2,2'-[(4-methylphenyl)imino]bisethanol

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Apr - 02 May 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Type of method:

ring method

Surface tension:

62.5 mN/m

Temp.:

20 °C

Conc.:

1 g/L

Study results
List of measurement results
The measurement results have to be corrected due to the influence of the instrument. The correction factor can be calculated from the ratio of the theoretical value of the surface tension (72.75 mN/m at 20 °C) for water and the measured value for water (Table 1). In this case the correction factor for the instrument is 1.0107.

Water calibration: Temp. = 22 °C, ρ = 0.998 g/cm^3

Table 1

Surface tension of purified water
Value 1	72.0 mN/m
Value 2	72.0 mN/m
Value 3	72.0 mN/m
Value 4	72.0 mN/m
Value 5	71.9 mN/m
Value 6	72.0 mN/m
Arithmetic mean	71.98 mN/m
Standard deviation	< 0.1 mN/m

 

Temperature differences were considered by entry of the density. For the measurements a density of 0.998 g/cm^3 was used.

The first solution was not considered by the evaluation because of slightly higher concentration than 1.0 g/L.

Second test solution: (c = 1.012 g/L), temp. = 20. 4 °C, ρ = 0.988 g/cm^3 age of the solution = 619 min

Table 2

Surface tension of solution
Value 1	61.1 mN/m
Value 2	61.1 mN/m
Value 3	61.1 mN/m
Value 4	61.1 mN/m
Value 5	61.1 mN/m
Value 6	61.1 mN/m
Arithmetic mean	61.1 mN/m
Standard deviation	< 0.1 mN/m

 

Third test solution: (c = 1.011 g/L), temp. = 20. 4 °C, ρ = 0.988 g/cm^3 age of the solution = 240 min

Table 3

Surface tension of solution
Value 1	61.1 mN/m
Value 2	61.1 mN/m
Value 3	61.1 mN/m
Value 4	61.1 mN/m
Value 5	61.1 mN/m
Value 6	61.1 mN/m
Arithmetic mean	61.1 mN/m
Standard deviation	0.1 mN/m

 

Fourth test solution: (c = 1.102 g/L), temp. = 19.8 °C, ρ = 0.988 g/cm^3 age of the solution = 148 min

Table 4

Surface tension of solution
Value 1	63.4 mN/m
Value 2	63.4 mN/m
Value 3	63.4 mN/m
Value 4	63.4 mN/m
Value 5	63.4 mN/m
Value 6	63.4 mN/m
Arithmetic mean	63.4 mN/m
Standard deviation	< 0.1 mN/m

 

Calculation
Surface tension (arithmetic mean of three test solutions): 61.8 mN/m±1.4 mN/m

Surface tension (arithmetic mean corrected by calibration factor determined via water calibration): 62.5 m/Nm

Discussion and Conclusion
The test item N,N-dihydroxyethyl-p-toluidine has a surface tension of 62.5 mN/m (solution with c = approx. 1 g/L).

Description of key information

62.5 mN/m at 20 °C and 1 g/L (ring method, EU Method A.5)

Key value for chemical safety assessment

Surface tension:

62.5

in mN/m at 20°C and concentration in mg/L:

1 000