Neodymium Ziegler–Natta catalysts: Evaluation of catalyst ageing effect on 1,3-butadiene polymerization

Catalysts constituted by neodymium versatate, diisobutylaluminium hydride and t-butyl chloride were used in this work. After their synthesis, they were aged at 40 °C for 48 h. Afterwards, they were maintained at 10 °C for more 5, 15, 40, 80, 160 and 250 days and finally the aged catalysts were evaluated in butadiene polymerization. The polybutadienes were characterized by size exclusion chromatography (SEC) to determine the molecular weight characteristics and by infrared spectroscopy (FTIR) to determine the microstructure. The aim of this work is to evaluate the effect of ageing time on 1,4 polymerization of butadiene. The results showed that the stereoselectivity of the active sites was not affected by the ageing conditions. However, the catalyst activity increased for long times of ageing.