Morphology and properties of nanostructured materials based on polypropylene/poly(butylene succinate) blend and organoclay

Nanostructured materials based on organically modified montmorillonite (OMMT) and polypropylene (PP)/poly(butylene succinate) (PBS) blend were prepared via melt-mixing of PP, PBS, and OMMT in a batch mixer. The weight ratio of PP and PBS was 70:30, and the OMMT loading varied from 0.5 to 5 wt%. The surface morphologies of unmodified and OMMT-modified blend were studied by field-emission scanning electron microscopy. Results showed that the particle size of the dispersed PBS phase was significantly reduced with the addition of a small amount of OMMT (1.5 wt%). Upon the addition of 5 wt% of OMMT, the domain size of the dispersed PBS phase changed significantly from the unmodified blend, and a homogeneous dispersion of very fine particles of PBS was observed. The degree of dispersion of silicate layers in the blend matrix was characterized by X-ray diffraction and transmission electron microscopy. The improved adhesion between the phases and the fine morphology of the dispersed phase contributed to the significant improvement in the properties and thermal stability of the final nanocomposite materials. On the basis of these results, we describe a general understanding of how the morphology is related to the final properties of OMMT-incorporated PP/PBS blend.