1,1'-(methylenedi-4,1-phenylene)bis(3-butylurea)

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993-11-23 to 1994-03-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

EEC 92/69

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

1981

Deviations:

no

GLP compliance:

yes

Type of method:

static method

Specific details on test material used for the study:

Analytical purity: >= 99.65 %
Lot/batch No.: 93.166

Key result

Temp.:

20 °C

Vapour pressure:

< 0 Pa

Results

Vapour pressures are presented in the table below. This shows a rise in vapour pressure up to 145 °C. To confirm the result, the sample was re-evacuated and allowed to reach equilibrium again and the vapour pressure determined. This was repeated three times, and the background pressure was determined and subtracted from the vapour pressure. There was no evidence of sample decomposition at the end of the vapour pressure determination.

 

	Temperature °C	Pressure Pa
	34.8	0.0931
	47.5	0.1197
	69.8	0.1330
	89.2	0.1862
	119.9	0.2128
	144.9	0.2793
	146.7	0.0532
	146.6	0.0532
	147.7	0.0665
Mean values of the previous three results	147.0	0.0576
Background pressure	150.0	0.0399

 

The mean vapour pressure and mean temperature from the last three readings is 147.0 °C and 0.058 Pa, and subtracting the background pressure gives a vapour pressure of 0.018. Since it was not possible to construct a vapour pressure versus temperature plot, an extrapolation to 20 °C was made using the assumption that the slope of the curve is -2000. This is a reasonable assumption, since for solids this is the minimum figure normally seen. From this, the intercept can be calculated in the Clausius-Clapeyron equation, and this equation used to calculate vapour pressure at 20 °C:

Log(0.018) = -2000 x (1/420.15) + C
C = 3.02
Log (VP) = -2000 x (1/293.15) + 3.02

The vapour pressure calculated by this method was below 1.6E-04 Pa at 20 °C.

Conclusions:

The vapour pressure of HAT ISO was measured with a static method according to EU Guideline A 4. The vapour pressure of HAT ISO determined by this method was below 1.6 x 10E-4 Pa at 20 °C.

Executive summary:

Results

Vapour pressures are presented in the table below. This shows a rise in vapour pressure up to 145 °C. To confirm the result, the sample was re-evacuated and allowed to reach equilibrium again and the vapour pressure determined. This was repeated three times, and the background pressure was determined and subtracted from the vapour pressure. There was no evidence of sample decomposition at the end of the vapour pressure determination.

 

	Temperature °C	Pressure Pa
	34.8	0.0931
	47.5	0.1197
	69.8	0.1330
	89.2	0.1862
	119.9	0.2128
	144.9	0.2793
	146.7	0.0532
	146.6	0.0532
	147.7	0.0665
Mean values of the previous three results	147.0	0.0576
Background pressure	150.0	0.0399

 

The mean vapour pressure and mean temperature from the last three readings is 147.0 °C and 0.058 Pa, and subtracting the background pressure gives a vapour pressure of 0.018. Since it was not possible to construct a vapour pressure versus temperature plot, an extrapolation to 20 °C was made using the assumption that the slope of the curve is -2000. This is a reasonable assumption, since for solids this is the minimum figure normally seen. From this, the intercept can be calculated in the Clausius-Clapeyron equation, and this equation used to calculate vapour pressure at 20 °C:

Log(0.018) = -2000 x (1/420.15) + C
C = 3.02
Log (VP) = -2000 x (1/293.15) + 3.02

The vapour pressure calculated by this method was below 1.6E-04 Pa at 20 °C.

Description of key information

The vapour pressure of HAT ISO was measured with a static method according to EU Guideline A 4. The vapour pressure of HAT ISO determined by this method was below 1.6E-04 Pa at 20 °C (293.15 K).

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

20 °C