Development of new biodegradable composites materials from polycaprolactone and wood flour

Abstract

ABSTRACT The use of polymeric materials for the sustainable packaging sector is constantly improving due to meet the required properties for the application. However, most polymers come from non-renewable sources and can harm the environment, if inappropriately disposed. Therefore, this study aims to develop environmentally friendly composites based on polycaprolactone (PCL), a biodegradable polymer, reinforced with different contents (0, 5, and 15 wt%) of wood flour (WF), a residue of the timber industry. The samples were processed using a co-rotational twin screw extruder, followed by hot pressing. Water absorption test, contact angle, thermal aging test, Izod impact resistance, tensile tests, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) were performed. By the results, it was possible to verify that the presence of WF contributed to the degradation by hydrolysis due to its hydrophilic character. As the WF content increased, mainly for the PCL/15 wt% WF composite, the material became rigid due to a 61% increase in the Young’s modulus in relation to the neat PCL. The composite’s morphology characteristics showed good interfacial adhesion of the WF with the PCL matrix. The PCL/5 wt% WF composite showed very satisfactory results in terms of mechanical and thermal properties, in addition to a good interaction with the PCL matrix.