Acetic acid, 2,2-difluoro-2-[[2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy]-, ammonium salt (1:1)

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-12-03 to 2011-01-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: vapour pressure balance

Specific details on test material used for the study:

Test item name (as identified on the study report): Cyclic C6O4 Ammonium salt
Chemical name: Acetic acid, 2,2,-difluoro-2-[[2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy]-, ammonium salt (1:1)
CAS Np.: 1190931-27-1
Purity: 98.2% (Titration)
Batch No.: Sample 156/17
Molecular Formula: C6H4O6NF9
Molecular weight: 357 g/mol
Physical state: White to light beige powder
Storage conditions: Room temperature (10-30°C)
Expiry date of the test item: December 31, 2020

Key result

Temp.:

ca. 20 °C

Vapour pressure:

ca. 0 hPa

Remarks on result:

other: Calculated according to the Antoine equation.

Key result

Temp.:

ca. 25 °C

Vapour pressure:

ca. 0 hPa

Remarks on result:

other: Calculated according to the Antoine equation.

Temp.:

ca. 50 °C

Vapour pressure:

ca. 0 hPa

Remarks on result:

other: Calculated according to the Antoine equation.

Thermal Stability

The DSC-measurement in a closed glass crucible with the test item showed an endothermic effect in the temperature range of 55 – 80 °C and an broad exothermal effect the temperature range of 90 – 210 °Cwith an energy of 189 J/g.

A graphical presentation of the DSC (glass crucible) is given on figure 1.

Vapour Pressure Balance (Effusion Method)

The vapour pressure was measured in the temperature range of 21.5 °C to 66 °C. Above 34 °C a vapour pressure could be measured.

The measured vapour pressures at the corresponding temperatures are listed in the following table:

Temperature / °C	Vapour pressure / hPa
33.8	7.5× 10^-6
40.4	1.5× 10^-5
44.6	1.9× 10^-5
51.2	1.3× 10^-4
55.8	4.8× 10^-4
59.9	5.8× 10^-4
63.1	9.0× 10^-4
66.3	2.2× 10^-3

The values for 20, 25 and 50 °C are calculated, using the Antoine constants A, B and C as shown there.

Conclusions:

The vapor pressure values calculated through the Antoine equation and based on experimental measurements conducted in the temperature range of 34 °C-66 °C are the following:
0.00000025 hPa at 20 °C
0.00000075 hPa at 25 °C
0.00011 hPa at 50 °C

Executive summary:

The vapour pressure of the test item cC6O4 ammonium salt was determined under GLP according to the EU method A.4 “Vapour Pressure” (2008), to the OECD guideline No. 104, “Vapour Pressure” (2006) and to the OECD guideline No. 113, “Screening test for thermal stability and stability in air” (1981).

The study was conducted according to the vapour pressure balance method (effusion method).

As preliminary investigation the thermal stability of the test item was determined by differential scanning calorimetry (DSC).The DSC-measurement in a closed glass crucible with the test item showed anendothermic effectin the temperature range of 55 – 80 °C and a broad exothermal effect in the temperature range of 90 – 210 °Cwith an energy of 189 J/g.

The apparatus for experimental measurements consists ofa high vacuum chamber. The test item was filled into a furnace in the chamber from which the sample evaporated. The vapour forms a molecular jet of defined geometry limited by an orifice, the vapour jet is condensed on a plate cooled down below – 100 °C. The plate forms one end of an ultra micro balance.

The vapour pressure of the test item is calculated from the increase of mass Dm during an elapsed time period Dt. The vapour pressure was measured in the temperature range of 21.5 °C to 66 °C. Above 34 °C a vapour pressure could be measured.

Vapour pressure values for 20, 25 and 50 °C were calculated through the Antoine equation using the A,B,C constants as reported in the equation.

The calculated values for vapor pressure of the test item cyclic C6O4 ammonium salt are the following:

0.00000025 hPa at 20 °C

0.00000075 hPa at 25 °C

0.00011 hPa at 50 °C

Description of key information

The vapour pressure of the test item cC6O4 ammonium salt was determined under GLP according to the EU method A.4 “Vapour Pressure” (2008), to the OECD guideline No. 104, “Vapour Pressure” (2006) and to the OECD guideline No. 113, “Screening test for thermal stability and stability in air” (1981).
The study was conducted according to the vapour pressure balance method (effusion method).

Key value for chemical safety assessment

Vapour pressure:

0 hPa

at the temperature of:

25 °C

Additional information

Two data of vapour pressure are available.

The vapour pressure value obtained experimentally according to the vapour pressure balance method (effusion method) was selected as key study for this endpoint because of its higher reliability in comparison to the calculated value (< 1.8 x 10 -7 Pa at 25 °C) obtained on the basis of the boiling point of 400 °C and using the Modified Watson Correlation.

The vapor pressure values based on the experimental measurements and calculated through the Antoine equation are the following:

0.00000025 hPa at 20 °C

0.00000075 hPa at 25 °C

0.00011 hPa at 50 °C.