Reaction mass of octan-2-ylbenzene, octan-3-ylbenzene and octan-4-ylbenzene

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:

17 june 2019 - 04 July 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

2016

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

Principles of method if other than guideline:

No freezing point could be determined by DSC. Therefore an additional experiment was performed in which the consistency of the substance was determined by visual observation after samples had been placed at approx. -20°C and -80°C. The additional experiment is not a guideline study but was described in sufficient detail in the study report.

GLP compliance:

yes

Type of method:

other: differential scanning calorimetry and storage in freezer

Key result

Melting / freezing pt.:

< -83.3 °C

TGA EXPERIMENT (PRELIMINARY TEST)

Decrease of weight from 150°C upwards: 25% at 221°C and 70% at 245°C.

After the experiment it was observed that the test item was evaporated from the sample container.

 

DSC EXPERIMENT 1

During cooling, no effects were observed. During heating an endothermic effect was observed between 150°C and 275°C. The extrapolated onset temperature of the effect was 240.331°C. The endothermic effect was most likely obtained due to boiling of the test item because after the experiment it was observed that the test item had evaporated from the sample container.

DSC EXPERIMENT 2

In order to investigate the endothermic effect, a higher heating rate of 50°C/minute was used in the Experiment 2. The extrapolated onset temperature was 247.685°C. The endothermic effect had not shifted to higher temperatures. It demonstrated that boiling of the test item caused the endothermic effect. After the experiment it was observed that the test item had evaporated from the sample container. Since a higher heating rate was used, the extrapolated onset temperature was not used in the calculation of the boiling point.

DSC EXPERIMENT 3

Experiment 3 was performed with the same heating rate as in Experiment 1. Similar results as in Experiment 1 were obtained. The extrapolated onset of the boiling effect was 245.935°C. The difference in the extrapolated onset between Experiment 1 and 3 was > 1°C. After the experiment it was observed that the test item had evaporated from the sample container. Since in experiment 2 and 3 no cooling cycle was applied, the test item might have been evaporated during the heating cycle. Therefore, another experiment was performed with the same conditions as experiment 3.

DSC EXPERIMENT 4

Experiment 4 was performed as a duplicate of Experiment 3. Heating rate was the same as in Experiment 1 and Experiment 3. The extrapolated onset of the boiling peak was 245.714°C. After the experiment it was observed that the test item had evaporated from the sample container.

DSC curves: see Illustration below.

STORAGE IN FREEZER

After storage in a freezer (-20.8 ± 1.7°C) for 41 hours, the test item was observed to be a liquid.

After storage in freezer (-83.3 ± 1.9°C) for 41 hours, the test item was observed to be a viscous liquid.

DATA HANDLING

Boiling temperature: the mean extrapolated onset temperature of DSC Experiment 3 (245.9°C) and DSC Experiment 4 (245.7°C).

 

Conclusions:

The substance has no melting/freezing point at temperatures down to -83.3°C.

Executive summary:

Differential Scanning Calorimetry was performed to determine the melting and boiling temperature. The experiments were based on EC A.1, OECD 102 and OPPTS 830.7200 (melting temperature) and on EC A.2, OECD TG 103 and OPPTS 830.722 (boiling temperature). GLP-study. There was no DSC effect due to melting/freezing of the liquid substance between 25°C and -90°C. The boiling temperature was determined to be 245.8°C at 1014 hPa (mean of duplicate experiments). An additional non-guideline experiment 'Storage in freezer' was performed. Additional samples were placed at -20.8 ± 1.7°C and -83.3 ± 1.9°C for 41 hours, both resulting in liquid forms. From this it was concluded that the substance has no melting/freezing point at temperatures down to -83.3°C.

Description of key information

No melting/freezing point down to -83.3°C (visual observation and DSC experiment, EC A.1, OECD 102, OPPTS 830.7200).

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

-83.3 °C

Additional information

DSC showed no effect due to freezing of the substance between 25°C and -90°C. After storage in freezers, the substance was visually observed to be a liquid at ca. -20°C and a viscous liquid at ca. -80°C.