Nonisothermal crystallization behavior of poly(butylene adipate-co-terephthalate)/clay nano-biocomposites

The study of the nonisothermal crystallization behavior of layered silicates micro- and nano-biocomposites based on poly(butylene adipate-co-terephthalate) (PBAT), a biodegradable copolyester, has been carried out with different theoretical models. They were applied and developed with the aim to describe and better understand the influence of the layered silicates dispersion on crystallization. The nucleation efficiency of the layered silicates has been demonstrated with the use of the "Modified Avrami model," thanks to the higher crystallization rate parameter, Z(c), and of the lower crystallization half-time, t(1/2), compared to the neat matrix. The crystallization activation energies, E-a, calculated from "Kissinger's model" have shown that layered silicates have a negative effect on the crystallite growth process. Thus, these analyses have shown that layered silicates have a double effect on the crystallization process. These two opposites' phenomena depend on the dispersion quality and are more pronounced for the intercalated nano-biocomposites. (c) 2007 Wiley Periodicals, Inc.