Disodium 3,3'-[carbonylbis[imino(3-methoxy-4,1-phenylene)azo]]bis[benzenesulphonate]

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental starting date: 28 April 2017; Experimental completion date: 03 November 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Test material

Test material information

Constituent 1

Reference substance name:

Disodium 3,3'-[carbonylbis[imino(3-methoxy-4,1-phenylene)azo]]bis[benzenesulphonate]

EC Number:

233-316-4

EC Name:

Disodium 3,3'-[carbonylbis[imino(3-methoxy-4,1-phenylene)azo]]bis[benzenesulphonate]

Cas Number:

10114-86-0

Molecular formula:

C27H22N6Na2O9S2

IUPAC Name:

disodium 3,3'-[carbonylbis[imino(3-methoxy-4,1-phenylene)azo]]bis[benzenesulphonate]

Test material form:

solid: particulate/powder

Details on test material:

Identification: CIM-42(Direct Yellow 132)
Appearance/physical state: dark orange colored powder
Batch: 161011K
Purity: 94.0%
Expiry / Retest date: 01 December 2017
Storage conditions: Room temperature, in the dark over silica

Results and discussion

Melting / freezing point

Key result

Decomposition:

yes

Decomp. temp.:

ca. 347 °C

Sublimation:

no

Any other information on results incl. tables

Thermographic data for Determinations 1 to 4 are shown in the following table:

Determination	Thermal Event	Interpretation	Temperature
			ºC	K
1	Approximate exotherm onset temperature.	Approximate onset of decomposition.	346.82	620
	Extrapolated exotherm onset temperature.	Extrapolated onset of decomposition.	373.30	646
2	Approximate exotherm onset temperature.	Approximate onset of decomposition.	349.12	622
	Extrapolated exotherm onset temperature.	Extrapolated onset of decomposition.	372.88	646
3	Approximate exotherm onset temperature.	Approximate onset of decomposition.	347.00	620
	Extrapolated exotherm onset temperature.	Extrapolated onset of decomposition.	372.56	646
4	Approximate exotherm onset temperature.	Approximate onset of decomposition.	349.59	623
	Extrapolated exotherm onset temperature.	Extrapolated onset of decomposition.	372.51	646

 

Overall result:            The test item decomposed from approximately 347 °C (620 K)

Discussion:

As a result of the initial low rate of enthalpy change during decomposition, the onset temperature could only be approximated. To present a worst case scenario with respect to thermal stability, the lowest observed onset temperature has been reported as the overall result.

Similar thermographic profiles were obtained using air and nitrogen atmospheres. This indicated that the decompositionwas probably thermal and not oxidative.

The broad endotherm seen in all determinations at approximately 80 to 160 °C was attributed to the loss of residual moisture from the test item, with the Sponsor specifying 5.0% water content. Additional investigative evaluations performed up to maximum temperature of 200 °C confirmed that no phase transition (i.e. melting) of the test item was associated with this thermal event.

Applicant's summary and conclusion

Conclusions:

The test item was determined to decompose from approximately 347 °C (620 K). As the test item decomposed, no value for melting point could be determined.

Executive summary:

The test item was determined to decompose from approximately 347 °C (620 K) by a differential scanning calorimetry procedure designed to be compatible with Method A.1 Melting/Freezing Temperature of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 102 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.  As the test item decomposed, no value for the melting point could be determined.