tert-butyl peroxypivalate

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1997-10-16

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

other: ASTM E1782

Deviations:

not specified

Principles of method if other than guideline:

Measurement of vapour pressure with DSC ( Differential Scanning Calorimetry)

GLP compliance:

not specified

Type of method:

other: differential scanning calorimetry (DSC)

Temp.:

37.9 °C

Vapour pressure:

4.02 mBar

Remarks on result:

other: measured result, not calculated by Antoine fit or Clausius Clapeyron

Temp.:

41.1 °C

Vapour pressure:

5.01 mBar

Remarks on result:

other: measured result, not calculated by Antoine fit or Clausius Clapeyron

Temp.:

46.9 °C

Vapour pressure:

7.03 mBar

Remarks on result:

other: measured result, not calculated by Antoine fit or Clausius Clapeyron

Temp.:

51 °C

Vapour pressure:

8.53 mBar

Remarks on result:

other: measured result, not calculated by Antoine fit or Clausius Clapeyron

Temp.:

53.1 °C

Vapour pressure:

10.01 mBar

Remarks on result:

other: measured result, not calculated by Antoine fit or Clausius Clapeyron

- The test substance vapour pressure was measured in the temperature range of 38 °C up to 53 °C. Extrapolation was carried out, showing that error increases drastically with too far extrapolation.

- The measurements were performed at tempertaures that are far above the SADT of the tets substance. Handeling the test substance at these temperatures while doing the DSC test was possible because very low amounts were used and the measurements were very fast.

Conclusions:

At temperatures between 38 °C to 53 °C vapour pressure between 4.02 to 10.01 mBar were measured for tert-butyl peroxypivalate (TBPPI).

Executive summary:

The vapour pressure of TBPPI, was measured at various temperatures with vaccum DSC. The temperature range of the method is limited. The lower pressure limit depends on the capacity of the vacuum pump (about 0.5 mbar), the lower temperature limit of the DSC-apparatus (25 °C) or by the melting point of the product. The upper limit depends on the thermal stability of the product. In the case Trigonox 25-C75 the lower pressure is limited by the pump capacity. The vapour pressure of TBPPI in the temperature range of 38 °C to 53 °C was measured although the temperatures were above the SADT. That was feasible in this DSC test as the amounts used were low and the measurements were very fast. At temperatures between 38 °C to 53 °C vapour pressure between 4.02 to 10.01 mBar was measured for tert-butyl peroxypivalate (TBPPI). Extrapolation of the obtained results showed that the error in the pressure will increase at extrapolation.

Description of key information

At temperatures between 38 °C to 53 °C vapour pressure between 402 to 1001 Pa were measured for tert-butyl peroxypivalate (TBPPI).

Key value for chemical safety assessment

Vapour pressure:

119 Pa

at the temperature of:

20 °C

Additional information

The vapour pressure of tert-butyl peroxypivalate (TBPPI), 95 % purity, was measured at various temperatures with vacuum DSC. The vapour pressure of the test substance in the temperature range of 38 °C to 53 °C was measured although the temperatures were above the SADT. That was feasible in this DSC test as the amounts used were low and the measurements were very fast. At temperatures between 38 °C to 53 °C, vapour pressure between 4.02 to 10.01 mBar was measured for TBPPI. Extrapolation of the obtained results showed that the error in the pressure will increase at extrapolation.

Vapoure pressure was calculated to be 169 Pa and 119 Pa at 25 °C and 20 °C, respectively.