Structural analysis of regular copolymers of Butadiene and methylene with repeat unit [But-(CH 2) n-But] by the use of model compounds—III. An analysis of the factors which influence the ratio of cis and trans 1,4 addition

Abstract

In previous papers the 1,2 to total 1,4 ratios in copolymers of butadiene of repeat unit-[But-But-R] 1, where R is an alkyl ligand, have been determined by preparing model compounds HR-But-But-RH under identical conditions. Use of capillary column GLC enables the cis and trans isomers to be separated and the effect of varying experimental parameters on the cis/trans ratio is examined. This ratio is shown to be more sensitive to reaction temperature than the 1,2 to total 1,4 ratios previously studied. Results indicate that when R = (CH 2) n the cis/trans ratio is independent of n for values of n > 1.