| Abstract: | Isotactic polypropylene (PP) resin was doped with pimelic acid, sodium pimelate, and calcium pimelate to stimulate the growth of hexagonal crystalline polypropylene (β-PP). The doped resin was crystallized in a differential scanning calorimeter (DSC) and during compression molding and injection molding. The effect of the additives on the formation of β-PP was examined using DSC and wide angle X-ray scattering (WAXS). Pimelic acid alone was found ineffective while the pimelates induced 64% to 90% of β-growth depending on the nucleating agent system and crystallization condition. In particular, the pimelic acid/calcium stearate system produced a more consistent and higher yield of β-PP. This was attributed to finer particle size and better dispersion of the nucleating agent. |
