An experimental investigation followed by fundamental characterization and discussion on the effect of nanoclay filler on the mechanical and fracture properties of polymer matrix was carried out. The study was carried out on clay/polymer nanocomposite made of High Density polyethylene (HDPE M40060) produced by Saudi Arabian company SABIC and montimorillonite MMT nanoclay (Nanomer I.34TCN) produced by Nanocore, USA. MMT nanomer I.34TCN is surface modified with organic surfactant to facilitate the bonding between nanoclay and HDPE. Current clay/polymer nanocomposite CPNC was produced by special technique of mixing, processing and molding. Samples of nanoclay, HDPE and nanocomposite were characterized by XRD, SEM and EDAX for investigating the chistillanity, distribution, desperion, intercalation, exfoliation, homogenity and defects. These aspects govern CPNC processing and bond between nanoclay and HDPE which controls the mechanical and fracture properties. Sheets of the produced CPNC were prepared for mechanical and fracture testing. Mechanical properties such as tensile strength, yield stress and elongation were tested and compared for both of pure HDPE and CPNC using non standard test specimens of flat sheets for comparison purposes. Fracture mechanics tests for checking and comparing the critical stress intensity factor due to stress concentration at the crack tips for mode I crack (K_Ic) were carried out using precracked non standard flat sheet specimens subjected to uniaxial uniform tensile stresses. Furthermore, standard experimental tests were conducted for both of HDPE and CPNC for investigating standard mechanical properties aspects based on ASTM D 638 using standard dumbbell-shaped specimen while for investigating standard fracture toughness standard single edge notch specimens SENB subjected bending moment due to effect of 3-point load based on ASTM D 5045 were carried out. The results showed that procedures of mixing, processing technique could produce nanocomposite with enhanced mechanical and fracture properties.

A new natural nanomaterial in Saudi Arabian soil has been explored. It is green nanoclay consisting of two-dimensional nanoparticles with special properties and dimensions. These nanoparticles are called Saudi halloysite-like nanotubes (SHNTs) because they are similar to halloysite nanotubes (HNTs). SHNTs are transparent having a special cross-section in polygonal shapes, such as hexagonal, with unique dimensions in comparison to that of HNTs. Additionally, external width of SHNTs is 20–50 nm, length is 50–600 nm and can reach 10,000 nm while lumen width of SHNTs is larger than that of HNT, along with SHNTs having thinner walls; these attributes make SHNTs good as nanocontainer. Surface area of SHNTs (168 m²/g) is larger than surface area of HNTs (65 m²/g). SHNTs are bendable with a slight curvature, while HNTs are always straight. Geometry, dimensions, microstructure, chemical composition, surface area and zeta potential of SHNTs are characterized using SEM, TEM, EDX, Langmuir surface area technique, a laser particle size analyser and ZP analysis. SHNTs have many applications in industrial, medical and advanced nanocomposite production. Experimental work has been carried out on nanocomposites made of HDPE reinforced with 5% SHNTs, proving enhancements in mechanical, fracture and thermal properties of original HDPE materials.