Kinetics of trifluorovinyl ether cyclopolymerization via Raman spectroscopy

Abstract

Polymerization kinetics of tris(trifluorovinyloxyphenyl)ethane (TVE) in the bulk are characterized by measuring the disappearance of the fluoro-olefin Raman signal at 1831cm-1 normalized to an aromatic ring signal as an internal standard. The nth order kinetic model (dx/dt = k(1 − x)n) was applied to determine a reaction order of 2·0. Reaction rates below 85% conversion measured for various temperatures ranged from 2·2×10-3min-1 (t1/2 = 454 min) to 3·1×10-1min-1 (t1/2 = 3·3 min) for 130°C and 210°C, respectively. Above 85% olefin conversion, second order rate constants deviated from linearity as gelation ensued. An Arrhenius activation energy of 24·6 kcalmol-1 was determined. The non-destructive Raman technique was found to be an excellent method for measuring the cure kinetics in the bulk and may be applicable to ‘on-line’ needs for general application of perfluorocyclobutane (PFCB) polyarylether materials. © 1998 SCI.