Diene polymers having reduced hysteresis and improved raw viscosity incorporating primary partial coupling and terminals formed from vinyl compounds containing heterocyclic nitrogen groups.

摘要

Diene polymers or copolymers having improved raw polymer viscosity, good processability in carbon black reinforced stocks 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 vinyl-compounds containing heterocyclic nitrogen groups having the structural formula: <CHEM> Wherein R<5> and R<6> are selected from the groups consisting of H, alkyl, alkylaryl, aryl and O,N-containing alkyl, alkylaryl, and aryl groups and wherein X is a radical selected from the group consisting of <CHEM> Wherein R<7>, R<8>, R psi , R6, R7, and R3/4 are selected from the group consisting of H, alkyl, alkylaryl, aryl and O,N-containing alkyl, alkylaryl and aryl groups. 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 vinyl compounds containing heterocyclic nitrogen groups. The resultant diene polymers or copolymers have improved raw polymer viscosity and when compounded with carbon black have good processability in the uncured state and reduced hysteresis in the cured state. The polymers can be utilized to form elastomer compositions for tire treads having reduced rolling resistance.