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Physical & Chemical properties

Vapour pressure

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Reference
Endpoint:
vapour pressure
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods
Remarks:
Detailed report following a ASTM standard.
Justification for type of information:
see read across rationale in Section 13.2
Reason / purpose:
read-across source
Qualifier:
according to
Guideline:
other: ASTM E1782-03
Deviations:
not specified
Principles of method if other than guideline:
ASTM standard.
GLP compliance:
no
Type of method:
other: Differential Scanning Calorimeter - ASTM E1782-03
Temp.:
20 °C
Vapour pressure:
0 mBar
Remarks on result:
other: Extrapolated data
Temp.:
50 °C
Vapour pressure:
0 mBar
Remarks on result:
other: Extrapolated data
Temp.:
60 °C
Vapour pressure:
0 mBar
Remarks on result:
other: Extrapolated data

Results:

Data obtained are data extrapolated data from temperature range from about 140 -155°C down to 50 -100°C.

Extrapolated data at 20°C

1.2 x 10-6mbars

Extrapolated data at 50°C

1.7 x 10-6mbars

Extrapolated data at 60°C

7 x 10-4mbars (liquid)

Extrapolated data at 80°C

10-2mbars (liquid)

Extrapolated data at 90°C

3 x 10-2mbars

Extrapolated data at 100°C

0.1 mbars

Temperature at which the vapour pressure is 4 mbars

136°C

Temperature at which the vapour pressure is 10 mbars

146°C

Temperature at which the vapour pressure is 15 mbars

151°C

Theoretical calculated boiling point

206°C – In reality decomposes

At 20 mbars decomposition of the substance was observed.

The corresponding equation for extrapolation is :

ln P = 39.181 -15467/T

R2=0.9996

Conclusions:
The vapour pressure of the substance is 1.2 x 10-6 mbars at 20°C.
Executive summary:

A detailed study report on the measurement of vapour pressures according to ASTM E-1782 -03 is available. By extrapolation, the vapour pressure of the substance is found to be 1.2 x 10-6 mbars at 20°C.

Description of key information

Vapour pressure of [1,3-phenylenebis(1-methylethylidene)]bis[tert-butyl] peroxide is estimated to be similar to analogous [1,3(or 1,4)-Phenylenebis(1-methylethylidene)]bis[tert-butyl] peroxide, which was found to be 0.00012 Pa at 20°C (by extrapolation)

Key value for chemical safety assessment

Vapour pressure:
0 Pa
at the temperature of:
20 °C

Additional information

An experimental study compliant with accepted scientific principles shows that the vapour pressure of [1,3-phenylenebis(1-methylethylidene)]bis[tert-butyl] peroxide is 60 Pa at 100°C. We have to be careful with extrapolation of the P, T-curve. The results are only valid for liquid peroxides (up to the melting temperature). In consequence, the vapour pressure of solid peroxide will be lower than the extrapolated value of the liquid.

 

An experimental study compliant with accepted scientific principles, selected as Key Study, shows that the vapour pressure of analogous

[1,3(or 1,4)-Phenylenebis(1-methylethylidene)]bis[tert-butyl]peroxide is 0.00012 Pa at 20°C (extrapolated value).

 

Moreover, an estimation of the vapour pressure

has been performed using the EPISUITE model v4 with the estimated boiling point given by the model. Estimated vapour pressure (using Modified Grain method) is 22 Pa at 100°C and 0.0091 Pa at 25°C with the following input data :

- boiling point : 350.78°C (estimated)

- melting point : 54°C (experimental data of analogous 25155-25-3).

Estimated vapour pressure (using Modified Grain method) is 0.0023 Pa at 25 oC using the default calculated mp of 113.26 oC.

 

For specific applications the substance will be warmed between 55 and 60 °C. The substance decomposes after melting at these temperatures. The main vapour emission at this operating temperature will come from the decomposition products like acetophenone. At a temperature of 90 °C the vapour pressure was not detectable (detection limit 0.1 mbar). The calculated vapour pressure at 60 °C is 0.00011 mbar (0.01 Pa), Report AkzoNobel TE 200600519. The calculation is based on extrapolation of the measured vapor pressure in DSC scans in the temperature range of 101 to 124°C. High heating rate is applied to minimize thermal decomposition.The operational temperature will be < 60 °C and thereforethe vapor pressure will be well below 0.01 Pa.

 

These results (experimental and estimated values) show that and [1,3-phenylenebis(1-methylethylidene)bis[tert-butyl] peroxide and analogous 25155-25-3 have a very low potential of volatility.