N,N''-(methyl-m-phenylene)bis[N',N'-dimethylurea]

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:

January 2003

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Principles of method if other than guideline:

Differential scanning calorimetry or DSC is a thermoanalytical technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature. Both the sample and reference are maintained at nearly the same temperature throughout the experiment.

GLP compliance:

not specified

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

>= 178 - <= 184 °C

Atm. press.:

101 325 Pa

The melting point of TDI-Urone was determined applying DSC. 7.4 mg test substance were put into a platen and heated up to 300°C. The onset (178°C) and the peak (185°C) of the endothermic heat fluxes were measured. The melting point is reported as the peak of the endothermic heat fluxes.

Conclusions:

The melting point of TDI-Urone is 185°C.

Executive summary:

The melting point of TDI-Urone was determined applying differential scanning calorimetry. The test protocol is equivalent to the guideline EU A.01. The test substance, 7.4 mg TDI-Urone, were put into a platen at room temperature and heated up to 300°C. The onset and the peak of the endothermic heat fluxes were reported. The onset of the endothermic heat flux is 178°C and reaches a peak at 185°C. According the guideline EU A.01 the melting point is the temperature at which the final stage of melting is reached. Therefore, the melting point of TDI-Urone is 185°C.

Description of key information

The melting point of TDI-Urone was determined according the guideline EU A.01 applying differential scanning calorimetry.

The melting range is 178°C - 184 °C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

181 °C

Additional information

There are three literature sources available reporting the melting point of TDI-Urone.

In the "Chemische Sicherheit Untersuchungsbericht: TDI Uron" the melting point of TDI-Urone was determined applying differential scanning calorimetry. The test protocol is equivalent to the guideline EU A.01. The onset of the endothermic heat flux is 178°C and reaches a peak at 185°C. According the guideline EU A.01 the melting point is the temperature at which the final stage of melting is reached. Therefore, the melting range of TDI-Urone is 178 °C - 184 °C.

In a German Patent describing the "Verfahren zur Herstellung von Trisubstituierten Harnstoffen" the melting point of TDI-Urone was reported to be between 182°C and 185°C.

Another data source reporting the melting point of TDI-Urone is the safety data sheet of TDI-Urone provided by Degussa AG which reports the melting point be between 180°C and 182°C.

As the experimental data in the "Chemische Sicherheit Untersuchungsbericht: TDI Uron" is most reliable this value is chosen for the CSR.