Raman investigation of the structure of lower isobutene polymers

Abstract

1. The available results of chemical and Raman spectrum investigations on the structure of isobutene polymers (trimers and tetramers) were found to be highly contradictory. In the present investigation chemical and Raman spectrum results are in agreement and indicate the predominance of the isomers (H), (V), (VI), and (XIV) in the appropriate fractions; from the trimer fraction onward these are inactive in further polymerization; the active forms [ (VII), (IX), (X), etc] participate in the formation of higher polymers and do not accumulate in appreciable amount at the lower stages of polymerization. 2. The view that the doublet in the double-bond region of frequencies for lower polymers is the result of Fermi resonance and rotation isomerism is shown to be unsound. The doublet of frequencies arises from the presence of a mixture of isomers having different double-bond frequencies.