β-Crystallization and mechanical properties of aluminum hydroxide-filled polypropylene composites

In order to provide aluminum hydroxide with β-nucleating surface (β-ATH) for PP crystallization, the calcium pimelate supported on the surface of ATH was prepared through chemical reaction between calcified ATH and pimelic acid in our lab. The β-ATH particles were characterized by Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy and scanning electron microscopy. Effect of ATH, calcified ATH, and β-ATH on crystallization and crystalline modification of PP was investigated by differential scanning calorimetry. The results indicated that the prepared β-ATH has higher heterogeneous nucleation than ATH and calcified ATH for PP crystallization. Addition of ATH and calcified ATH has no influence on the crystalline modification of PP. The β-ATH can induce the formation of β-crystal in the ATH-filled PP composites with β-crystal content of above 90%. The transformation of surface nucleation mechanism of ATH from α-nucleation into β-nucleation was investigated. The effects of β-ATH content, mass ratio of calcified ATH/pimelic acid and concentration of calcium acetate solution in the preparation of calcified ATH on the heterogeneous nucleation and β-crystal content of β-ATH-filled PP composites were discussed. The mechanical performance of the prepared β-ATH-filled PP composites were also characterized. POLYM. COMPOS., 2017. © 2017 Society of Plastics Engineers