Formation of branched polymers in the 2-vinyl pyridine/tributyl dimagnesium iodide/toluene system

Polymerization of 2-vinyl pyridine by tributyl dimagnesium iodide in toluene leads to branched macromolecules. This effect being due to the interaction of growing chains with pyridine rings of some monomer units of poly(vinyl pyridine) is more pronounced at -60°C as compared with the process at −30°C. The possible causes of this difference are discussed