Preparation and Properties of Polylactide/Layered Silicate Nanocomposite

New biodegradable polylactide (PLA) /layered silicate nanocomposites were prepared successfully by simple melt extrusion of PLA and organically modified layered silicate (OMLS). Natural montmorillonite or synthetic fluorine mica modified with several kinds of ammonium cations were examined as OMLS for the intercalated-type nanocomposites preparation. The internal structure of the nanocomposites in the nanometer range has been established by using wide-angle X-ray diffraction and transmission electron microscope analyses. All the nanocomposites exhibited superior improvements of practical material properties, such as storage modulus, flexural modulus, flexural strength, heat distortion temperature, and gas barrier property as compared with the corresponding values of PLA without OMLS. The biodegradability of neat PLA and representative nanocomposites was also studied under compost environment. The rate of biodegradation of PLA matrix significantly increased after nanocomposite preparation.