Di-tert-butyl 1,1,4,4-tetramethylbut-2-yn-1,4-ylene diperoxide

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

no guideline followed

Principles of method if other than guideline:

Measurement of vapour pressure with DSC (Differential Scanning Calorimetry) method.

GLP compliance:

not specified

Type of method:

other: differential scanning calorimetry (DSC)

Key result

Temp.:

20 °C

Vapour pressure:

0.011 Pa

Remarks on result:

other: The relationship between the pressure and the temperature was fitted with the Antoine model.

The product was measured at different pressures. The onset temperatures of boiling are given in the table. Further, the recalculated pressure is given for the Antoine fit.

 

Table 1: Vacuum DSC results of the test item

Measured		Antoine fit
P ressure (mbar)	T boiling point (°C)	Calculated pressure after fit (mbar)
0.50	56.0	56.1
0.90	62.5	62.3
2.50	76.1	76.4
3.50	82.1	82.3
5.00	88.3	89.6

 

 

Table 2: Antoine fit parameters for the test item

product	Constant A	Constant B	Constant C	Temperature range (°C)
Trigonox 145 E-85	2.6497	192.47	-264.06	56 - 88

 

 

Antoine:

¹⁰log(p) = A - B/(C + T)

or

P = 10^{[A-B((C + T)]}

T = B/(A –¹⁰log p) -C

 

where: A, B, C: constants

p: pressure (mbar)

T: temperature (K)

 

Table 3: Pressure table of the test item

Temperature (°C)	Pressure (mbar)
45	0.12 extrapolated
50	0.25 extrapolated
55	0.44 extrapolated
60	0.73
65	1.13
70	1.65
75	2.30
80	3.09
85	4.02
90	5.10 extrapolated

Conclusions:

At a temperature of 20 °C a vapour pressure of 0.010855 Pa was calculated for the test item.

Executive summary:

The vapour pressure of the test item was measured at various temperatures with vacuum Differential Scanning Calorimetry (DSC). The vapour pressure of the test substance was measured in the temperature range of 56 - 88 °C. The relationship between the pressure and the temperature was fitted with the Antoine model. In the measured temperature range a vapour pressures between 56.1 and 89.6 mbar were calculated. The vapour pressure at 20 °C was calculated to be 0.010855 Pa.

Description of key information

At a temperature of 20 °C a vapour pressure of 0.010855 Pa was calculated for the test substance.

Key value for chemical safety assessment

Vapour pressure:

0.011 Pa

at the temperature of:

20 °C

Additional information

The vapour pressure of the test item was measured at various temperatures with vacuum Differential Scanning Calorimetry (DSC). The vapour pressure of the test substance was measured in the temperature range of 56 - 88 °C. The relationship between the pressure and the temperature was fitted with the Antoine model. In the measured temperature range a vapour pressure between 56.1 and 89.6 mbar were calculated. The vapour pressure at 20 °C was calculated to be 0.010855 Pa.