Transitions and phases of polytetrafluoroethylene (teflon)

Abstract

Transitions in polybetrafluoroethylene (T ~ ~o n) have been studied as a !U1:ctio~ of pres-sure and temperature. A high-pressure transitlon (5, 000 atm) and ~ lower .pressur e traI:sI-tion were studied . These are believed to result from three polym orphIc fOIIIl:S.. ~he .pres-sure of t he high-pressure transition d ec rea~es ~n.d t ~at of the 10w-pr.essure t ra~sltlOn lllclea~~s wi th increasiilg temperature. A t ri pie powt IS llldlCated at ::"ppI:oxIma~ely 70 C, .and .a t~ u d equilibrium line is found to proceed to higher pressures wIth lllcreasmg temperat':lI.e from this point. Experimental errors in vo lved render tests of all t hermodynamlC condltlons at t he triple point indeterminate.