Morphology and crystallization kinetics of dilute binary blends of two monodisperse n-alkanes with a length ratio of two

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Description/Abstract

The crystallization kinetics and morphologies of dilute binary blends of the monodisperse alkane n-C122H246 in n-C246H494 and vice versa have been investigated. With a molecular length ratio close to two, this pair of n-alkanes does not produce permanent cilia when once-folded C246H494 molecules cocrystallize with extended chains of C122H246. In this condition, the supplementary splaying of adjacent dominant lamellae and the consequently more spherulitic textures, which are present in previous blends for which a longer guest molecule gives permanent cilia, are absent, although other features of blend crystallization remain. Specifically, the isothermal radial growth rate is constant for cocrystallizing blends, although less than for their pure hosts, but becomes nonlinear with cellulation when C122H246 forms a segregated population within extended-chain C246H494. Increased nucleation in the blends give smaller scale textures than for the host materials, but the presence of a second component reduces splaying and thereby disfavors spherulitic growth.