Permanganate Oxidation of Polybutadiene Rubbers

In view of the failure to obtain quantitative yields of the expected carboxylic acids by permanganate oxidation of the several butadiene polymers studied, definite conclusions about their structures cannot be made. The results have a qualitative significance, however, in that the −10° emulsion polymer was found to produce a larger amount of succinic acid than the 50° emulsion polymer and less tricarballylic acid, and thus they correlate with general thinking that lowered temperature of polymerization results in a polymer of more regular structure and less branching. The Alfin polymer, although prepared in a system entirely different from the emulsion system, gave results which indicated a microstructure similar to that of 50° emulsion polybutadiene. Sodium polybutadiene was less completely characterized than the others, but the large amounts of carbon dioxide and β-carboxyadipic acid isolated correlated well with the high percentage of external double bonds known to be present from other methods of analysis.