Diene polymers having reduced hysteresis and improved raw viscosity incorporating primary partial coupling and terminals formed from fused-ring polynuclear aromatic compounds or aromatic nitrile compounds.

摘要

Diene polymers or copolymers having improved raw polymer viscosity and reduced hysteresis in the cured and carbon black reinforced state are provided. These diene polymers or copolymers comprise a mixture of diene polymer or copolymer chains containing carbon-tin bonds in the main polymer or copolymer chains and diene polymer or copolymer chains containing terminals derived from aromatic nitrile coumpounds. The diene polymer or copolymers are prepared by first coupling a portion of the living diene polymer or copolymer chains obtained by anionic polymerization using a tin polyhalide coupling agent and then terminating the remaining living diene polymer or copolymer chains using aromatic nitrile compounds. The resultant diene polymers or copolymers have improved raw polymer viscosity and when compounded with carbon black and cured have reduced hysteresis properties. The polymers can be utilized to form elastomer compositions for tire treads having reduced rolling resistance.