The invention belongs to the field of rubber synthesis, and particularly relates to a powdery
styrene-butadiene rubber preparation method, which comprises: (1) sequentially adding water,
styrene-butadiene latex and a
reducing agent aqueous solution into a
polymerization kettle, carrying out stirring heating, adding an
oxidizing agent, and carrying out a cross-linking reaction to obtain surface-cross-linked
styrene-butadiene latex; and (2) adding water and an anti-aging agent to the surface-cross-linked styrene-butadiene latex, then adding a primary agglomeration agent and a secondary agglomeration agent, carrying out agglomeration to obtain a
powder polymer aqueous suspension,
dewatering, washing, screening, and
drying. According to the present invention, the chemical cross-linking is performed on the surface of the styrene-butadiene latex particles, such that the number of the rubber molecules active points on the surface of the particles is reduced, the
plasticity of the surface of the particles is improved, the
viscoelasticity of the surface is reduced, the deformation of the product is reduced, the long-lasting and stable
chemical separation effect is generated between the rubber particles, the consumption of the inorganic separation agent is low, the influence on the performance of the rubber product is low, and the prepared powdery styrene-butadiene rubber has characteristics of uniform particles, good fluidity and good storage stability.