Preparation of syndiotactic polyolefins by using metallocene catalysts

Summary Polyolefins having syndiotactic structure were obtained by using 1-methyl-1-ethylidene-(cyclopentadienyl-1′-fluorenyl) zirconium dichloride and methylaluminoxane as a catalyst. 1-Butene and 4-methyl-1-pentene gave crystalline polymers having syndiotactic structure, while 1-pentene, 1-hexene and 1-octene gave noncrystalline polymers having syndiotactic structure. The identification of syndiotactic and isotactic polyolefins was made by ¹³C-NMR, X-ray diffraction, and differential scanning calorimetry.