ABSTRACT
Starkweather 1 studied the sorption by commercial PTFE film (estimated degree of crystallinity, 41% of liquids with i δ between 12.5 and 23.5 MPa1/2, a Gee plot intercept giving a Hildebrand parameter of 12.7 MPa1/2. A graph is included in Handbook of Solubility Parameters and Other Cohesion Parameters. 2 This value was reported by Gaylord, 3 van Krevelen and Hoftyzer, 4 and Small, 5 with group molar attraction constants which subsequently have been used widely, calculated 12.7 MPa1/2, also. The group contribution method of van Krevelen and Hoftyzer 4 , 6 yielded 11.7 MPa1/2, and Lawson and Ingham 7 estimated a Hildebrand parameter of 13.3 MPa1/2 from refractive index data.
