Abstract:

Polypropylene （PP） produced through current industrial processes has typical drawbacks such as poor thermal properties， electrical properties， and optical properties， especially under extreme conditions like low temperatures or high strain rates. These issues can often be addressed by adding nucleating agents. Nucleating agents can induce heterogeneous nucleation in PP， leading to a further refinement of the crystalline structure. In this case， there is an increase in the crystallinity of PP and a reduction in the diameter of spherulites， thus improving the various properties of PP. Starting from the types of nucleating agents for PP， this paper introduced different categories of alpha⁃crystalline nucleating agents （inorganic and organic types） and beta⁃crystalline nucleating agents （inorganic， polycyclic aromatic hydrocarbons， rare earth compounds， etc.） as well as their respective characteristics. Based on this foundation， the paper also reviewed the recent development in the nucleating agents for PP and summarized their nucleating effects on the performance modification of PP. Finally， an outlook was provided for the research direction of nucleating agents of PP in combination with their practical applications.

Key words: polypropylene, nucleating agent, polymer, mechanical property, thermodynamics