Crystallization of post-consumer polypropylene in the presence of β-nucleating agent

In order to investigate the crystallization behavior of post-consumer waste polypropylene (PCW-PP) in the presence of an aryl amide derivative β-nucleating agent (TMB-5), differential scanning calorimetry (DSC), wide-angle X-ray diffraction and polarized-light optical microscopy were used. The content of calcium carbonate (CaCO₃) in four kinds of PCW-PP, as well as the relative β-content of PCW-PP nucleated by 0.3 mass% TMB-5, is estimated by thermogravimetric analysis and DSC. The results indicate that the commercial grade TMB-5 has strong β-nucleating effect on the crystallization of PCW-PP and increases the crystallization temperature of PCW-PP in the presence of different content of CaCO₃ with α-nucleating effect. As a result, PCW-PP with β-phase content higher than 75% is prepared through the addition of 0.3 mass% TMB-5, which has significance for high-value added recycling of PCW-PP.