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 VOCI 3 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 VOCI 3 + Et 2 AICI 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‐TiCl 3 as the catalyst.