Composition-properties relationships in propene-ethene random copolymers obtained with high-yield Ziegler-Natta supported catalysts

The crystallization and thermal behaviour of crystallizable random propene/ethene copolymers (P-co-E) was systematically investigated. Index of crystallinity and, index of ?-form, enthalpy and entropy of fusion, equilibrium melting temperature, spherulite growth rate, and overall kinetic rate constant were determined and correlated with the overall ethene content and with the concentration of specific chemical defects as determined by 13C NMR analysis (PEP, EPP, EPE triads). The samples of the copolymers, obtained with very-high-yield Ziegler-Natta catalysts, were characterized by IR, 13C NMR, wide angle X-ray scattering, and differential scanning calorimetry.