Influence of a Novel Beta-Nucleating Agent On the Structure, Mechanical Properties and Crystallization Behavior of Isotactic Polypropylene

A novel β nucleating agent of isotactic polypropylene (iPP), zinc bicycle [2.2.1] hept-5-ene-2-dodecylamine-3-carboxylate (NBDA-30),was found and its effects on the mechanical properties, content of β crystal, and crystallization behavior of iPP were investigated. The results showed that the NBDA-30 could significantly improve the impact strength of the polypropylene. When NBDA-30 content was 0.8 wt%, the impact strength of iPP increased from 31.8 J / m to 91.0 J / m, which was nearly 3-fold compared with pure iPP. The β crystal content (k value) of iPP firstly increased and then decreased with the increasing of NBDA-30 content. When the content of NBDA-30 was 0.2 wt%, the k value reached the maximum value of 81.7%, which indicated that NBDA-30 was a highly efficient β crystal nucleating agent of iPP. NBDA-30 could significantly improve the crystallization peak temperature and obviously reduce the size of the spherulites of the polypropylene. Finally, Caze equation was used to study non-isothermal crystallization kinetics of pure iPP and iPP nucleated with NBDA-30.