Converting polymer-wastes to green nanocomposites in Saudi Arabia: Investigation of fracture parameters (KIc, KIIc, θc, σc) for quality and sustainability evaluation

Abstract

The intrinsic fracture-parameters including fracture-envelope (KI-KII), fracture-direction (θc) and fracture-load (σc), are predicted experimentally at different crack inclination-angle (β) for each of pure-original polyethylene (HDPE, LDPE) and advanced green-nanocomposite CPNC made of (95%) recycled waste polyethylene (HDPE, LDPE) and (5%) montmorillonite MMT nanoclay NC. These fracture factors represent evaluation of material quality and sustainability. These fracture parameters are investigated experimentally and compared with characterization of microstructure, interfacial-bond, chemical composition, and crystallinity. These parameters are depending on material type, crack type, crack-location, crack-shape, crack-geometry, crack-orientation, crack-dimensions, and loading type. Nanocomposite called clay-based polymer nanocomposite CPNC is produced of recycled polymers with special mixing technique with (5%) surface modified natural nanoclay. Pre-cracked recycled-CPNC, HDPE and LDPE samples are tested with different crack-orientations of central cracks and edge cracks under far-field tension load. Characterizations of microstructure, bond and chemical composition are conducted by SEM and EDAX for investigating the differences between original and recycled materials. The results are compared to each other with detailed discussion showing good results of converting of contaminated waste-materials to valuable advanced green ecofriendly nanocomposite suitable for different fields like medical applications, dental biomaterials for orthodontics, dental-restoration for fracture under caries and occlusal stresses and other industrial applications.