Effect of a novel family of N,N'-diphenyl bisamides on the formation of β crystalline form in isotactic polypropylene

Abstract

In this paper, a family of eight N,N-diphenyl bisamide compounds were synthesized and characterized by fourier transform , infrared (FT-IR) and 1H nuclear magnetic resonance (NMR) technologies. The influence of different compounds on the formation of β crystalline form in iPP had been investigated by means of wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarized light microscopy (PLM). N,N -diphenyl succinamide (DPS), N,N -diphenyl glutaramide (DPG) and N,N'-diphenyl adipamide (DPA) are β-nucleating agents for iPP among these compounds. The results also indicate that DPS and DPA have higher ability to induce the β-form than DPG. The analysis of the cell parameters of three efficient β-nucleating agents shows that they all have approximate periodic length of b-axis of 0.65 nm. And it is also suggested that two-dimensional lattice matching relationships exist between the crystal structures of the β-nucleating agents and that of β-iPP. ©2009 The Society of Polymer Science.