Investigations on fatigue analysis and biomimetic mineralization of glass fiber/sisal fiber/chitosan reinforced hybrid polymer sandwich composites

In this study, chitosan/sisal/glass fiber (CS/SF/GF) reinforced hybrid polymer composite for femur bone fracture plate was developed. The CS/SF/GF hybrid composite possesses exclusive sandwich assembly and includes epoxy/GF/CS as the peripheral layers and epoxy/CS/SF as the inner layers. The composite arrangement be similar to the human bone assembly spongy interior cancellous medium and stiff peripheral cortical. The objective of this investigation was to determine the fatigue properties of CS/SF/GF hybrid sandwich composites, because cyclical loading is the foremost loads experienced by a femur plate during normal day to day activities such as walking and running. Tensile and fatigue properties were studied as per ASTM (D3039 and D3479) standards. Morphological behaviour of fractured fatigue samples was considered using scanning electron microscope. The biomimetic activity of CS/SF/GF composites was examined using biomimetic mineralization techniques with the help of simulated body fluid (SBF). The tensile study results proved that the A6 hybrid CS/SF/CTS composites impart higher ultimate tensile strength of 146 MPa and tensile modulus of 6.814 GPa compared to other combinations. The fatigue results revealed that the fatigue life of A5 hybrid CS/SF/GF composites withstand more than 1 million cycles (1.20 x 10(6)) compared to other combinations. The presence of bone like apatite layer (Ca, Sr, Pb, Si, Ba, K, Pd and CI) from Simulated Body Fluid (SBF) onto CS/SF/GF layer were confirmed by XRD, SEM-EDAX and FT-IR. Further, the calcium/phosphate (Ca/P) ratio was found to be approximately 1.67 which is needed for the biological apatite layer formation, this proved the formation of apatite layer on the CS/SF/GF composite surface. The experimental test results proved that GF/SF/CTS/EP hybrid composite can be used for orthopaedic bone fracture plate applications. (C) 2020 The Author(s). Published by Elsevier B.V.