Hexasodium 2,2'-[vinylenebis[(3-sulphonato-4,1-phenylene)imino[6-[(2-cyanoethyl)[2-(2-hydroxyethoxy)ethyl]amino]-1,3,5-triazine-4,2-diyl]imino]]bis[benzene-1,4-disulphonate]

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:

January from the 16th to the 30th, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

1995

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Remarks:

and capillary method

Decomposition:

yes

Decomp. temp.:

280 °C

The test item showed abroad endothermic effect starting at a temperature of approx. 55 °C, a second broad endothermic effect starting at a temperature of approx. 280 °C and a third broad endothermic effect starting at a temperature of approx. 429 °C. No further endothermic or exothermic effect was observed up to a temperature of 500 °C.

Sample weight / mg	Onset of Effect / °C	Energy / (J/g)	Weight loss / mg	Atmospheric pressure / hPa
8.35	65.8 280.1 428.5	+240 +30 +90	3.94	982
5.08	54.8 279.8 429.1	+240 +30 +100	2.34	990

To verify the results of the DSC measurement, three additional measurements by the capillary method (Apparatus: Stuart Melting Point SMP30) were performed in the temperature range of 25 – 400 °C with a heating rate of 10 K/min.

While heating the test item, its structure became crystalline and liquid formed at the opening of the capillary. In view of this observation, the broad endothermic effect starting at 55 °C in the DSC measurements with open crucibles is probably caused by the simultaneous phase change of the test item, separation of liquid water from the test item and evaporation of that water. Anyway, this endothermic effect cannot be assigned to the melting of the test item.

Starting at a temperature of approx. 320 °C the test item became brown but did not liquefy. So the second broad endothermic effect also cannot be assigned to the melting of the test item. Even though the DSC measurements performed using the open aluminium crucibles did not show an exothermic effect, the observation made during the measurements by the capillary method suggest that the test item starts to decompose at a temperature of 320 °C.

Conclusions:

The test item decomposes before melt, starting at a temperature of approx. 280 °C.

Executive summary:

The melting temperature of the test substance was investigated using the Differential Scanning Calorimetry method and results were confirmed by the capillary method. The procedures used in the study were in accordance with OECD Test Guideline No.102. 

The test item showed abroad endothermic effect starting at a temperature of approx. 55 °C, a second broad endothermic effect starting at a temperature of approx. 280 °C and a third broad endothermic effect starting at a temperature of approx. 429 °C. No further endothermic or exothermic effect was observed up to a temperature of 500 °C. To verify the results of the DSC measurement, three additional measurements by the capillary method (Apparatus: Stuart Melting Point SMP30) were performed in the temperature range of 25 – 400 °C with a heating rate of 10 K/min. While heating the test item, its structure became crystalline and liquid formed at the opening of the capillary. In view of this observation, the broad endothermic effect starting at 55 °C in the DSC measurements with open crucibles is probably caused by the simultaneous phase change of the test item, separation of liquid water from the test item and evaporation of that water. Anyway, this endothermic effect cannot be assigned to the melting of the test item.

Starting at a temperature of approx. 320 °C the test item became brown but did not liquefy. So the second broad endothermic effect also cannot be assigned to the melting of the test item. Even though the DSC measurements performed using the open aluminium crucibles did not show an exothermic effect, the observation made during the measurements by the capillary method suggest that the test item starts to decompose at a temperature of 320 °C.

 

Conclusion

The test item decomposes before melt, starting at a temperature of approx. 280 °C.

Description of key information

The test item decomposes before melt, starting at a temperature of approx. 280 °C.

Additional information

OECD 102 - DSC and capillary methods