Effect of interface affinity on the performance of a composite of microcrystalline cellulose and polypropylene/polylactide blends

Abstract

The effects of compatibilizer and fillers on the mechanical properties and dispersion state of droplets of polypropylene (PP)/polylactide (PLA) blends were investigated. Two blended composite systems, i.e. PP-rich (80/20) containing microcrystalline cellulose (MCC) modified with silane (m-MCC) and PLA-rich (20/80) containing MCC were prepared by melt compounding using a twin-screw extruder. The structural differences between MCC and m-MCC were confirmed using Fourier transform infrared spectra. Universal testing machine results revealed that the tensile strength and Young's modulus increased with the addition of compatibilizer and filler, respectively. These results were supported by the reduction of domain size observed by scanning electron microscopy. Differential scanning calorimetric analysis showed a change of the melting and crystallization behavior of blends according to the presence of compatibilizer or filler. An increase of the dynamic storage modulus and a decrease in tan delta with addition of compatibilizer indicated that the interfacial adhesion between PP and PLA improved.