Disodium 5,5'-[(1-methylethylidene)bis(4,1-phenyleneoxysulphonyl-2,1-phenyleneazo)]bis[6-aminonaphthalene-1-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:

07 November 2018 to 04 December 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Specific details on test material used for the study:

Test item: Acid Orange 94 Refined
Alternative name: Disodium 5, 5’-[(1-methylethylidene)bis(4,1-phenyleneoxysulphonyl-2,1-phenyleneazo)]bis[6-aminonaphthalene-1-sulphonate]
CAS number: 70161-18-1
EC number: 274-354-1
Intended use: Industrial chemical
Appearance: Reddish brown crystals
Storage conditions: Room temperature (10 – 30C), in the dark
Lot number: 8009
Expiry/Retest date: 31 December 2019
Purity: 97%

Key result

Decomposition:

yes

Decomp. temp.:

176 °C

Remarks on result:

other: s the test item decomposed, no value for melting point could be determined.

As a result of the initial low rate of enthalpy change during decomposition, the onset temperature could only be approximated. From the thermograms there appeared to be some mild decomposition from around 180 °C and up to around 280 °C. This was accompanied with less than 5% in loss of the original weight. However, from around 280 °C the thermograms demonstrated that decomposition increased and caused another approximately 30% weight loss.

Similar thermographic profiles were obtained using air and nitrogen atmospheres. This suggested that the decomposition was probably thermal and not oxidative.

Conclusions:

The test item was determined to decompose from approximately 176 °C (449 K). As the test item decomposed, no value for melting point could be determined.

Executive summary:

The melting point was determined using differential scanning calorimetry according to the OECD 102 guideline in accordance with GLP. The test item was determined to decompose from approximately 176 °C (449 K). As the test item decomposed, no value for melting point could be determined

Description of key information

The melting point was determined using differential scanning calorimetry according to the OECD 102 guideline in accordance with GLP. The test item was determined to decompose from approximately 176 °C (449 K). As the test item decomposed, no value for melting point could be determined

Additional information

As a result of the initial low rate of enthalpy change during decomposition, the onset temperature could only be approximated. From the thermograms there appeared to be some mild decomposition from around 180 °C and up to around 280 °C. This was accompanied with less than 5% in loss of the original weight. However, from around 280 °C the thermograms demonstrated that decomposition increased and caused another approximately 30% weight loss.

Similar thermographic profiles were obtained using air and nitrogen atmospheres. This suggested that the decomposition was probably thermal and not oxidative.