In situ synthesis and characterization of polypropylene with an MgCl ₂ -supported Ziegler-Natta catalyst containing polymer nucleating agents

Compared with traditional nucleation technology, in situ nucleation technology introduces nucleating agents into polyolefins during the polymerization of olefins rather than during subsequent processing granulation. This approach is intriguing and merits further investigation. In this study, a MgCl 2 -supported Ziegler-Natta catalyst containing a polymer nucleating agent was used to catalyze propylene polymerization, resulting in the formation of nucleated polypropylene. Characterization tests revealed that the presence of the polymer nucleating agent during propylene polymerization had minimal impact on the catalytic activity but led to a reduction in isotacticity, an increase in crystallinity, and a higher content of both large and small molecular components. Compared with traditional nucleated polypropylene, in situ nucleated polypropylene prepared at lower concentrations of nucleating agents exhibited superior rigidity, toughness, and heat resistance. By exploiting the high efficiency and uniform dispersion of polymer nucleating agents, high-performance homopolymer polypropylene can be effectively synthesized.