Methacrylamide

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04.01.2005 - 13.01.2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

adopted on 27 July 1995 and EU test method A.4 [Directive 92/69/EEC, Official Journal L 383 A 1992] with the vapour pressure balance

Deviations:

no

Principles of method if other than guideline:

A sample of the test item is heated in a small furnace, placed in an evacuated bell jar. The furnace is
covered by a lid which carries small holes of known diameters, The vapour of the substance,
escaping through one of the holes, is directed onto a balance pan of highly sensitive balance which is
also enclosed in the evacuated bell jar. The momentum of the vapour jet acts as a force on the
balance.

Procedure:
Apparatus:
Vapour pressure balance: Netzsch Typ 433 (Netzsch)
Pressure measurement: Combivac 1T 230 (Leybold)
Vacuum pump: Trivac B, Typ D 25 B (Leybold)
Molecular vacuum pump: Turbovac 450 (Leybold)
Temperature regulation: Netzsch 41 0 (Netzsch)
Parameters:
Degassing: 180 min at 30 °C (vacuum)
Cross-section blende na. 1 : 6.0089 mm² (starting at -10 "C)
Vacuum at initial temperature: 4 * 10 E-7 hPa
Initial temperature: -10 "C
Holding time: 10 min
Heating rate: 1 °C/min
Final temperature: 30 "C

GLP compliance:

yes

Type of method:

effusion method: vapour pressure balance

Specific details on test material used for the study:

Supplier: Evonik Röhm GmbH, Germany
Batch No.0011141123
Purity: 99.4
%
Impurities: 0.46% water
ca. 300 ppm methacrylic acid

Key result

Temp.:

20 °C

Vapour pressure:

0.002 hPa

The sample was degassed under vacuum. The rneasurements started at the initial temperature and the temperature was increased stepwise.

	Temperature [°C]	Inverse temperature x 1000 [K -1]	Vapour pressure (*) [hPa]
	-10	3.800	0.000058
	0	3.661	0.00010
	5	3.595	0.00034
	10	3.532	0.00069
	15	3.470	0.0010
	20	3.411	0.0015
	25	3.354	0.0026
	30	3.299	0.0054
Calculated pressure:	20	3.411	0.0015

(*) Mean value of triplicate measurements

Due to the tendency of the test item to sublimate at higher temperatures the determination of the vapour pressure started below room temperature at -10°C.

The vapour pressure of Methacrylamide at 20°C was interpolated graphically in the log p vs 1/T plot. It corresponds to the measured value at 20 °C of 1.5 * 10E-3 hPa.

Conclusions:

The vapour pressure of Methacrylamide was determined according to OECD guideline no. 104 [adopted an 27 July 1995 and EU test method A.4
[Directive 92/69/EEC, Official Journal L 383 A 1992 with the vapour pressure balance method.
Vapour pressure was 1.5 x 10 E-3 hPa at 20 °C

Executive summary:

The vapour pressure of Methacrylamide was determined according to OECD guideline no. 104 [adopted on 27 July 1995 and EU test method A.4 [Directive 92/69/EEC, Official Journal L 383 A 1992] with the vapour pressure balance method. The vapour pressure was determined to be 1.5 x 10 E-3 hPa at 20 °C

Description of key information

The vapour pressure of Methacrylamide was determined according to OECD guideline no. 104 [adopted on 27 July 1995 and EU test method A.4 [Directive 92/69/EEC, Official Journal L 383 A 1992] with the vapour pressure balance method. The vapour pressure was determined to be 0.0015 hPa at 20 °C

Key value for chemical safety assessment

Vapour pressure:

0.15 Pa

at the temperature of:

20 °C