Effect of magnesium malonate on the formation of the β crystalline form in isotactic polypropylene

Magnesium malonate (MgMt) is used to induce the 11 crystalline form in isotactic polypropylene (iPP) for the first time. It is shown by wide angle X-ray diffraction, differential scanning calorimetry, and polarized light microscopy that the content of the beta crystalline form increases markedly with the addition of MgMt and attains the maximum value at an MgMt content of 0.10 wt%. The tensile strength and flexural modulus of the doped iPP sample decrease somewhat; the tensile strain at break increases slightly; and the Izod notched impact strength increases significantly with the addition of MgMt, as compared with the values for the blank iPP sample. The beta-nucleation mechanism of MgMt is analyzed by the dimensional lattice match criterion.