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Molar Mass Control by Diethyl Zinc in the Polymerization of Butadiene Initiated by the Ternary Catalyst System Neodymium Versatate/Diisobutylaluminum Hydride/Ethylaluminum Sesquichloride

2006; Taylor & Francis; Volume: 43; Issue: 1 Linguagem: Inglês

10.1080/10601320500405786

1520-5738

Lars Friebe, Julia Maria Müller, Oskar Nuyken, Werner Obrecht,

biodegradable polymer synthesis and properties

The polymerization of 1,3‐butadiene (BD) catalyzed by the ternary Ziegler/Natta catalyst system neodymium versatate (NdV)/diisobutylaluminum hydride (DIBAH)/ethylaluminum sesquichloride (EASC) is investigated in regard to molar mass control by diethyl zinc (ZnEt2). Within the investigated range of ratios of ZnEt2 to NdV, the features of a living polymerization with a reversible exchange of the living polybutadienyl chains between neodymium and zinc are observed. In summary, ZnEt2 can be considered as an efficient molar mass control agent, which has a negligible impact on polymerization rates. In addition to the reduction of molar masses, ZnEt2 also reduces the polydispersity (PDI) and leads to a decrease of the cis‐1,4‐content.