High temperature pyrolysis of poly(phenylene vinylene)swith poly(з-caprolactone) or polystyrene side chains

摘要

High temperature pyrolysis studies of poly(phenylene vinylene)s PPVs with lateral substituentspoly(ε-caprolactone) (PPV—PCL) or poly(ε-caprolactone)and alternating Br (PPV—PCL—Br) or polystyrene(PPV—PSt) clearly showed that thermal stability of both thesubstituent and PPV were affected by the thermal stabilityof the other. In all the polymers under investigation,decomposition started by the degradation of the substituent.The thermal stability of the PPV backbone increased in theorder PPV—PCL—Br < PPV—PCL < PPV—PSt. When thethermal stability of the substituent was significantly lowerthan that of the PPV backbone, as in the case of PPV—PCLand PPV—PCL—Br, then the radicals generated at earlystages of pyrolysis coupled before the temperature reachedto the values necessary for complete decomposition. Thisinturn yielded a thermally more stable crosslinked struc-ture. The increase in thermal stability was greater uponcoupling of the radicals generated on the PPV backbone.