Abstract: In this paper, the effect of chain structure, molecular weight and its distribution on the processibility and vulcanizate's properties of 1,2-polybutadiene (1,2-PB) synthesized with molybdenum based catalyst was studied.It is shown that its yield strength (σ_y) increases, plasticity decreases but millibility, extrudability and stock adhesion become poorer with increase of the molecular weight of 1,2-PB.When [η] was over 3, processing oil had to be added during mixing, otherwise, the mixed stock was too crumbly to be sheeted out. In addition, the cord adhesion for 1,2-PB vulcanizate decreases with increase of molecular weight of polymer. Results indicate that the Wet-skid resistance of 1,2-PB vulcanizate is enhanced as its 1,2 unit content increases. Raising syndyotactic content would lead to strain induced crystallization.When syndyotactic content was 20%, the critical intrinsic viscosity [η]₄ was 4, above which strain ind uced crystallization could appear.The stock adhesion,as well as the resilience of 1,2-PB vulcanizates would obviously decrease with raised syndyotactic content.

Key words: 1,2-Polybutadiene rubber, Molecular weight, Molecular weight distribution Processibility, Molybdenum catalyst