polyethylene glycol MW 20,000

wt%		log P (dynes/cm^2)

1.5		4.59
2.9		4.98
3.6		5.15
4.7		5.34
5.8		5.55
6.3		5.63
7.1		5.76
9.0		5.89
12.1		6.08
13.1		6.18
14.2		6.29
16.0		6.47
18.3		6.70
18.8		6.68
20.8		6.77
21.6		6.83
22.2		6.83
22.8		6.94
19.0		6.68
22.1		6.83
23.7		6.93
25.0		6.94
26.2		7.03
28.8		7.11
32.7		7.26
34.8		7.34
35.6		7.32
38.0		7.45
39.5		7.48
41.7		7.54
43.2		7.59
45.5		7.67
47.5		7.73

An equation that fits this data is the following.

log P = a + b * (wt%) ^ c

where a = 1.57, b = 2.75 and c = 0.21

Note that it should be applied only over the range of pressures measured.

polyethylene glycol MW 20,000
	At a Temperature of 7-8 degrees C

wt%		log P (dynes/cm^2)

15.3		6.56
17.8		6.75
18.3		6.79
19.5		6.82
20.8		6.91
21.3		6.92
22.9		6.99
23.2		7.00
24.3		7.04