Crystallinity and isotactic index of polypropylene samples prepared by VOCI3 and aluminum alkyls

Abstract The X‐ray crystallinity and the isotactic index [II(%)] values were measured for polypropylene (PP) samples prepared by VOCI3 and various aluminum alkyls. The reaction parameters, such as aging time, temperature, reaction medium, and additives, have some effect on the crystallinity of the samples. Among the three systems studied, a combination of VOCI3 + Et2AICI was found to give PP with higher crystallinity and II. In general, the tacticity of the samples prepared were much lower than the samples prepared with α‐, β‐, γ‐TiCl3 as the catalyst.