Fabrication and Properties Study of Well-Dispersed Fillers Reinforced <i>cis</i>-1,4 Polybutadiene Composites

Synthesis of functional cis-1,4 regulated poly(1,3-diene) via coordination polymerization is of great significance in both academic and industrial fields but has been a challenging task. In this work, 1,10-phenanroline has been ortho-modified with alkyl(aryl)ether, thioether, and amine and installed onto cobalt dichloride. With the aid of the neighboring group in the ligand, high cis-1,4 copolymerization of butadiene and hydroxyl modified myrcene has been demonstrated. The polymerization gave rise to copolymers with functionality fraction up to 45.6 mol % without reducing either polymer yield (>82.7%), cis-1,4 regularity (95.1%–96.9%) or molecular weight (3.2–7.9 × 104 g/mol), which has never been achieved before. More importantly, excellent tensile strength, elongation at break, and dynamic properties have been integrated. These advantages are attributed not only to the strengthened interfacial interaction between hydroxyl-modified polybutadiene and hydrophilic silica but also to the promoted dispersion of silica layers in the rubber matrix. The copolymerization capability promoted by this cobalt catalyst would contribute to the development of advanced poly(1,3-diene)s for energy-saving green tire materials.