4,4,13,13-tetraethoxy-3,14-dioxa-8,9-dithia-4,13-disilahexadecane

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:

1998-03-20 to 1998-03-23

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The study was conducted according to an appropriate EU test method but was not compliant with GLP.

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

92/69/EWA

GLP compliance:

no

Type of method:

differential scanning calorimetry

Key result

Remarks on result:

other: No melting/freezing observed when the sample was heated between 25°C to -140°C, but glass transition was observed at around -117°C.

Cooling down the 10.52 mg-sample from 25°C to -140°C with a cooling rate of 2K/min no endothermic crystallisation (first-order transition) can be seen, but a weak glass transition (second-order transition) at -117.5°C (extrapolated onset) and -119.3°C (glass transition temperature) was observed. On heating up the frozen sample from -140°C to 0°C, no endothermic melting ( transition from solid crystalline state to the liquid state) was observed, but now a strong glass transition at -118.6°C ( extrapolated onset) and -117.5°C (glass transition temperature) occured. After cooling a second time to -140°C and once more heating, the glass transition was seen at -118.2°C resp. -117.4°C.

 

The 10.01 mg sample showed a glass transition at -117.1°C (extrapolated onset) resp. -116.4°C (glass transition temperature).

 

The thermograms are attached.

Conclusions:

In a reliable study conducted according to EU Method A.1 (Melting/Freezing Point) Differential Scanning Calorimetry, the substance did not melt but underwent a glass transition with an extrapolated onset temperature of ca. -118°C and a glass transition temperature of ca. -117°C.

Description of key information

Melting point: < -20°C at 1013 hPa (EU Method A.1)

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

-20 °C

Additional information

In a reliable study conducted according to EU Method A.1 (Melting/Freezing Point) using Differential Scanning Calorimetry (DSC) method, the sample was cooled between 25°C and -140°C; the substance did not melt but underwent a glass transition with an extrapolated onset temperature of ca. -118°C and a glass transition temperature of ca. -117°C. No other reliable studies are available, so this is considered the key result.

 

A pour point of approximately -35°C at 1013 hPa and a melting point of approximately -80°C at 1013 hPa were reported in secondary sources to which reliability could not be assigned.

 

The available data are considered sufficient to indicate that the melting/freezing point of the submission substance is below the threshold of -20°C specified in Column 2 of REACH Annex VII.