You are targeting a high cis-1,4 polybutadiene, known for its excellent elasticity and low heat buildup, but your characterization (via NMR or FTIR) reveals a lower-than-expected cis content and a high proportion of trans units. The use of alkylcalcium ([8]-[15]), strontium [15] and barium ([15]-[17]) derivatives are reported to produce polybutadiene with a low vinyl content (10 – 25%) and a 1,4-cis / 1,4-trans ratio ranging from 0.16 to 7 in apolar media. Butadiene may be present in polymer macromolecules in the form of cis-1,4, trans-1,4 and 1,2 structural units with pendant vi-nyl groups. Cobalt Diethyldithiocarbamate + Ethylaluminumsesquichloride used as a catalyst for the synthesis of hyperbranched, low solution viscosity, high molecular weight 1,4-cis-polybutadiene containing 20–40% of 1,2-vinyl bonds. Hydrogenation of polybutadiene converts both cis and trans isomers to the same linear structure and vinyl groups to ethyl branches. A polybutadiene sample of molecular weight 168,000 was found by infrared spectroscopy to contain double bonds consisting of 47.2% cis, 44.9% trans, and 7.9% vinyl. Comprehensive analysis of polybutadiene rubber covering molecular structure, synthesis processes, and applications in high-performance elastomeric systems for tire and automotive industries. Low vinyl polybutadiene rubber achieves superior low-temperature flexibility and processability through controlled microstructure. Explore molecular engineering, catalyst systems, and industrial applications. The ability of 1,3-butadiene to polymerize into different isomeric structures—cis-1,4, trans-1,4, and vinyl-1,2—gives rise to a family of polymers with a wide range of properties, from highly elastic rubbers to rigid plastics. A ligand-free Ni (acac)2/EASC Ziegler–Natta catalytic system was developed for the efficient synthesis of low molecular weight liquid polybutadiene (LPB) featuring high 1,4 content. In terms of the connectivity of the polymer chain, butadiene can polymerize in three different ways, called cis, trans and vinyl. The cis and trans forms arise by connecting the butadiene molecules end-to-end, so-called 1,4-polymerisation.