Thermoplastic Composites Based on Renewable Natural Resources: Unplasticized PVC/Olive Husk

Abstract

The current study explores the potential of eco-friendly biomaterials, namely olive husk (OH) as a reinforcing filler for PVC composite. Thus, composite-based unplasticized poly(vinyl chloride) (u PVC) and olive husk were mixed by a Brabender two-roll mill at 180°C and 25 rpm. The olive husk concentration was progressively varied from 0–20 phr. The fabricated samples were inspected with respect to their tensile properties, impact strength, thermal stability, and density and water uptake. It has been found that stress at peak increased with filler loading up to certain loading. This scenario was related to hydrogen bond formation due to polar-polar interactions. Evidence of the hydrogen bond formation between the polymer matrix and the olive husk was examined with the aid of attenuated reflectance infrared spectra (ATR-IR). Such interactions were cited to justify the improved performance of the composites. Fracture mode and filler dispersion of the composites were compared to the unfilled counterpart by scanning electron microscopy (SEM). The influence of olive husk on the thermal stability of the PVC composites was studied by differential scanning calorimeter (DSC). It has been found that the enthalpy of fusion was improved with OH loading. The observed trend was correlated with the phenolic hydroxyl group of the lignin component used as an antioxidant.