Further studies on the pyrolysis of polytetrafluoroethylene in the presence of various gases

Abstract

Th e t h er mal decomposit ion of polytetrafluoroeth ylene in t he presence o f gases or vapors h as bee n exp lored in t he range 450 0 to 500 0 C. Gases th a t have been used ca n be di vid ed into t hree groups, d ep ending on whether t hey inhibit, catalyze, or e xert no effect on the t herma l-deco mpos it ion process. Fluorin e-containing gases, i. c., ClF3 and IFs, which are capa ble of dissocia t ing at t he py rolys is te mperatures to give fluori ne atoms, showed t he most m ar ked inhibi t io n ye t obser ved. From the brevity of t he dura tio n of inhibi t ion , i t is concluded t hat t he fluorine a toms directly atta ck t he pol y mer to produ ce sc iss io ns t hrough a metathetica] r eaction.

Pyrolysis of fluorocarbon polymers

“…There is ample evidence that linear perfluoroaliphatic substances have a high thermal stability [ 1 , 2 ] 1 but few if any results are available for branched and aromatic perfluorocompounds or for the various copolymers containing fluorine, which are becoming important commercially. The mechanism of depolymerization or decomposition of these materials, with the possible exception of polytetrafluoroethylene [ 3 to 7 ], is also in need of extensive investigation, since such information would be useful in understanding the problems involved in the development of thermally more stable materials. There are numerous possible polymeric structures not yet synthesized.…”

Generation of perfluoroisobutylene reference sample and determination by gas chromatography with electron capture and flame ionization detection

“…They also report that at 725 °C, PFIB pyrolyzes to form perfluoromethane. The catalytic effect of oxygen (and other gases) on the pyrolysis of PTFE was noted by Michaelson et alr (9). More recently, PTFE and polyfluoroethylenepropylene (PFEP) were pyro-0003-2700/82/0354-2607$01.25/0 55144 lyzed in both nitrogen and air under both dry and humid conditions in a flowing system by Arito et al (10).…”