Synthesis and Effect of N,N'-Diphenylterephthalamide on Crystallization of Isotactic Polypropylene

Abstract A phenyl-substituted terephthalamide β-nucleating agent, N,N '-diphenylterephthalamide (DPTH) was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and 1 H nuclear magnetic resonance ( 1 H NMR). DPTH’s effect on the crystallization and melting behaviors in isotactic polypropylene (iPP) was investigated by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarizing optical microscope (POM). The results illustrated that DPTH was an effective β-nucleating agent for iPP. The relative content of β-crystal ( k β ) increased with the rise of the DPTH content and reached a maximum of 0.652 at 0.6% DPTH content. The Avrami and Jeziorny methods were used to describe the nonisothermal crystallization kinetics of iPP. Higher crystallization rate constant Z c and lower halftime of crystallization t 1/2 were obtained in iPP containing DPTH.