Crystallization kinetics and crystallization behavior of syndiotactic polystyrene/clay nanocomposites

We investigated the effects of montmorillonite (clay) on the crystallizatio n kinetics of syndiotactic polystyrene (sPS) with isothermal differential s canning calorimetry analyses. The clay was dispersed into the sPS matrix vi a melt blending on a scale of 1-2 nm or up to about 100 nih, depending on t he surfactant treatment. For a crystallization temperature of 240 degreesC, the isothermal crystallization data were fitted well with the Avrami cryst allization equation. Crystallization data on the kinetic parameters (i.e., the crystallization rate constant, Avrami exponent, clay content, and clay/ surfactant cation-exchange ratio), were also investigated. Experimental res ults indicated that the crystallization rate constant of the sPS nanocompos ite increased with increasing clay content. The clay played a vital role in facilitating the formation on the thermodynamically more favorable all-bet a -form crystal when the sPS was melt-crystallized. (C) 2001 John Wiley & S ons, Inc.