Investigation of polybutylene succinate-co-adipate (PBSA)/montmorillonite layered silicate (MLS) melt-processed nanocomposites

Biodegradable nanocomposites were prepared with polybutylene succinate adipate (PBSA) and three organically modified montmorillonite layered silicates (MLSs) by melt-extrusion methods at three screw speeds (20, 40, and 60 rpm) to determine the interaction and properties of the polymer/ MLS nanocomposites. The samples were evaluated by X-ray diffraction (XRD) and transmission electron microscopy (TEM) to determine the level of MLS interaction with PBSA. All formulations formed varying degrees of intercalation regardless of the modification of the MLS or the variation of the screw speed upon melt processing. Differential scanning calorimetry (DSC) experiments did not reveal significant differences in melt temperature or glass transition temperature of PBSA. Dynamic mechanical analysis did display improved modulus values as a function of temperature with some of the nanocomposite formulations processed at different screw speeds. Extensive biodegradation tests were performed and determined that the nanoparticles did riot hinder biodegradation in soil. Toxicity tests also were performed and all samples proved to be nontoxic.