Hybrid biocomposites based on polylactic acid and natural fillers from Chamaerops humilis dwarf palm and Posidonia oceanica leaves

Platelet-like and fibrous lignocellulosic fillers were achieved from the leaves of Chamaerops humilis (CHL) and Posidonia oceanica (POL) and used as a hybrid reinforcement for a polylactic acid (PLA) matrix at three different loading levels (from 5 to 20%). The materials were fully characterized from a morphological, physicochemical, mechanical, and dynamic-thermomechanical point of view. When compared to their counterpart containing either CHL or POL only, the resulting hybrid biocomposites showed the highest mechanical properties, with strengthening and stiffening effects respectively up to 120% and 50% higher than those expected from the linear combination of the two, and higher dynamic-mechanical performance, with storage moduli in the rubbery region 10 times higher than those of composites containing solely CHL or POL. Such synergistic efficiency is likely due to the formation of a strong and extensive interphase region, promoted by the balanced effect of morphological features of the hybrid network and physicochemical characteristics of the components. These green materials could find applications as panels for furniture or in the automotive industry.