Resumo

PIRES, Neusa M. T.; COSTA, Marcos A. S.  e  COUTINHO, Fernanda M. B.. 1,4 cis-Polymerization of butadiene by the catalyst system titanium tetrachloride/triisobutylaluminium/iodine. Polímeros [online]. 2000, vol.10, n.4, pp.230-237. ISSN 1678-5169.  http://dx.doi.org/10.1590/S0104-14282000000400011.

A modified Ziegler-Natta type catalytic system consisting of TiCl₄/I₂/Al(i-Bu)₃ was used to produce polybutadiene with high content of 1,4-cis repeating units. The influence of the catalytic system composition and temperature on the catalyst activity, molecular weight and microstructure of the polybutadiene was studied. The polymers were characterized by infrared spectroscopy and size exclusion chromatography. Polybutadiene with up to 92% of 1,4-cis repeating units and low gel content was produced. The polymer molecular weight was dependent on the catalytic system composition and reaction temperature. The weight-average molecular weight varied from 3 to 50 x 10⁴; the molecular weight distribution was low, ranging, from 1.8 to 3.3. The maximum catalytic activity was achieved at molar ratios Al/Ti = 5 and I₂/Ti = 2.

Palavras-chave : Ziegler-Natta catalyst; titatium tetrachloride; butadiene; 1,4-cis polybutadiene.

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