Biocomposites based on polylactic acid and olive solid waste fillers: Effect of two compatibilization approaches on the physicochemical, rheological, and mechanical properties

A new valorization strategy for Olive Solid Waste (OSW) has been carried out consisting in incorporating this biomass as filler in a biopolymer matrix. In this study, biocomposites based on poly(d,l‐lactide) (PLA) and OSW fillers were prepared with various filler contents. It was highlighted that the inclusion of OSW under high temperatures resulted in the degradation of the matrix leading to a reduction of the viscoelastic properties and molar masses. Nevertheless, it was shown that this degradation of PLA matrix could be attenuated through two approaches. The first was chemical and consisted in using a chain extender agent named Joncryl, containing glycidyl methacrylate (GMA) functions. The second route was physical and involved coating the OSW with the hydrophobic biopolymer poly(ε‐caprolactone) followed by mixing with PLA. Meanwhile, the effect of the OSW with and without Joncryl on the thermal stability, the melt and crystallization properties was assessed. Furthermore, the rheological properties of the controlled systems PLA/OSW/Joncryl and/or PLA/(OSW) coated with PCL were investigated in the molten state. The improvement of the shear viscoelastic properties corroborated the measured molar masses. The physicochemical matrix/filler interactions had to be taken into account to explain the improved rheological, morphological and tensile mechanical properties. POLYM. COMPOS., 39:E152–E163, 2018. © 2016 Society of Plastics Engineers