Comparative study of some mechanical properties of nanocomposites based on the polymer's blends used for dentures base applications

Abstract

Recently, high mechanical and physical properties of PMMA material have encouraged many researchers to work in the denture's applications. However, it is a weak material in terms of fatigue loads and impact strength. In the present research, two types of polymer blend nanocomposite samples were manufactured by utilizing a hand lay-up method used to produce the complete or partial dentures base. Polymer blends containing (poly methyl methacrylate resin and 2% natural rubber (NR)) were used as matrix; it was strengthened by two kinds of natural powder in the nanometer size of clove powder and pomegranate peels powder (PPP) individually, with a chosen weight fraction percent of (0.0, 0.1, 0.3, 0.5 and 0.7% wt). The results manifested appreciably the advanced values of flexural strength, flexural modulus, maximum shear stress, fracture toughness and impact strength for both kinds of hybrid composites specimens compared to matrix material (PMMA: 2%NR). Composite specimens of polymer blend (PMMA: 2%NR) matrix reinforced by (PPP) elucidated the highest values for these properties as compared with their counterpart of nanocomposites, which reinforced by clove nanoparticles. The highest values for the flexural strength and maximum shear stress reached to 144 MPa and 3 MPa, respectively at 0.5% ratio of PPP, whereas the highest values of flexural modulus, impact strength and fracture toughness reached to 3.3 GPa, 10 KJ m-2 and 5.74 MPa.m1/2, respectively at 0.7% ratio of PPP for polymer blend nanocomposite (PMMA: 2%NR: 0.7% PPP). Depending on these results, it can be concluded that the addition of natural fillings in a nanometer size of pomegranate peels or clove powders individually to the polymer blend (PMMA: 2% NR) material is one of the promising materials that can be used to improve the mechanical properties, especially the fracture strength for the complete or partial dentures base.