Reaction mass of [3-(trimethoxysilyl) propyl]urea, [3-(dimethoxyethoxysilyl) propyl]urea, [3-(methoxydiethoxysilyl) propyl]urea and [3-(triethoxysilyl) propyl]urea.

Boiling point

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling point/boiling range)

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

GLP compliance:

yes

Type of method:

differential scanning calorimetry

Decomposition:

ambiguous

Decomp. temp.:

ca. 150 °C

Remarks on result:

other: No boiling temperature observed

Details:

The heat flow curves show an imprecisely reproducible and very noisy endothermic peak with a flat, broad shape, not characteristic for a boiling point. Reweighing after the measurement the sample had lost only approximately 20% of its mass. The extrapolated onset temperature of 154°C can therefore not be regarded as the boiling temperature of the sample. At best it characterises the beginning evaporation of the most volatile components of the test substance, possibly associated with decomposition.

Conclusions:

No boiling temperature could be determined in a reliable study conducted according to an appropriate test protocol, and in compliance with GLP.

Reference 2

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 Jun 1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling point/boiling range)

GLP compliance:

yes

Type of method:

differential scanning calorimetry

Decomposition:

yes

Decomp. temp.:

> 270 °C

Remarks on result:

other: No boiling temperature observed.

Remarks on result:

other: > 150°C evaporation of volatile components

Details:

DSC curve for first experiment:

An endothermic effect was observed above about 150°C (423 K). The maximum of this effect was observed at about 263°C (536 K). Above this temperature the effect decreased and changed to exothermic. After the experiment the sample appeared to have lost 23.22 mg (83%) of its mass. The residue was a brown to black solid (the original sample was a colourless liquid).

DSC curve for second experiment:

At temperatures above about 150°C (423 K) an endothermic effect was observed. Above about 276°C (549 K) the effect changed to exothermic. The sample lost 18.72 mg (42%) of its mass during this experiment. The residue was a brown to black solid.

Conclusion

Boiling of the test substance was not observed. The endothermic effects, observed above about 150°C (423 K) are probably caused by evaporation of part of the test substance (volatile components). The boiling point is probably not reached because the composition of the test substance changes. At higher temperatures, above about 270°C (523 K) the endothermic effect decreases and changes to exothermic. This indicates reaction or decomposition of the test substance.

Conclusions:

No boiling temperature could be determined in a reliable study conducted according to an appropriate test protocol, and in compliance with GLP.

Description of key information

> 150°C evaporation of volatile components
> 270°C decomposition

Additional information

No boiling temperature could be determined by Differential Scanning Calorimetry according to OECD Guideline 103. At temperatures > 150°C the evaporation of volatile components was observed and the substance decomposes at temperatures > 270°C. This result was supported by another DSC study according to OECD Guideline 103. The endothermic peak with onset of ca. 150°C in the DSC was interpreted as the beginning evaporation of the most volatile components, possibly associated with decomposition.