N-isopropylacrylamide

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Principles of method if other than guideline:

In the static process, at thermodynamic equilibrium, the vapour pressure established in a closed system is determined at a specified temperature. This method is suitable for one component and multicomponent solids and liquids.

Recommended range:
10 up to 105 Pa.

Apparatus
The apparatus comprises a container for the sample installed in a heater assembly used to regulate the temperature of the sample. The container also includes a magnetic stirrer bar and a thermocouple for measuring the temperature of the sample. The apparatus also includes a pressure transducer to measure the pressure.
The sample is charged to the container which is then closed and the temperature is reduced (if required) sufficiently for degassing. The temperature must be low enough to ensure that the air is sucked out, but (in the case of multiple component system) it must not alter the composition of the material. If required, equilibrium can be established more quickly by stirring. The sample can be super cooled with e.g. liquid nitrogen (taking care to avoid condensation of air or pump fluid) or a mixture of ethanol and dry ice. For low temperature measurements a temperature regulated bath connected to an ultra-cryomat can be used.
The sample container is then installed in the heater assembly, the high-vacuum pump is attached to the containment vessel and vacuum is applied to the sample container via the bypass valve. Suction is applied for several minutes to remove the air. If necessary, the degassing operation must be repeated several times.
The sample is then heated, the vapour pressure increases and the vapour pressure is read off directly on the pressure indicator.

GLP compliance:

not specified

Type of method:

static method

Test material

Test material information

Constituent 1

Reference substance name:

N-isopropylacrylamide

EC Number:

218-638-5

EC Name:

N-isopropylacrylamide

Cas Number:

2210-25-5

Molecular formula:

C6H11NO

IUPAC Name:

N-isopropylacrylamide

Test material form:

solid: flakes

Details on test material:

N-Isopropylacrylamide (NIPAM)
Batch No. 2161004

Specific details on test material used for the study:

Purity: 99.41%

Results and discussion

Vapour pressure

Vapour pressure 1

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

11 hPa

Vapour pressure 2

Key result

Test no.:

#2

Temp.:

50 °C

Vapour pressure:

36 hPa

Vapour pressure 3

Key result

Test no.:

#3

Temp.:

75 °C

Vapour pressure:

41 hPa

Vapour pressure 4

Key result

Test no.:

#4

Temp.:

100 °C

Vapour pressure:

512 hPa

Vapour pressure 5

Key result

Test no.:

#5

Temp.:

125 °C

Vapour pressure:

559 hPa

Remarks on result:

other: Potentially polymerising

Any other information on results incl. tables

Experimental results

Temperature, °C	Vapour Pressure, hPa
25	11
50	36
75	41
100	512
125	559*

*potentially polymerising

Applicant's summary and conclusion

Conclusions:

The vapour pressure of NIPAM was found to be:
Temperature, °C Vapour Pressure, hPa
25 11
50 36
75 41
100 512
125 559

Executive summary:

The vapour pressure of a substance is defined as the saturation pressure above a solid or liquid substance. At the thermodynamic equilibrium, the vapour pressure of a pure substance is a function of temperature only.

There is no single measurement procedure applicable to the entire range of vapour pressures. Therefore, several methods are recommended to be used for the measurement of vapour pressure from < 10^-4 to 10⁵ Pa.

Impurities will usually affect the vapour pressure, and to an extent which depends greatly upon the kind of impurity.

For determining the vapour pressure, several methods can be applied in different vapour pressure ranges. For each method, the vapour pressure is determined at various temperatures. In a limited temperature range, the logarithm of the vapour pressure of a pure substance is a linear function of the inverse of the temperature.