Skeist critical surface tension table

Now let's talk about — this comes out of the second edition of Skeist. He's got a bunch of hydrocarbon compounds, from polyvinyl chloride: a carbon backbone, two chlorines and two hydrogens in the chain. He lists the coefficient of friction. Remember I told you friction or lubrication is the opposite of joining. He's looking at coefficient of friction. The guy who wrote this chapter was at the Naval Research Lab — a good chemist. He was looking at the bonding, critical surface tension in dynes per centimeter, which is ergs per square centimeter, which is 0.001 joules per square meter. Polyvinyl chloride: 40. One chlorine rather than two drops to 39. Polyethylene — there's my pipe — 31, all hydrogens. Put a fluorine in there, polyvinyl fluoride: 28. Two fluorines: 25. Polytrifluoroethylene, three fluorines: 22. Four fluorines, Teflon: drops to 18. Teflon has the lowest surface tension of virtually any solid. We'll talk about water on ice and things on Monday.