Naphthenic acids, cobalt salts

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:

2009-11-23 to 2009-11-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

no

Type of method:

thermal analysis

Remarks:

differential scanning calorimetry (DSC)

Atm. press.:

>= 1 000 - <= 1 004 hPa

Decomposition:

yes

Decomp. temp.:

75 °C

Remarks on result:

other: based on DSC-measurement, performed under nitrogen; discolouring of the sample at 67 °C; test item starts melting under decomposition at 75 °C to 117 °C.

Thermal Stability:

The DSC-measurement (prepared at 1000 hPa) in a closed glass crucible with the test item showed no endothermic or exothermic effects up to 400 °C.

Melting Point / Melting Range (DSC):

The measurements in aluminium crucibles (measured at 1000 hPa and 1004 hPa respectively) with a hole under nitrogen showed one endothermic effect in the temperature range 70 – 295 °C (onset temperature of 108°C).

Due to the optical inspection, the results from the DSC-measurements and the results from the capillary method it can be concluded that the test item starts melting under decomposition at 75 °C to 117 °C.

Conclusions:

The test item, cobalt(II) naphthenate, starts to melt under decomposition at 75 °C. A discolouring of the sample is observed at 67 °C.

Description of key information

No melting point can be stated. Naphthenic acids, cobalt salts starts to melt under decomposition at 75 °C.

Additional information

The melting point of the test substance was determined according to OECD guideline 102 with the differential scanning calorimetry method (DSC). The test item was heated up from ambient to the final temperature (600 °C and 300 °C respectively) at a constant heating rate (10 K/min) in a defined atmosphere (nitrogen). The quantity of heat absorbed or released was measured and recorded. Aluminium crucibles with a small hole were used as containers for the test item and as empty reference crucible.

A measurement in a capillary tube in a metal block was used to clarify the results from the DSC-measurement. The maximum temperature of this equipment is limited to 400 °C. Set point and maximum temperature were chosen according to the results of the DSC measurements.

The results of the optical inspection, of the DSC-measurements and of the capillary method showed that naphthenic acids, cobalt salts starts to melt under decomposition at 75 °C to 117 °C.