Influence of Nano-hydroxyapatite on the Mechanical Properties of Short-carbon-fiber/Poly(methyl methacrylate) Bio-composites

Abstract

<FONT face=Verdana>An <EM>in-situ</EM> processing combined with solution co-mixing approach was developed in the preparation of poly(methyl methacrylate)(PMMA) matrix bio-composites using hydroxyapatite (HA) nano-particles and short carbon fiber (C<SUB>f</SUB>) as reinforced materials. The influences of HA particles on the mechanical properties and microstructures of the HA-C<SUB>f</SUB>/PMMA composites were investigated. The mechanical properties were tested by universal testing machine. The phase compositions and fracture surface morphologies of the asª²prepared HA-C<SUB>f</SUB>/PMMA composites were characterized using X-ray diffraction (XRD), transmission electron microscope (TEM), field emission scanning electron microscope (FESEM) and Fourier transform infrared spectroscope (FT-IR). The results show that the interface bonding between HA and PMMA matrix and the mechanical properties of HA-C<SUB>f</SUB>/PMMA composites are obviously improved by surface modification of HA with lecithin as coupling agent. With the increase of lecithin-modified HA mass fraction, the flexural strength, tensile strength, compressive strength, flexural modulus and tensile modulus of the as-prepared HA-C<SUB>f</SUB>/PMMA composites firstly increase and then decrease. When the surface modified HA particles mass fraction is 8%, the dispersion of HA nano-particles in PMMA matrix is uniform and the flexural strength, tensile strength, flexural modulus and tensile modulus of the HA-C<SUB>f</SUB>/PMMA composites reach the maximum value.</FONT