Functionalization and Properties of Olive Wood Shell Stone and Its Use in Polyester Biocomposites

Abstract

The use of olive wood shell stone (OS) as a revalorized agri-food residue has been investigated for the development of new biocomposites in which a significant amount of the mineral filler is substituted by olive wood stone (APTMS). In addition, we have explored the functionalization of olive stone with different types of coupling agents that are known to improve adhesion between the lignocellulosic matrix and, in our case, unsaturated polyester resin as the most used binder in composite materials. The new functionalized materials have been thoroughly characterized by means of X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectra (ATR and FTIR-DRIFT), ζ-potential, elemental analysis, XRF, pore size distribution, differential scanning calorimetry (DSC), thermogravimetric (TG), moisture content and particle size distribution. The mechanical and thermal properties of the resulting composites have been evaluated, showing promising results with very good characteristics in flexural strength and heat deflection temperature (HDT), but with lower Barcol hardness and Young's modulus compared to those based on feldspar as an inorganic filler.