Study of the Assembled Morphology of Aryl Amide Derivative and Its Influence on the Nonisothermal Crystallizations of Isotactic Polypropylene

The nonisothermal crystallization behaviors of isotactic polypropylene (iPP) with an aryl amide derivative TMB-5 as beta-form nucleating agent has been investigated by differential scanning calorimetry, X-ray diffraction, and polarized optical microscopy. The feature of crystallite morphology depends on concentration and thermal conditions. At low concentrations, TMB-5 molecules aggregate into fibril. structures and presented blunt exothermic peak with a shoulder at high temperature. The surface of these fibrils host active sites tailored for the nucleation of beta-iPP, represented by clusters of microcrystallites. With increasing concentration, alpha beta-transcrystalline layer develops on the lateral surface of needle-shaped TMB-5. Enhanced multiple endotherms indicate the ensuing crystals are less perfect and easily transformed into more stable forms. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 314-325, 2009