Isothermal Crystallization Kinetics of Poly(Lactic Acid)/ Montmorillonite Nanocomposites

Abstract

The poly(lactic acid) (PLA)/montmorillonite (MMT) nanocomposites were prepared by melt blending the PLA with commercial organically modified MMT, Cloisite R 30B. The effect of MMT content on the crystallization behavior of PLA/MMT nanocomposites was investigated using the DSC, POM, and XRD. The isothermal crystallization the of organically-modified MMT induced more heterogeneous nucleation effectively increased the crystallization rate of PLA and decreased the activation energy. Itroduction Poly(lactic acid) (PLA) is a linear aliphatic polyester synthesized from lactic acid monomer that obtained from renewable resources, such as corn and potato [1]. In addition, PLA is an environment-friendly biodegradable polymer in contrast to products from petroleum feedstocks. The physical properties, mechanical properties and degradation rate of PLA strongly depend on the structure, morphology and crystallinity of the polymer. In recent years, PLA nanocomposites have attracted interests because the addition of layered silicates can enhanced the physical properties and crystallization behavior when compared to those of polymer matrix. In this research, we used commercial organically modified montmorillonite (MMT) as a filler to fabricate PLA/MMT nanocomposites using melt compounding. The crystallization behavior of PLA/MMT nanocomposites was investigated by XRD, POM and DSC. The isothermal crystallization kinetics and melting behavior of PLA/MMT nanpcomposities will be discussed [2-5], especially the parameters of crystallization such as the lateral-surface and fold-surface energy as well as the activation energy.