Influência do agente de clora？？o do catalisador à base de veodímio e da raz？o molar Cl: Nd na polimeriza？？o do butadieno

in this work catalyst systems consisting of diisobutylaluminium hydride (dibah), neodymium versatate (ndv) and a chlorinating agent were employed to study the influence of the chloride source and cl:nd molar ratio on 1,3-butadiene polymerization and polybutadiene's characteristics (molecular weight and microstructure). the chloride sources studied were t-butyl chloride, ethylaluminium sesquichloride (easc) and diethylaluminium chloride (deac). the cl:nd molar ratios used were 1:1, 3:1 e 5:1 for t-butyl chloride; 0.5:1, 1:1 and 3:1 for easc and 1:1, 1.5:1, 3:1 and 5:1 for deac. a maximum value of cl:nd molar ratio exists. moreover, deac showed to be more reactive than easc and t-bucl but t-bucl produced higher molecular weight and cis-1,4 units contents.