Reactively extruded ecocomposites based on poly(lactic acid)/bisphenol A polycarbonate blends reinforced with regenerated cellulose microfibers

Abstract In this study, composites based on micro-cellulose reinforced Polylactic acid (PLA)/Bisphenol A Polycarbonate (PC) reactive blends with different fiber contents are investigated in terms of their mechanical properties, thermal resistance, and dynamic mechanical behavior. In particular, the elastic modulus of the blends was improved thanks to both the addition of fibers and the occurring of the reactive process, as well as the thermal resistance investigated by thermo-gravimetry. The preparation of the composites by melt extrusion in the presence of triacetin and tetrabutylammonium tetraphenylborate (TBATPB) allowed improving the adhesion between the two polymeric phases and the interaction between fibers and polymer matrix, as demonstrated by selective extraction of polymers and infrared analysis of the obtained residual fraction, showing weak stretching vibration of ester groups chemically bonded to microcellulose fibers. The processing of the composites in the melt resulted in fiber length decrease and this effect was quantitatively considered determining the fiber length distribution for all the compositions. The obtained values as well as the consequent final properties are then discussed keeping into account all the experimental results and the reactive mechanism occurring during extrusion.