CIS-TRANS isomerisation of polyacetylene analysed by DSC

Summary form only given. Different samples of conventionnal Polyacetylene PA have been prepared and compared by DSC analysis (horizontal as well as verticaly as free standing films on the quiet interface of the catalyst solution-acetylene). Calorimetric study of non doped polyacetylene films allowed us to determine kinetic parameters of the cis-trans isomerisation i.e. A = (2.27 /spl plusmn/ 2.45) 10/sup 13/ / s and E = 31 kcal/mol. Our results confirm that the exothermal peak observed at 145/spl deg/C represents essentially the isomerisation of a film containe PAcis to PAtrans. On the other hand lower is the %Trans, higher will be the enthalpy (cal / g of film) with a /spl Delta/Hmax = - 51.7 cal / g for Pacis and with /spl Delta/ = 0 for 2.8% PAcis film.