Partly epoxidized cis‐ and trans‐1,4‐polyisoprenes and cis‐and trans‐1,4‐polybutadienes were prepared, and their 13C NMR spectra examined. All the prominent resonances in the spectra of the epoxidized polymers were assigned by using lanthanide shift reagent and off‐resonance decoupling experiments. A 13C NMR method of quantitative assessment of the epoxide content was developed following determination of relative spin‐lattice relaxation time (T1) and nuclear Overhauser effect (NOE) parameters of the various carbons in the epoxidized polyisoprenes and polybutadienes.

This article surveys recent advances in the chemical modification of unsaturated polymers, with emphasis on the literature since 1974. Among the topics covered are hydrogenation, halogenation, cyclization, isomerization, epoxidation, cycloaddition, sulfonation, carbenation, and silylation. The olefin functionality is a useful target for modification because of its varied reactivity, and recent work in unsaturated polymer reaction chemistry has yielded significant discoveries and valuable new information. For example, modern synthetic reagents and catalysts (e.g., as phase-transfer catalysts) have been advantageously employed to improve process and/or product quality. Synthetic techniques have been refined to allow the selective modification of specific polymer microstructures or blocks. Moreover, new structural and mechanistic insights have been derived from the judicious use of model compounds and/or specialized characterization methods. The relationship between chemically modified polymer structure and properties is being more clearly defined, and sequence effects are beginning to be appreciated. Finally, important new applications (e.g., elastomers, plastics, motor oil additives) have been discovered for chemically modified diene polymers.

No abstract