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This study details about the synthesis of micro-crystalline cellulose prepared from olive pits, the waste material obtained in olive industry, and the effect of these fillers on the tensile and thermal properties of polyvinyl alcohol/starch blends. Micro-crystalline cellulose from olive pits was prepared, and its size was measured using particle size analyzer. Composites were prepared for various micro-crystalline cellulose loading (0, 1, 3, and 5 wt.%) by solution casting method for the blend ratio of 70/30, respectively. Glycerol (3.78 g) was used as plasticizer in all formulations. Universal testing machine, thermogravimetric analyzer, differential scanning calorimeter, X-ray diffractometer, and scanning electron microscopy were used to study the tensile, thermal, and surface morphology of these bio-composites. Results indicated an increase in the tensile properties especially the Young's modulus from 100 to 180 MPa for composites having 1 wt.% of micro-crystalline cellulose and the same formulation showed higher thermal stability.

Ni-Al layered double hydroxide/graphene hybrid fillers were prepared via coprecipitation method. The structural and thermal studies of these fillers were conducted using X-ray diffractometer (XRD) and thermogravimetric analyzer (TGA). Subsequently, by using solution casting method, these fillers were introduced into the polyvinyl alcohol (PVA)/starch matrix as reinforcing agent. For the composites, characteristic peaks of Ni-Al-LDH/graphene disappeared irrespective of filler content. TGA showed an increase in the initial degradation temperature (234-242 C) when filler content was increased from 0 to 2 wt%. Differential scanning calorimeter (DSC) analysis exhibited an increase in heat of fusion (ΔH m), melting temperature (T m) and percentage crystallinity values for the PVA/ starch matrix having 1 wt% of filler. Similar trend was observed for tensile strength and Young's modulus of composites. Scanning electron microscopy (SEM) showed a homogeneous distribution of filler throughout the matrix.