Sodium 1-amino-9,10-dihydro-9,10-dioxo-4-[(2,2,4-trimethylcyclohexyl)amino]anthracene-2-sulphonate

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:

From January 03rd to March 06th, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

1995

Qualifier:

according to guideline

Guideline:

other: OECD Test Guideline 113 (Thermal Stability)

Version / remarks:

1981

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Remarks:

and capillary method

Decomposition:

yes

Decomp. temp.:

ca. 110 °C

MELTING - BOILING POINT

In the temperature range of 50 – 150 °C, an endothermic effect was observed, which may be caused by the drying of the test item (3.2 % water). Between 220 – 280 °C, a second endothermic effect could be detected. In the temperature range of 320 – 480 °C, a broad exothermic effect was observed.

No.	Sample weight / mg	Onset of effect / °C	Range of effect / °C	Weight loss / mg	Atmospheric pressure / hPa
Rep. 1	10.3	80.99	50 – 150 (endo)	6.91	994.1
		223.58	220 – 280 (endo)
		---	320 – 480 (exo)
Rep. 2	10.8	85.13	60 – 150 (endo)	7.49	994.1
		223.14	220 – 280 (endo)
		---	320 – 480 (exo)

CAPILLARY MEASUREMENT

To verify the results of the DSC measurement, an additional measurement with the capillary method was performed in the temperature range of 70 – 300 °C with a heating rate of 10 K/min. The test item showed no melting in the temperature range from 70 to 220 °C. At a temperature of 220 °C the colour of the test item partially changed to grey. Above 250 °C the test item liquefied under decomposition and an increase of volume of the test item and the colour changed to black.

Due to this result, the endothermic effect which was observed during the heating phase in the temperature range of 50 – 150 °C, cannot be associated with the melting of the test item.

The second endothermic signal in the temperature range of 220 – 280 °C can be associated with a liquefying under decomposition.

Due to this result, the test item shows no melting or boiling until the decomposition starting at a temperature of approx. 110 °C.

THERMAL STABILITY

In the temperature range of 110 – 240 °C an exothermic effect can be observed, with a maximum decomposition energy of -320 J/g.

No.	Sample weight / mg	Start / °C	Energy / J/g
Rep. 1	6.72	110 (exothermic)	-320
Rep. 2	8.01	120 (exothermic)	-240

Conclusions:

Decomposition before melting/boiling at ca 110 °C.

Executive summary:

The thermal behaviour of the substance was assessed in accordance with OECD guidelines 102 and 113.

The determination of the melting and boiling point of the test item was performed using Differential Scanning Calorimetry (DSC). The test item was weighed out into an aluminium crucible under air atmosphere; two tests were run. The temperature of the apparatus was up to 500 °C at a constant heating rate of 10 K/min under an inert atmosphere. In order to confirm the study outcomes, a second test was conducted using capillary method.

In addition, the thermal behaviour was further investigated placing the test item in a closed glass crucible. The determination of the thermal stability of a substance was performed via Differential Scanning Calorimetry (DSC), heating the apparatus from room temperature up to 500 °C, with a heating rate of 3 K/min. Two investigations were performed.

In the temperature range of 50 – 150 °C, an endothermic effect was observed, which may be caused by the drying of the test item (3.2 % water). Between 220 – 280 °C a second endothermic effect could be detected. In the temperature range of 320 – 480 °C, a broad exothermic effect was observed. To verify the results of the DSC measurement, an additional measurement with the capillary method was performed in the temperature range of 70 – 300 °C with a heating rate of 10 K/min. The test item showed no melting in the temperature range from 70 to 220 °C. At a temperature of 220 °C the colour of the test item partially changed to grey. Above 250 °C the test item liquefied under decomposition and an increase of volume of the test item and the colour changed to black. Due to this result, the endothermic effect, observed during the heating phase in the temperature range of 50 – 150 °C, cannot be associated with the melting of the test item.

The second endothermic signal in the temperature range of 220 – 280 °C can be associated with a liquefying under decomposition. Due to this result, the test item shows no melting or boiling until the decomposition starting at a temperature of approx. 110 °C. In the temperature range of 110 – 240 °C an exothermic effect can be observed, with a maximum decomposition energy of -320 J/g.

Conclusion

Decomposition before melting/boiling at ca 110 °C.

Description of key information

Decomposition before melting/boiling at ca. 110 °C.

Additional information

OECD 102/113 - Differential Scanning Calorimetry (DSC) and capillary methods