Calorimetric properties of polytetrafluoroethylene (teflon) from 0-degrees to 365-degrees-K

Abstract

The tl:erma.l properties of polytetra~~oro e thyl ene (Teflon ) . samples were investigated, uStng an ad l abatJc~vacuum calonmeter. Ihe effect of the annealll1g and quenchtng processes on the heat capacity of a mold ed T eflon sample was studied. The heat-capacity data were used to compute the heat capacity, enthalpy, and entropy of the polymer samples at 5-deg intervals from 0 0 to 365 0 K. The heat-capacity results \\'it h the molded, annealed, and que nched samples of Teflon show the possibility of a glass transformation at about 160 0 K. The lack of a more definite glass-transformation er-fect is attributed to inter-and intramolecular hindrances to configurational changes in the Tefion polymer. The existence of fil'storder transitions at 293 0 and 303 0 K , previously reported by Quinn , Roberts, and \Vork, ,yas confirmed.