Synthesis, Structure, and Properties of Poly(isoprene)s of Different Constitutions and Configurations from Catalysts Based on Complexes of Nd, Co, and Fe

Poly(isoprene)s of different molecular structures have been synthesized with various catalysts based on complexes Nd-, Co-, and Fe-bearing pyridylimine, phosphine, bipyridine ligands. essentially cis-1,4 structure, 3,4 syndiotactic regular alternating cis-1,4-alt-3,4 structure obtained. Moreover, polymers an unusual prevalent but containing units sequences lengths (3 or 5 units) within the chain also The mechanical properties all poly(isoprene)s, some them completely new, investigated. a perfectly are amorphous, exhibiting behavior viscous flow at relatively high deformation. sample poly(isoprene) almost (about 79% crystallizes in stable orthorhombic form 3,4-syndiotactic poly(isoprene). This crystalline shows better deformability flexibility than other amorphous poly(isoprene)s without plastic deformation breaking strain around 300–400% remarkable elastic properties. associated reversible transformation during tensile into disordered mesomorphic form, which recrystallizes upon relaxation recovery. glass transition temperature decreases linearly increasing content, from 16 °C 21% to −64 98% units.