Isopropyl trifluoroacetate

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Final report: April 21st, 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

no

Type of method:

static method

Test material

Test material information

Constituent 1

Reference substance name:

Isopropyl trifluoroacetate

EC Number:

206-922-1

EC Name:

Isopropyl trifluoroacetate

Cas Number:

400-38-4

Molecular formula:

C5H7F3O2

IUPAC Name:

propan-2-yl 2,2,2-trifluoroacetate

Test material form:

liquid

Details on test material:

Name: Isopropyl trifluoroacetate

Specific details on test material used for the study:

PRINCIPLE
The static method is used to evaluate the vapour pressure of chemical compounds. In this process, at thermodynamic equilibrium, the vapour pressure established in a closed system is determined at a specified temperature. This method is suitable for pure solids and/or liquids as well as mixtures thereof. It provides accurate results for pressures ranging from 10 up to 105 Pa, but can also be used in the range 1 to 10 Pa. In this case, providing care is taken.

EQUIPMENT
Measurement cell: A custom-made static cell mounted
Temperature probe: Pt100 type
Pressure sensor: MKS 631, 0-1000 torr absolute
Data acquisition unit: Agilent 34970-A

PERFORMANCE OF THE TEST
About 15 mL of the test item was introduced into the apparatus and degassed at 5°C. The test item was then transferred into the static cell, which was previously put under vacuum. The measurement cell is surrounded by a jacket through which a thermally regulated fluid can circulate.
The temperature of the bath was adjusted to different values from 6.6 °C up to 40.2 °C. For each bath temperature, once the temperature and pressure inside the cell were stable, three readings were made, spaced by not less than 5 minutes.

Results and discussion

Vapour pressure

Vapour pressure 1

Key result

Temp.:

20 °C

Vapour pressure:

12 192 Pa

Vapour pressure 2

Key result

Temp.:

25 °C

Vapour pressure:

15 654 Pa

Any other information on results incl. tables

The measured data is self-consistent, as shown by the coefficient of determination: R²=0.999.

Definition of terms: T_exp= Experimental temperature (°C)

                              P_exp= Experimental pressure (mbar)

Table 1: Data recorded during the experiment

Texp [°C]	Pexp [mbar]	1/Texp [K-1]	Ln(Pexp) with Pexpin mbar
20.45	125.95	0.00341	4.836
20.53	126.14	0.00341	4.837
20.54	126.17	0.00340	4.838
6.55	58.65	0.00358	4.072
6.56	58.65	0.00358	4.072
6.57	58.65	0.00358	4.072
11.69	77.59	0.00351	4.351
11.67	77.56	0.00351	4.351
11.67	77.52	0.00351	4.351
30.70	205.11	0.00329	5.324
30.67	205.09	0.00329	5.323
30.69	205.03	0.00329	5.323
40.19	313.57	0.00319	5.748
40.18	313.56	0.00319	5.748
40.14	313.47	0.00319	5.748

The uncertainty of measurement for pressure was about 0.7 mbar and for temperature, it was about 0.05 °C The measured vapour pressures were used to regress the coefficients of Antoine's law reported in Table 2 using the following equation. They enable to calculate the vapour pressure of the test item at any given temperature provided this temperature falls within the range specified in the same table.

Ln P = A + B / (T+C)

With P_calc(calculated pressure) in mbar and T in K

Table 2: Antoine's law coefficients

A	B	C
16.08363	-2489.57495	-72.44769

The maximum error involved by the modelling of vapour pressure with our Antoine’s law is about 0.8 mbar which is in magnitude of the uncertainty of measurement of pressure.

Table 3: Average of measured values and calculated data with Antoine's law coefficients

Texp [°C]	Pexp [mbar]	Pcalc [mbar]	Pexp– Pcalc [mbar]
20.51	126.09	125.12	0.97
6.56	58.65	58.67	0.02
11.68	77.56	78.37	0.81
30.69	205.08	205.29	0.21
40.17	313.53	313.55	0.02

Applicant's summary and conclusion

Conclusions:

Using the Antoine’s law, the vapour pressure was calculated at 20 and 25°C.
The vapour pressure of the test item at 20°C is 121.92 mbar +/- 0.97 mbar.
The vapour pressure of the test item at 25°C is 156.54 mbar +/- 0.97 mbar.

Executive summary:

The vapour pressure of Isopropyl trifluoroacetate was determined using a static cell, following OECD guideline 104.

The vapour pressure of the test item at 20°C is 121.92 mbar +/- 0.97 mbar.

The vapour pressure of the test item at 25°C is 156.54 mbar +/- 0.97 mbar.