polyethylene glycol MW 2000

wt%		log P (dynes/cm^2)

5.0		6.20
10.0		6.39
15.0		6.70
20.0		6.91
25.0		7.13
30.0		7.32
35.0		7.49
40.0		7.66	
9.9		6.32
15.0		6.60
20.0		6.95
25.0		7.09
30.0		7.28
34.7		7.40	
5.0		6.04
10.0		6.37
15.0		6.79
20.0		6.94	
10.0		6.38
20.0		6.90
30.0		7.32
40.0		7.66
5.0		6.15
5.0		6.14
15.0		6.66
15.0		6.65
15.0		6.63
15.0		6.68
25.0		7.1
25.0		7.11	
35.0		7.50	
35.0		7.51

An equation that fits this data is the following.

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

where a = 5.60, b = 0.18 and c = 0.67

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