• BR is a synthetic rubber with regular structure formed by polymerization of butadiene. According to the different catalysts, BR can be divided into nickel, cobalt, titanium and rare earth butadiene rubber.
• In the early 1930s, Germany and the former Soviet Union began to produce butadiene rubber with metal sodium as a catalyst, known as sodium butadiene rubber. But its structure regularity is poor, physical properties and processing performance is not good, can not be called butadiene rubber. 
• In the 1950s, the practice of ZieglerNatta coordination oriented polymerization theory promoted the rapid development of butadiene rubber synthesis technology. In 1956, the United States with Alr3TiBr4 catalytic system synthesis of butadiene rubber. Subsequently, cobalt, nickel and rare earth catalyst phases continued to develop, and the production capacity of butadiene rubber was second only to styrene butadiene rubber, ranking the second place among the synthetic rubber. In 2013, according to the World Association of Synthetic Rubber Producers, the production capacity of butadiene rubber (mainly BR) was 4.718 million tons/year【7】.
• Rare earth butadiene rubber is regarded as the upgrade of nickel butadiene rubber due to its excellent performance and is gradually paid attention to by the industry. Compared with nickel-based SBR, rare earth SBR has higher elasticity, better tensile properties, lower heat generation and rolling resistance as well as excellent wear resistance and fatigue resistance and other physical and mechanical properties.

• BR meets the development needs of high speed, energy saving, safety, environmental protection and other aspects of high performance tires, and is often used in high performance green tires. The superior trend of the development of the high performance green tires can be seen from figure 3 and 4.【8】
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                                 Figure 3.Market projection of high performance tire

                                        Figure 4.Market share in 2018

• Besides, the potential future development direction of BR is semiconductor. There are scientific studies that show that cis-1,4-polybutadiene can be converted into a semiconductor when doped with iodine. The conductivity achieved by iodine doping was about 10−6 S/cm. The products were characterized by elemental analysis, FT-IR, differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) techniques.
• Temperature dependence of electrical conductivity exhibits a semiconductor behavior. 【9】The figure 5 illustrates the conductivity change, which shows the role of the methyl group in enhancing the conductivity by increasing the electron density in the double bonds.

                                                          Figure 5.