Correlation between tacticity and thermal stability in comparison with other defect structures in PVC

摘要: Abstract Fractions from six PVC samples, which have been extensively studied in respect of defect structures content by the IUPAC Working Party on Defects and Stability, were obtained extracting with acetone. The whole polymers, as well their acetone soluble insoluble fractions, characterized determining osmotic molecular weight tacticity. Then they thermally degraded up to conversion 0.3% powder state at 180°. polyene distribution polymers was u.v.-vis spectroscopy. weights fractions lower isotactic contents higher than those both fraction polymer. variation degradation rate material overall appears be linear, suggesting that influences are closely related. On other hand, two samples deviate linear behaviour, probably because a result severe polymerization conditions used for these samples. spectra equally show very different distribution, exhibiting an enhanced concentration polyenes 7–9 double bonds (λ between 393 437 nm). behave much same way tacticities, earlier, so above results confirm influence some conformations degradation.