Star high styrene rubber and preparation method thereof

The invention provides star high styrene rubber and a preparation method thereof, and the star high styrene rubber has a structural formula as follows: Y-[B1->S1-B2/S2]4, wherein Y is Si or Sn; B1->S1 is polystyrene or polybutadiene tapered block copolymer; B2/S2 is polystyrene or polybutadiene random copolymer; in the structural formula, the polystyrene or polybutadiene tapered block is 40-75wt%, and the mass fraction of the polystyrene or polybutadiene random copolymer is 25-60wt%; and in the star high styrene rubber copolymer, the styrene content is 45-75wt% and the butadiene content is 25-55wt%.The preparation method of the star high styrene rubber is as follows: adding an initiator once, adding monomers in a polymerization system at twice in a sequence, and then adding a coupler for coupling reaction after the polymerization to obtain the star high styrene rubber. The high styrene rubber in the invention has the characteristics of high hardness and good strength, can improve properties of rigidity, hardness and wearing resistance and lower contraction rate of the rubber products when being used with various synthesized rubber or natural rubber together, and can be widely usedin shoemaking industry, tyre industry, printing industry and other industries.