a duplicate of Experiment 1; similar results as in Experiment 1 were obtained. After the experiment, a dark brown molten residue remained in the sample container.

For visual observation of melting of the test item, Experiment 4, 5 and 6 were stopped at 205 °C, 255 °C and 305 °C, respectively. After Experiment 4 and 5, the sample appeared to be unchanged i.e. no melting and/or decomposition were observed. After Experiment 6 a brown coagulated residue remained in the sample container.

To investigate melting of the test item between 200 °C and 300 °C, a repeated heating cycle was applied in the Experiment 7. During cooling, between the two heating cycles, no effects were observed. No effects were observed which were due to melting and/or crystallization of the test item. After the experiment, a brown coagulated residue remained in the sample container.

No clear effects were observed that could be attributed to melting or decomposition of the test item. Based on visual observations, a change in consistency was observed between 250 °C and 300 °C (partially molten (coagulated)) and also at temperatures >300 °C (molten). Based on these results, it was concluded that part of the test item melts between 250 °C and 300 °C and another part of the test item melts >300 °C. Reaction and/or decomposition was visually observed between 300 °C and 400 °C.

Conclusions:

The melting of the test item was determined by DSC. The melting temperature of a part of the test item was between 250 °C (523 K) and 300 °C (573 K). The melting temperature of another part of the test item was above 300 °C (above 573 K). Reaction and/or decomposition of the test item was observed between 300 °C (573 K) and 400 °C (673 K). Boiling of the test item was not observed below the temperature at which reaction and/or decomposition started.

Executive summary:

The study was performed based on procedures in the OECD Guideline 102 (Melting point / Melting Range); EU Method A.1 (Melting / Freezing Temperature); EPA OPPTS 830.7200 (Melting Point / Melting Range). The melting of the test item was determined by DSC. The melting temperature of a part of the test item was between 250 °C (523 K) and 300 °C (573 K). The melting temperature of another part of the test item was above 300 °C (above 573 K). Reaction and/or decomposition of the test item was observed between 300 °C (573 K) and 400 °C (673 K).

Description of key information

The study was performed based on procedures in the OECD Guideline 102 (Melting point / Melting Range); EU Method A.1 (Melting / Freezing Temperature); EPA OPPTS 830.7200 (Melting Point / Melting Range). The melting of the test item was determined by DSC.

No clear effects were observed that could be attributed to melting or decomposition of the test item. Based on visual observations, a change in consistency was observed between 250 °C and 300 °C (partially molten (coagulated)) and also at temperatures >300 °C (molten). Based on these results, it was concluded that part of the test item melts between 250 °C and 300 °C and another part of the test item melts >300 °C. Reaction and/or decomposition was visually observed between 300 °C and 400 °C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

250 °C