Abstract: The crystalline syndiotactic 1,2-polybutadiene was synthesized in a catalytic system consisting of iron acetylacetonate [Fe(acac)₃], triisobutylaluminum [Al(i-Bu)₃] and diethyl phosphite (DEP), and its morphological structure waSInvestigated by transmission electron microscopy (TEM).The polymer with a melting point 179℃ was found to have 89.3% 1,2 polybutadiene and 86.5% syndiotacticity based on ¹³CNMR measurements.The bright field electron micrograph shows that the solution cast film of syndiotactic 1,2-polybutadiene consists of lamellae with lateral scale in micron size.It should be noted that the lamellae have no branching and they are almost parallel each other in localized areas.The lamellar growing direction is along b axis.Surprisingly, the electron diffraction pattern of the film only exhibits strong (hko) reflections, which indicate that the lamellae possess a single crystal-like orientation, i.e., with their c axis perpendicular to the film plane, while a and baxeSIn the film plane.According to the orthorhombic packing of plane zigzag chains, the cell parameters calculated from the electron diffraction pattern are a=1.102 nm, b=0.664 nm, respectively, which are completely consistent with the results reported by Natta et al..

Key words: Syndiotactic 1,2-polybutadiene, Synthesis, Morphological structure, Transmission electron microscopy