Diene elastomers trans-1,4-Polybutadiene

Commercial samples of l,4-c/5-polybutadiene (SKD E-BR) polybutadiene (Diene 35 NFA BR) 1,4-cw-polyisoprene (Carom IR 2200 E-IR) and polychloroprene (Denka M 40 PCh) were used in the experiments (Table 1). The 1, 4-trans -polyisopiene samples were supplied by Prof. A. A. Popov, Institute of Chemical Physics, Russian Academy of Sciences. All mbbers were purified by threefold precipitation from CCl solutions in excess of methanol. The above mentioned elastomer stmctures were confirmed by means of H-NMR spectroscopy. Ozone was prepared by passing oxygen flow through a 4-9 kV electric discharge. 

When X H, the resulting pol)mier is polybutadiene when XsCHj, it is polyisoprene and when X = C1, it is polychloroprene. The double bond may be cis or trans and would thus give the cis or trans forms of these polymers. It is the 1,4 addition form that predominantly goes into the formation of commercial dienes which are all elastomers. 

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