Poly(styrene‐ r ‐butadiene)‐ b ‐poly(poly(ethylene glycol) methyl ether methacrylate) as a silica dispersant in rubber compounds

To improve the dispersion of silica in silica‐filled styrene–butadiene rubber tire tread compounds, we synthesized poly(styrene‐ r ‐butadiene)‐ b ‐poly(poly(ethylene glycol) methyl ether methacrylate) (p( SB ‐ b ‐ PEGMA )) as a silica dispersant. p( SB ‐ b ‐ PEGMA ) was synthesized by combining living anionic polymerization ( LAP ) and atom transfer radical polymerization ( ATRP ). Initially, α ‐bromoisobutyryl‐terminated poly(styrene‐ r ‐butadiene) ( pSB ‐Br) was prepared by LAP of styrene and butadiene and sequential additions of ethylene oxide and α ‐bromoisobutyryl bromide. pSB ‐Br was then used as the macroinitiator in the ATRP of PEGMA ( M n = 300 g mol −1 ). The structure of p( SB ‐ b ‐ PEGMA ) was characterized using gel permeation chromatography and 1 H NMR spectroscopy. The application of p( SB ‐ b ‐ PEGMA ) as a silica dispersant in styrene–butadiene rubber/silica decreased the optimal vulcanization time and improved the mechanical properties, which included 100% and 300% moduli, crosslinking density and silica dispersion.