Stereospecific polymerization of butene-1 with supported titanium catalyst

Butene-1 was polymerized with a highly-active supported titanium catalyst which was developed in this laboratory. The influences of various conditions (e.g., catalyst composition, temperature, external ester, H₂, triethylaluminum, and catalyst concentration) on the catalytic activity, decay of polymerization rate, molecular weight, and isotacticity of the products were studied in detail. The structural properties of the PB-1 were characterized by WAXD, DSC, and ¹³C-NMR. It was found that the catalyst TiCl₄, Ti(OBu)₄/MgCl₂/ethyl benzoate (EB)/Ph₂SiCl₂–AlEt₃ shows high activity, i.e., 3.2 × 10⁴ g PB/g Ti h. Isotacticity of the product was increased by adding p-CH₃C₆H₄COOEt into the catalytic system. Molecular weight of the product can be easily controlled by H₂. The decay of polymerization rate with time fulfills the equation: R_t ? R_s = (R_o ? R_s)e^?βt. © 1993 John Wiley & Sons, Inc.