Crystal Growth Dynamics in Binary Blends of iPP and aPP

The overall free energy is given as a weighted addition of the local and nonlocal free energies in and j fields, namely 

Xca and F can be related to physical parameters such as experimentally accessible material parameters and experimental conditions. These model parameters are shown explicitly to be supercooling dependent. Equations 7.15 and 

16 were solved numerically in one-dimensional (1 x 200) and two-dimensional square lattices (1024 x 1024) using an explicit central difference scheme for spatial discretization and explicit forward difference scheme for time steps with periodic boundary condition (46,47). 

The possible entrapment of aPP in the core of iPP spherulite was first reported by Lohse and coworkers based on small-angle neutron scattering and thermal analysis experiments (52, 53), who found that aPP and iPP are not only miscible in the melt, but also the atactic PP chains can be trapped inside the spherulites of iPP on a scale comparable to that of the crystalline lamellae. Billingham and coworkers (48) emphasized the rejection of the amorphous concentration at the growing front, but 

Elastomeric polypropylene was provided by Exxon Chemical Company. The weight-average and number-average molecular weights of ePP were reported to be 32,000 and 6100gmoD, respectively, with apolydispersity (Mw/Mn) of 5.22. 

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